83 300d Will Not Start (Electrical Problem) - PeachParts Mercedes-Benz Forum

Boardmonger · #1 09-30-2006, 01:01 AM

Alright so this morning I woke up to go to school and got in turbo (83 300d turbo) as usual and turned the key, glow light went out and tried to crank it over and it just clicked as if the battery were dead. I tried again and something was clicking, the lights and radio weren't working and the tach started jumping. This all lasted about 5 seconds or so. I got home from school and started investigating and traced the clicking to the glow plug relay. It appears when you turn the key the tach jumps and lights dim for about 5 or so seconds untill they go out, which is generally the length before my glow plug light goes out. The starter won't even engage making me think the battery is dead. All fuses are fine and there are no visible open wires.

So I am thinking I have a bad glow plug relay or a short somewhere between that and the ignition. I am not sure if anyone has experienced anything like this but the car was working fine the days prior. No dim lights or anything like that. I've never had any electrical issues so I find it pretty strange that all of the sudden it simply isn't working. Would a glow plug relay go bad like this so quick or is it something else? Any help is appreciated because I don't like driving my parents gas guzzling landcruiser. Thanks.

Jeremy5848 · #2 09-30-2006, 02:10 AM

Without turning the key switch, try turning on the headlights. If they are dim or not working, you can pretty much conclude that the battery is very weak, if not dead. Try to confirm this with a voltmeter on the battery terminals. How about the radio and other accessories? Do they work or not? Repost when you have made these tests.

How old is the battery? Did you leave some lights on last time you drove the car? Seems to me someone here wrote about a glow plug problem in which the relay froze in the closed position and the glow plugs never turned off. The concern was that the glow plugs might burn out; I don't remember if the glow plugs stayed on after the key switch was turned off.

Boardmonger · #3 09-30-2006, 02:37 AM

The windows work fine, the lights will turn on but it is delayed like 15 seconds from turning on the switch. Same goes for the radio. The cabin light fluctuates from normal to dimmed and when you turn on the hazards they work but are dim and as they flash the cabin light dims as well. I am going to try to jump the car tomorrow if I can maneuver the blue car around it and I'll get back to you. No lights or accesories were left on, that is why I find it so strange that the battery died so suddenly. I've never had trouble starting the car or running accessories (all stock in that manner). The thing that confuses me is the clicking clearly coming from that glow plug relay.

#4 09-30-2006, 07:21 AM

I just sounds like a dead battery to me, either due to the battery or due to a problem with the charging system. It's not that unusual for batteries to die without warning. The GP relay is probably just clicking because it's not getting sufficient voltage (due to the dead battery). Does the car start normally if you jump it? What is the voltage reading on the battery (both running and not)?

Brian Carlton · #5 09-30-2006, 09:12 AM

Quote:

Originally Posted by Boardmonger

No lights or accesories were left on, that is why I find it so strange that the battery died so suddenly. I've never had trouble starting the car or running accessories (all stock in that manner).

LOL........the battery has not "died without warning".

It's still powering the lights and accessories and simply won't turn the starter.

I believe that it's providing quite a good warning.......

I'd jump start it and then be sure the alternator is working properly (more than 13.4 volts). If so, then drive it and see if the problem recurs. If it does, then replace the battery.

If you want guaranteed reliablility, then replace the battery as soon as you confirm proper output voltage from the alternator.