Mercedes-Benz Forum banner

1 - 9 of 9 Posts

·
Registered
1980 300D, 1985 300TD
Joined
·
11 Posts
Discussion Starter · #1 ·
Hi experts:

I have a 85 300 DT that is having difficulty starting. After I let the glow plugs warm, I turn the ignition and get a "click" sound. I assume that it is the battery, but here is the weird thing; If I try to start it a few more times, it will start. It can take as little as 2 or as many as 10 ignition sequences before it will turn over. Whenever it turns over it starts. At rest it is over 12V, but barely. When we try to start (on the unsuccessful tries) it drops a little; maybe below 12v. After it is running it pops back above 13v; which makes me think that the alternator is fine. I have not changed the battery in the 2 years we have owned the car.

Any suggestions?

Kevin
 

·
Registered
1959 220S cabriolet, 1983 240D original owner, 1999 E300 turbo diesel, 1988 560SL, 2003 SLK320
Joined
·
3,513 Posts
Sounds like you've got a starter/solenoid issue. How old is the battery? There is a date code on it. If more than five years, it's probably wise to replace it. You can check the glow plugs, but if all you get is a click, that's not a sign of a glow plug problem. Good plugs measure about 0.7 ohms cold.

Len
 

·
Registered
'82 300D
Joined
·
1,279 Posts
Also check the Neutral Safety Switch. I would check that battery as advised as well as the starter. 13v BTW is a bit low. You should be getting 14.1-14.5 volts for charging.

Have the battery and the aslt load tested.
 

·
Registered
83 300CD, 07 ML320 CDI, 04 WRX, 86 300D (totalled by my neighbor), 85 300D (sold)
Joined
·
876 Posts
Are there any warning lights on after it starts ? It may also be a charging problem. Mine was like that - the previous owner thought it was a bad starter. It turned out to be a bad alternator.
 

·
Registered
1984 300CD
Joined
·
2,700 Posts
This is an issue I've had with the two coupes I've owned more than any other. On my black CD I changed three starters that acted this way. Now it's started on my Blue/Green CD. Funny thing though, it will crank just fine jumping the posts 30 & 50 on the cable connector on the right fender well (so far). Other times it will work just fine. It IS a bit of an embarrassment having to pop the hood to start it some times. Oh well, I do have a lot of experience changing starters though. LOL
 

·
Registered
money pits of various forms
Joined
·
5,885 Posts
Make sure all your terminals are clean. In winter this is quite common as the solenoid grease will gunk it up and prevent it from moving freely. Its entirely possible that it is dirty.

Try jumping the terminals as suggested, this will help eliminate weak contacts in the ignition switch.

More than likely after 2 years its just time for a new starter/solenoid.
 
1 - 9 of 9 Posts
Top