Glow Light Staying On - Now Battery Dead - Page 2 - PeachParts Mercedes-Benz Forum

Brian Carlton · #16 10-30-2004, 05:07 PM

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PatrickW · #17 10-30-2004, 07:41 PM

Quote:

Originally Posted by Palangi

My gut feeling is 90% chance its the glow plug relay, 10% chance its the ignition switch. You will need to catch it in the act with the voltmeter to confirm.

I have started carrying my voltmeter in the car with me, so I can try to catch it.

Also, I had kept the instruction manual for my voltmeter, so I think I know how to use it as an ammeter if I need to.

I also drove the car for a while, and then later rechecked each cell of the battery with my $3 hydrometer. One cell tested at 25%, two others at 50%, and the rest were at 75%.

So here's my plan:

1) I'll buy a new battery, since cold weather is coming up. I think it's a 1997 battery the more I think about it.

2) I'll use my voltmeter as an ammeter to see if there's any current draw when the engine is off. Perhaps by doing that and pulling a fuse one at a time it will allow me to find any current leaks, if there are any.

3) I'll buy a new Glow Plug Relay, but not install it yet. I'll continue carrying my voltmeter around and try to catch it happening, so that I'll know for sure exactly what the problem is.

4) I'll consider buying new Glow Plugs while I'm at it. With cold weather coming up, I wouldn't want to be stranded out of town (I don't plan on driving the car in the winter after the snow falls, because I don't want to get any salt in it).

Thoughts...?

Thanks!

- Patrick

Palangi · #18 10-30-2004, 08:34 PM

No sense putting in new glow plugs until you resolve the problem of the plugs staying on, although it might be prudent to do a quick resistance check of each plug to see if any are totaly burned out. Seems like you know your way around a meter. Do you know how to isolate the plugs for a resistance measurement? If not, we will guide you through it.

boneheaddoctor · #19 10-30-2004, 08:55 PM

be careful using a Multimeter as an ammeter. Few of them can take more than a few amps. At best you blow a fuse at worst with a cheap meter you render it junk.

MTUpower · #20 10-30-2004, 10:00 PM

Here's the deal with the gow plug light on the dash and why your battery is dead. If the light flashes, you either have at least one bad glow plug (perhaps more than one) or a bad relay. More than likely it's a bad plug. If the light stays on, your engine is providing power to the glow plugs and yes it is 80 amps- much more than the alternator can provide, so the battery tries to take up the slack and thus it drains your battery. This is caused by a bad relay most often, but could be ground somewhere in the glow plug wiring. Testing the plugs is not difficult. Go to the junk yard and get another relay, or ask a member that has the resources of a yard to get one for you- check the parts forum. I could find one and ship it to you for less than $30, but there are new sellers and other parts hounds that you can access also. My indie told me all about the glow plug stuff, and the new SD I bought had the light come on while I was driving for a a minute- I pulled over- shut her down and restarted- no light.

Brian Carlton · #21 10-31-2004, 01:51 AM

Quote:

Originally Posted by PatrickW

So here's my plan:

1) I'll buy a new battery, since cold weather is coming up. I think it's a 1997 battery the more I think about it.

2) I'll use my voltmeter as an ammeter to see if there's any current draw when the engine is off. Perhaps by doing that and pulling a fuse one at a time it will allow me to find any current leaks, if there are any.

3) I'll buy a new Glow Plug Relay, but not install it yet. I'll continue carrying my voltmeter around and try to catch it happening, so that I'll know for sure exactly what the problem is.

4) I'll consider buying new Glow Plugs while I'm at it. With cold weather coming up, I wouldn't want to be stranded out of town (I don't plan on driving the car in the winter after the snow falls, because I don't want to get any salt in it).

Thoughts...?

1) You are way overdue for a new battery. Get it now. Autozone makes a decent battery for a good price.

2) Just check to see what the current draw is with the ammeter before doing anything. As stated by others, make sure that everything is off and the doors are closed prior to the test, because the meter cannot take much current. If the test shows less than 60 ma, you are probably fine. If it shows more than this value, now you can start pulling fuses to see which circuit has the leak.

3) William (MTU Power) can set you up with a decent used one for a fraction of new.

4) You can consider it, but you probably don't need them. Check the resistance of each glow plug with a very sensitive ohmmeter. They should all be below 1 ohm.

psfred · #22 10-31-2004, 02:11 PM

The bearings in the alternator will make plenty of noise (high pitched howl or squeal) when they go bad.

I'd say you definitely have a bad glow plug relay or a loose connection from the ignition switch (or possibly a bad ignition switch that keeps triggering the glow plug relay) - the glow plugs will drain the battery with the headlights on.

shake the relay -- if it rattles, replace it, the contacts have broken and are shorting it out. This happened on the Volvo, I'd just been bragging about how well it ran and how dependable it was when the voltage started to drop coming home from a trip -- first the cruise control dropped out, then the windows got slow, then the headlights started to dim out -- I was looking for a place to pull over while driving as fast as I dared to get to the next town where a buddy lived when I hit a bump and "pop" - - full voltage. Next time I started it, I pulled the plug to the relay, and the headlights brightened up -- plugged it back in, they dimmed even though the relay didn't click.

New relay fixed it, to the tune of $175!

Peter

MTUpower · #23 10-31-2004, 04:41 PM

Peter-
need other volvo parts? the yards here are not MB exclusive

psfred · #24 10-31-2004, 07:04 PM

A good injection pump off a D24T would be VERY nice!

Must be from the turbo model!

Peter

PatrickW · #25 11-12-2004, 09:01 PM

I wanted to post my resolution to this problem. Perhaps someone in the future will benefit.

The Glow Plug Relay was bad.

After replacing it with a new one, I took apart my failed one. It had about half an inch of water in it, which I presume was intermitantly shorting out internal connections. The water probably got in there when I degreased and rinsed the engine on the day I'd bought the car.

I also replaced the battery with a Sears Die Hard.

This morning it was 14 degrees (F) outside. I'd left my MB parked outside so I could try to start it when very cold. If I'm going to have problems starting my car, I want it to happen in my own driveway in the morning - not at work 40 miles away and after sunset.

It started immediatley.

I hope this info helps someone.

- Patrick

PS - my car is in good shape, and I don't intend on driving it after the snow falls. I'm going to take good care of this one!

boneheaddoctor · #26 11-12-2004, 09:55 PM

Glad you found the problem.

ayalar007 · #27 11-13-2004, 11:39 AM

Patrick,

I'm glad you solved the problem, and probably prevented one for me too. I was planning on rinsing the engine with degreaser this weekend, Now I know to wrap it in palstic before I give the old hose down!

Thanks!