[d2e]

Hi again forum...

I just learned over the last 5 days about the common issue with old diesels, cold weather and draining the battery when trying to start the car over and over.

Twice now in the last 5 days (the last time being about 1.5 hours ago), I've drained my battery in cold weather by trying to start it.

Today has been the coldest day thus far since I've had my car. Tomorrow the weather is going to be colder.

When I tried start my car after glowing it a couple times first tonight, the battery quickly drained and I had to call a wrecker for a jump while at work. This same thing happened last Friday evening when it got cold and I had to get a jump. I was at work then too.

I don't have to do this in the morning, as my car is garaged AND I plug up the engine block heater overnight. I don't have the option of plugging up the engine heater while at work, however.

I have an Interstate battery, but don't know how old it is since I got the car this July. It doesn't look like a new battery.

Can anyone give advice on what to do? Do I get a new Interstate battery and if so, will it fix this problem? I cannot deal with these jumps since it's getting colder and I have GOT to either find an Interstate battery somewhere tonight, or an alternative at least.

Perhaps I should get a portable battery charger from an auto store? Will that solve my problem for the entire winter?

Thanks, and I appreciate ANY and ALL help.

d2e

 

[wsad]

So was the battery the cause of your previous post regarding starting problems? I've ha...

So was the battery the cause of your previous post regarding starting problems? I've had this problem every winter every year since acquiring my '80 300D, and I just the other day found out what the problem was.

What you need to do is, if you have a multimeter, take the negative cable off the battery. Then measure the current between the negative cable and the negative battery post with the ammeter. Mine was measuring 0.37 amps, or 370 milliamps. That's way too big of a drain to have. After troubleshooting (unplugging various things, disconnecting fuses) I found out what the problem was.

On my car, on the driver's side under the black plastic relay box, theres a wire in there with a fuse holder. I believe that's the fuse for the climate control amplifier. I took that fuse out, measured the current draw at the battery, and guess what, 10 milliamps! 10 milliamps is what it should be at for this car, because the clock and the memory for my CD player are the only things that should be drawing current when the car is off.

I know not all years of this car are set up with this fuse in this location, but mine is a 1980 and yours is a '79, so it could very well be your problem as well. I don't know why this problem occurs when the weather gets cold, but I'm just assuming there's something wrong with the amplifier sticking on, or a relay, or some other problem in its circuit. Hopefully this is your problem as well.

 

[d2e]

wsad,

Glad you chimed in on this one, since you've experienced the same issue. To answ...

wsad,

Glad you chimed in on this one, since you've experienced the same issue. To answer the first question, I don't know if the battery is causing the glow light problem, but I won't rule it out as the culprit. I'm having little luck finding a shop open tonight that has my battery. So far it's got to be ordered.

Thanks for sharing the details in troubleshooting. I'll try getting a hold of a multimeter to do the tests. I had my battery tested at Auto Zone about 2 mos ago and they said the battery was fine, but now that I think of it, the guy testing didn't seem to know much about testing batteries diesels. Me being just as clueless, I might have easily been misinformed.

The black box you mentioned, is that the black box on the driver's side under the hood (engine) or inside the car?

Also, what did you have to do to fix your issue?

Thanks.

 

[wsad]

The black box under the hood. Since I just found this all out the other day, I haven't ...

The black box under the hood. Since I just found this all out the other day, I haven't done anything aside from remove that fuse. I never have heat but I have A/C, and after removing the fuse the A/C still works, so I don't know in what capacity this fuse is involved. I don't need any climate control now anyway, so I've just left it like that, and my battery hasn't drained since. I know that because testing my battery voltage before and after with a multimeter, I see that it doesn't drain down overnight anymore.

A thing I've learned with cars is that it's always good to have a battery charger and a multimeter. If you check on Ebay you can find one for as low as $1.00 + $5.00 shipping (mine was like that). If you buy one off Ebay, it's usually a yellow one, and possibly a CEN-TECH brand one that you can find cheap, and is perfect for any purpose. You'd think it'd be cheap quality-wise, but they're good. Just make sure when you buy one that it can measure at least:

-A/C voltage (e.g.-wall socket, etc.)
-D/C voltage (e.g.-car battery, batteries, etc.)
-Resistance (fuses, etc.)
-Current (current flow, etc.)

So, if you can, a multimeter, battery charger, and new battery would be good to have. HOWEVER, I wouldn't get a new battery until you figure out what's causing your battery to die. If it's just the fuse like in my case, or the battery's bad, then get a new one. I myself had been planning on getting a new battery since I figured this out, because I know that all the times my battery's died isn't good for it. So since the problem's solved, I can get a new battery and not have to worry about it being damaged from being drained down so much.

Glad to help in any capacity. Keep us all updated!

 

[d2e]

Hey wsad - The black box I looked at tonight has one big silver fuse in it. I might've lo...

Hey wsad - The black box I looked at tonight has one big silver fuse in it. I might've looked at the wrong one though... It's located under the hood, driver's side, kinda near the cruise control unit(?)

Also, I had the battery checked again and it was getting 9.3 amps and about 12.54 volts.

I looked at a few of the battery chargers at the auto store while there, but I didn't know if they would provide enough charge for these cars. If they will, I'll pick up one tomorrow.

I'll add that each time my battery has become drained, it's after trying to crank it and it not fully starting. My dash lights come on while I'm glowing and they stay on while I try cranking.

After so many tries in starting, you can hear the battery power slowly dying until the car finally won't make any noise, won't start and the dash lights go from dim to none.

I'll do more checking tomorrow. I'll take a cord with me to work as well just in case I can find an outlet around the building for the heater.

If not, I'll just try starting the car on each break and lunch, which is about 2 hours between each.

 

[wsad]

The black box you looked in was probably for the glow plug relay, with it's 50 or 80 amp...

The black box you looked in was probably for the glow plug relay, with it's 50 or 80 amp flat silver fuse. Is there a box on the driver's side under the hood on the hump above the wheel? On my 1980 there is, and if you open it there's two Bosch-like metal-cube relays and the fuse is in there with the relays, in the middle of a wire.

So, was the battery getting 12.54 volts when the car was running? If so, it should be around 13.8 volts. If it was only 12.54 then maybe something's up with the alternator or maybe bad cables are preventing the battery from getting the full approximately 13.8 volts when the car is running. You can get your alternator checked for free at AutoZone.

What you describe regarding the startup is exactly what happened to my car. I'd turn the key to "On" and the lights would all come up on the dash, and after it glowed I'd crank, but then it'd just crank, and then quickly slow down cranking until the battery just died. In my case it was because the battery didn't have enough voltage to begin with anyway.

Also, if you can get someone to test the current drain when the car's off like in my first post, that'll tell help you in troubleshooting.

 

[wdba123190]

What outside temps are we talking about here? My first 123 was a 79 wagon and she was t...

What outside temps are we talking about here? My first 123 was a 79 wagon and she was tough to start cold but not as bad as you descibe until it got down into the teens. When was the last time you changed your glow plugs or glow plug fuse? Or had the relay tested. Your problem could be a hard start problem, not a battery problem. Also did you get your valves adjusted recently. You will hear everyone here say that this is a must before every winter for cold starting and for the health, safety and longevity of your engine. Most say that it is as important as oil changes.
Your problem really sounds to me like a glow problem not just a battery problem, possibly both. If you're not sure the last time your car got plugs, put a new set in immediately and check the glow plug fuse (it is on the firewall directly behind the valve cover). That fuse would go several times a year in mine and I always had a couple spares in the glove box.
Good Luck and let me know if I can do anything for you. Keep us posted!
-M-

PS: I would also suggest going to your local MB dealer and paying the long dollar for the Mercedes battery. They designed for exactly what your car will put it through. Try to find the problem first though!

 

[d2e]

RE: Cold Weather & Draining Battery - What To Do?

Let's see if I can answer your questions...

"there a box on the driver's side under the hood on the hump above the wheel? On my 1980 there is, and if you open it there's two Bosch-like metal-cube relays and the fuse is in there with the relays, in the middle of a wire."

Yes, that's the box I was speaking of, above the hump of the wheel. Are these the fuses I need to pull and then test the battery?

When I had the battery tested 2 nights ago, that was at an AutoZone while the car was off. I didn't have them check the alternator, but I'll go back this evening to have that done. I'll also have the battery checked while the car is running.

"When was the last time you changed your glow plugs or glow plug fuse? Or had the relay tested. Also did you get your valves adjusted recently."

I upgraded to the fast-start Bosch glow plugs about 3 months ago; I had the relay replaced just a month ago. I have not had my valves adjusted at all nor have yet replaced that glow plug fuse. Should I have these both done and what kind of money is involved?

What outside temps are we talking about here?

The outside temps this week has been 30s & 40s.

In regards to getting a portable battery charger/booster, any particular brand and model recommended?

I luckily managed NOT to have the car battery drain on me yesterday only because I started it up and ran it for 5 min on each break and at lunch.

Does this help you both to further help me?

Thanks again guys...

 

[wsad]

RE: Cold Weather & Draining Battery - What To Do?

Ok, so in that relay box, don't do anything to the relays, those metal cubes. If there is one fuse in the middle of a wire (an inline fuse) then pull it out. Mine is a cylindrical glass fuse with silver metal ends. But the only way you're going to know if this helps or not is if you can get the guy or yourself to test the current between the negative battery cable and the negative battery post (when the neg. cable is disconnected from the battery and the car is off). Check to see how much current is being drained while the fuse is in, and then how much current is being drained after pulling out the fuse. If it significantly decreases after pulling the fuse, then you know that's what's draining your battery.

 

[wdba123190]

RE: Cold Weather & Draining Battery - What To Do?

Your car should absolutely start after no more than 5 secs of cranking at those temps. I think you're chasing the wrong thing. How long do you crank before you kill your battery? If you were really drain the battery when parked at work your battery would be dead after sitting all night whether you plugged it in or not. That will in no way charge the battery. If can start it in the AM it is not your battey it is a glow issue. I would immediately replace the fuse on the fire wall. I've chased that problem tons of time and that was the culprit 9 times out of 10. To find it just follow the wire off the last glow plug to the firewall and it should go right to a black box approx 3/4" wide 2 1/4" long and 1" deep. Under the black cover should be the fuse you are looking for. Replace that and if you're still having problems I would start checking voltage at the glow plugs. If you can start the car in the AM after it was plugged in it is not the battery. Period.
And I would absolutely adj the valves. If you are a DIYer you can do it pretty easily. I can outline it for you, but for great instruction and the wrenches that it much easier check out mercedessource.com. They have great kits that explain things clearly for the part-time DIYer. If you're not comfortable doing it yourself take it in somewhere. It shouldn't take anyone competant more than 30mins to do it and it should be quite affordable.
Hope this helps. Keep us updated!
-M-

 

[wsad]

RE: Cold Weather & Draining Battery - What To Do?

Yeah, and just take out the glow plug fuse and look at it and make sure it's solid, and doesn't have a hairline crack or something. It's just that flat strip of silver metal that's screwed in the glow plug relay box.

 

[d2e]

RE: Cold Weather & Draining Battery - What To Do?

Let me just say, you guys are great and I can't wait to check your replies of help. That's what makes this forum a gem!

I went back to AutoZone tonight and had them remove the battery and test it on the more accurate (in-store) tester. It showed my battery was bad and needs replacing.

However, before having it tested inside, someone tested it again with the portable tester outside first and it showed my battery in perfect condition. (While the car was running, battery tested 13.63V, 1.5A and climbing; while the car was off, battery tested 11.5V, 1.1A and climbing).

My Interstate battery is still under warranty, but, since I don't have an original receipt of purchase, Interstate will not let me "claim" that warranty. I called and asked their Cust Service dept earlier today.

I will be replacing my glow plug fuse, and I know exactly where this is and how to do it. I assume I can buy this fuse at any parts store? Still bothers me why my mechanic wouldn't replace this EVEN after I suggested it. He thinks the glow problem is related to a bad ignition switch.

Per the suggestion, I'll schedule to get the valves adjusted within the next 1-2 weeks since that's something that should be done. Being a lady, I sometimes think that I don't need to go digging around in things. []

I again had to get another jump today at work, although I started my car up with no problem about 2 hours prior to the battery going dead again.

I'll also mention that my car has never quick-started since I've had it (July '03). But, once I upgraded to the Bosch glow plugs, it doesn't take as long to glow like it did with the old styled plugs (about a min or so vs. 3-4 min and as much as 20 min to glow and start.) That was awful of course, which forced the plug upgrade.

Even though the glow time is short (when it's not having the glow problem), the car still takes a few tries to start it, whether it has sat 10 minutes or 10 hours. It'll make the sound like it's starting but won't always turn over the first time.

Question - I'm still calling around for this Interstate Battery (model MB88-60 or MT-49). Should I look into any other battery brands good for these cars, or is Interstate the only brand to buy?

Appreciate the help again everyone.

 

[wdba123190]

RE: Cold Weather & Draining Battery - What To Do?

... Just thinking ... I had a problem not entirely dis-similar to this with a friends w123 that is starting to come back to me (really no pun intended). He had a starting problem and after chasing it all over the car it turned out to be a short in the starter itself. This would only allow the starter to spin at approx half the rev it needed, thus draining the battery fast and making the car start hard... Just a thought... you may want to have the starter tested next time you have the car in for a service.
"Even though the glow time is short (when it's not having the glow problem), the car still takes a few tries to start it, whether it has sat 10 minutes or 10 hours. It'll make the sound like it's starting but won't always turn over the first time."
This bothers me a little. One of the things that makes me wonder if your starter is cranking hard enough. But we start getting into the area of "it could be anything". One very likely culprit would be bad compression in one or more cylinders. How many miles do you have on her? Diesels are compression ignition and if you have poor compression your car is going to start really hard and have little power on the road. A w123 with excellent compression should start (over 40*F) WITHOUT glowing the plugs after cranking for a less than a minute. You might want to get the compression tested at next service.
Another thing I would ask would be to take off your air filter cover and run your finger on the metal bottom inside the circular filter. How much oil do you have there? Is it a very light film or is it very wet? Was the car sitting for very long before you purchased it? Where do you get your diesel fuel? If you have not done so change both fuel filters and even if you have if the car was sitting for a while befor it found you change them again. You could have plugged filter or bad fuel. Immediately go to Autozone and get a bottle of what I call "diesel food". I believe there is only one brand of diesel cetane booster at the zone, get the grey/silver bottle. Put the whole damn thing in and run it.
Wow, this is a long post...
In summary: Get the valves adjusted. This could solve all the problem (and I would be praying that it does)! It really would be a good idea to get the compression tested when the valves are adjusted (if your comp is below about 225lbs you are basically SOL and looking at rebuilding the engine...). This will just let you know where you stand. Run diesel food through and change BOTH fuel filters. If you still have problems after these fixes get the starter tested and replaced if it is bad. And on the subject of batteries I would recomend an MB battery from the dealer.
I hope that's not too much to swallow all at once and I hope it does you some good! Keep me posted.
-M-

 

[wsad]

RE: Cold Weather & Draining Battery - What To Do?

Yes, and you can also get your starter tested for free at AutoZone.

 

[d2e]

RE: Cold Weather & Draining Battery - What To Do?

Guys, thanks again for your help and information. I will follow up with the suggestions on Monday when I can get to a MB mechanic.

As if this couldn't get more annoying and confusing, I spotted a replacement Interstate battery today.

The Tire service center with the battery performed an electrical test on the vehicle first before replacing the battery.

Here are the printed results of that test:

Battery Test
Rating: 750 CCA
Results: Good Battery, 12.80V, 742CCA

Battery Good to:
0 degrees F

Battery Age is Approx.:
40 months

Starter Test
(I didn't quite know how to interpret this)
Cranking - Normal Chart
10.53V, 3.07s

Charging System
Results: No Problems
14.80V No Load
13.71V Loads

After getting these results, the center then performed the negative battery cable test (where the cable is removed, as mentioned in an earlier reply from someone) and saw that something IS draining the battery. There was a little light that glowed in this needle-like tester. The light would glow very bright, then go to very dim. This test was done with the car off. We once removed the trunk light but that didn't help, as the light still was very bright at first, going to very dim.

Also, my alternator belt is very worn and needs replacing. Furthermore, my battery cables have corrosion. The service guy took off some of the hosing for the positive cable and the more he removed the more corrosion we saw.

Needless to say, because there were a few things at play here, they didn't feel that I needed a new battery. They told me to take it to an MB specialist and determine the problem.

I plan to be in Charlotte after work tonight.

Can anyone recommend an affordable MB mechanic in Charlotte that I can visit on Monday morning?

Thanks,

d2e

 

[wsad]

RE: Cold Weather & Draining Battery - What To Do?

So, like I said earlier, you need to get that electrical drain troubleshooted and then taken care of. Then you MUST get the battery cables replaced. If you remember, that was the one of the first things (if not the first) thing I said that could be causing your problem (I think it may have been in your other post regarding this problem). Bad cables will make it very hard to start your car, and that drain will suck the life out of your battery and make starting even harder. I know because I've been through all of this before.

So far the situation is looking better, as it only seems to be a drain and bad cables causing your problem!

So do you know if you have a fuse in the relay box?

 

[wdba123190]

RE: Cold Weather & Draining Battery - What To Do?

Good Lord, I hope you get off that Lucky!! That would be sweet!
I would still recommend running diesel food every tank for the length of the winter, just follow the instructions on the can. And get those valves adjusted!
-M-

 

[d2e]

RE: Cold Weather & Draining Battery - What To Do?

Hello again guys...

wsad - I don't see a fuse in the relay box, unless the fuse is the large, metal block inside that black box.

wdba - I've seen the diesel product at AutoZone before and will pick up some today.

Let me just mention, my car has been at the mechanic all this morning. My mechanic is still convinced that my problem is either the cold weather (more likely) or the battery. He has not found the drain as of yet and says that this issue with hard starting during cold weather is common. His advice - let it glow longer and more than once, as well as plug it up while away from home. Even though the car is 25 yo, it seems to me that this shouldn't be required unless I was living in a MUCH colder state during the winter.

He also said too that the draining battery problem should happen when I have it plugged to my block heater while at home, just as it does when it's not plugged in while at work.

What's strange though is that this drain does NOT happen when I try starting the car after it has been plugged with the block heater for hours.

Would turning the "idle" key cause or help this starting problem? It's the key that's to the left of the steering wheel. It has been moved from the position it used to sit in, but that was a few weeks ago when I noticed it. I thought to mention it.

Thanks...

 

[wsad]

RE: Cold Weather & Draining Battery - What To Do?

Ok, if you can get that drain found, that would be good. Basically it's draining your battery whenever the car is off.

Otherwise AT LEAST get the cables replaced if they are corroded at all. It won't cost you much at all. If your mechanic can't hook you up with some, try going to NAPA. If you bug them enough, they have the cable and the cable ends, and will make them for you. When winter rolled around one year, I had the same problem, except my car wouldn't start at all. Replaced the bad cables and started up like a dream.

Your instincts are right in regards to the mechanic's comments. You shouldn't have to go around plugging in your car wherever you go. Don't accept that.

Basically what's happening when you have the car plugged in is that it's just make starting easier. That's it. That's why you can start it after plugging it in. Otherwise, with the drain, bad cables, and the cold, starting is very hard.

Regarding the idle knob, maybe one of your mechanic's adjusted it to try to make starting easier.

 

[d2e]

RE: Cold Weather & Draining Battery - What To Do?

wsad,

Thanks for the advice and follow up. My plan is to take it to another mechanic for addt'l help on tomorrow.

About changing the fuel filters:

I tried changing both fuel filters tonight, and bought some Diesel Fuel Supplement from Advance Auto.

I managed to get the plastic fuel filter off & changed with no problem. This is the one I changed first.

Now I can't get the metal filter off and I don't know which I should turn it! I've tried clockwise and counterclockwise. Seems to turn most counterclockwise but boy is it difficult to come off and I'm using an oil filter wrench.

Can anyone advise me which way to turn the metal fuel filter? Could there be a lot of pressure preventing it from coming off easily because I changed the plastic filter first? (Btw, I just read on another post about using cheap fuel filters. I'll be getting a better filter for these diesels on tomorrow if it can be found and take the Purolator back tonight. Glad I read that tip!)

Also, I thought I could find the glow fuse at the store but have not yet found it. Where else should I try?

wsad, the two silver relays under the black box on the hump of the wheel - are those the ones you said I should try removing?