[MurSayDeez]

Okay, I have encountered the most unusual electrical issue ever in a car that I have owned. I am hoping for some advice.

The front window fuse blows every time I replace it.

When I turn the car on, the car buzzes extremely loud, but as soon as I step on the brake, it stops.

When I crank the car and turn the heat on, the ABS light kicks on for 5-10 seconds and then kicks off

When I turn the heat on, the car begins to idle rough, and only blows heat out of the 2 side vents, not out of the center.

I have not noticed any grounds loose or corroded, so I am lost at this moment. I figured I would try here before I start pulling out the fuse box, and disassembling the interior.

Thanks in advance.

 

[Real1shepherd]

Okay, I have encountered the most unusual electrical issue ever in a car that I have owned. I am hoping for some advice.

The front window fuse blows every time I replace it.

When I turn the car on, the car buzzes extremely loud, but as soon as I step on the brake, it stops.

When I crank the car and turn the heat on, the ABS light kicks on for 5-10 seconds and then kicks off

When I turn the heat on, the car begins to idle rough, and only blows heat out of the 2 side vents, not out of the center.

I have not noticed any grounds loose or corroded, so I am lost at this moment. I figured I would try here before I start pulling out the fuse box, and disassembling the interior.

Thanks in advance.

It's a ground fault issue, unless your alternator reg is bad. With the engine running at idle, test what voltages you get across your battery terminals. Always suspect a bad OVP for electric weirdness, but this sounds like ground shorts somewhere. Oh and BTW, heat only comes out the side vents and down towards your feet...not through the center vents.

Kevin

 

[Jayare]

A few things. A) What year W124? Has the car always had these problems? Warm air isn't supposed to come out of the center vent... only side vents, floor and rear floor. Which window blows the fuse? If it's the driver door, look into the harness from body to door for a broken ground (brn wire).

What voltage are you getting at the battery with the car running? Have your replaced all the fuses with the newer copper core type?

Report back,

Jayare

 

[Jayare]

Thinking the same things are we Kevin....

Jim

 

[Real1shepherd]

Thinking the same things are we Kevin....

Jim

Yes indeed... And some history is everything.:thumbsup:

Kevin

 

[MurSayDeez]

1. Some fuses have been replaced with copper.
2. Battery reading is 13.8 with engine on.
3. I removed the following grounds today, cleaned, and retightened:
The two near battery, the one near passenger headlight, the one near driver headlight, the one under ignition coil, the one from tranny to frame underneath car.
4. The vehicle is an 89 300e. I do not know much past history, just purchased around 3 weeks ago, and I am still working out kinks.

I imagine there are alot more grounds, so help in location would be greatly appreciated.

Also, I checked the switches today for windows, they were good. I also checked the fuse box, all was good. I did get my front driver window working. The motor had ending up rusting up, so once I cleaned it up, it began to work. But the passenger front and driver rear still do not work.

BTW the ABS no longer comes on with the heat either.

And thanks for the info on the heat not coming out of center vents...I was thinking I was crazy, lol.

 

[Kajtek1]

I would guess the car was parked for long time before you purchased it?
ABS light comes with low voltage, not necessary with traction problems.
That would explain why it was staying for some time after start up and come when you turn the blower on. Blower takes pretty good current, so it could lower the voltage on idle to the level where ABS sends the warning.
With some exercise the blower started to run easier and the problems did stop.
I would keep the eye on voltage as the alternator brushes might be wear out.

 

[stormtigers]

It's a ground fault issue, unless your alternator reg is bad. With the engine running at idle, test what voltages you get across your battery terminals. Always suspect a bad OVP for electric weirdness, but this sounds like ground shorts somewhere. Oh and BTW, heat only comes out the side vents and down towards your feet...not through the center vents.

Kevin

Hey Numb Bum
Did you fix the buttmobile up to do the same thing ?
The center vents are pumping out green smokey cold air

Tight-Ass

 

[Sam Fuller]

It's a ground fault issue, unless your alternator reg is bad. With the engine running at idle, test what voltages you get across your battery terminals. Always suspect a bad OVP for electric weirdness, but this sounds like ground shorts somewhere. Oh and BTW, heat only comes out the side vents and down towards your feet...not through the center vents.

Kevin

I just tested mine today 13.65 volts at idle.

 

[stormtigers]

1. Some fuses have been replaced with copper.
2. Battery reading is 13.8 with engine on.
3. I removed the following grounds today, cleaned, and retightened:
The two near battery, the one near passenger headlight, the one near driver headlight, the one under ignition coil, the one from tranny to frame underneath car.
4. The vehicle is an 89 300e. I do not know much past history, just purchased around 3 weeks ago, and I am still working out kinks.

I imagine there are alot more grounds, so help in location would be greatly appreciated.

Also, I checked the switches today for windows, they were good. I also checked the fuse box, all was good. I did get my front driver window working. The motor had ending up rusting up, so once I cleaned it up, it began to work. But the passenger front and driver rear still do not work.

BTW the ABS no longer comes on with the heat either.

And thanks for the info on the heat not coming out of center vents...I was thinking I was crazy, lol.

1. Replace ALL fuses with Copper ASAP !
The aluminium ones look intact but I found some that were cracked almost all the way through but looked fine at first glance.

2. Some of your symptoms sound like OVP issue.
The OVP is over next to the battery beside one of the relay. Weird ass thing with 1 or 2 fuses on top of it. Don't buy a cheap replacement get a brand one (cheap ones have a habit of creating other problems.)
http://www.benzworld.org/forums/w124-e-ce-d-td-class/1633436-ovp-relay-change-1988-300ce-pictorial.html

3. Failing the two above I would lean towards Voltage Regulator (at the back of the alternator)
http://www.benzworld.org/forums/w124-e-ce-d-td-class/1678395-new-video-kent.html

 

[Sam Fuller]

1. Replace ALL fuses with Copper ASAP !
The aluminium ones look intact but I found some that were cracked almost all the way through but looked fine at first glance.

2. Some of your symptoms sound like OVP issue.
The OVP is over next to the battery beside one of the relay. Weird ass thing with 1 or 2 fuses on top of it. Don't buy a cheap replacement get a brand one (cheap ones have a habit of creating other problems.)
http://www.benzworld.org/forums/w124-e-ce-d-td-class/1633436-ovp-relay-change-1988-300ce-pictorial.html

3. Failing the two above I would lean towards Voltage Regulator (at the back of the alternator)
http://www.benzworld.org/forums/w124-e-ce-d-td-class/1678395-new-video-kent.html

look at this . It might help Mercedes 190E Rough Start Problem Solved | MercedesSource.com

 

[chuckh0308]

Where did you get your copper fuses? I bought some off Amazon that "appeared" to be copper and were advertised as ceramic bodied, and they were plastic with who knows what kind of copper colored metal. I started having the front window fuse blow as soon as I put those in. Then I ordered good copper fuses from Mercedes Source and haven't had a blown fuse since.

 

[Real1shepherd]

Hey Numb Bum
Did you fix the buttmobile up to do the same thing ?
The center vents are pumping out green smokey cold air

Tight-Ass

Dear Tight-Ass
Oh and I suppose now you don't like the green smoke?? During the last round of Who-Hit-John, you were all for it, as I recall.

Numb Bum

 

[Real1shepherd]

look at this . It might help Mercedes 190E Rough Start Problem Solved | MercedesSource.com

This is soooo easy if you suspect charging gremlins; put a voltage meter across the battery while idling. Look for a consistent 13.8 volts but less than 14.1(overcharging this high or higher). Come on Kent...you shoulda tested that at the beginning....especially when a voltage reg stranded you before!

Kevin