Glow plugs? Please help.....

I was having problems with my charging system, and thanks to advice from some people in Tech Help, I'm pretty sure that problem was solved with the replacement of my voltage regulator. But since the new one has been put in, the battery light comes on when the car is off (not when it's on) and the glow pug light doesn't come on ever. The car has trouble starting up unless I push on the gas, but it starts no problem after it's been driving, stopped, and started again. I have no idea where to look for the glow plugs, or what exactly I'd be looking for. Another thing... the battery was connected backwards yesterday (pos on neg) before the v.r. change. That may have something to do with it, but everything else works fine. I'm in the process of doing a search for glow plugs, but any advice would be greatly appreciated. And, besides really wanting to know and understand how my car works, I can't afford a mechanic right now.

It's an 84 190D.

[MBenzNL]

If the glow plug light doesn't come on and the car starts anyway (although with some difficulties) you have a dead glow plug.
Open the hood and take off the cap ofthe glow relay (it is mounted on the right side of the engine ebay when you are standing in front of the car). Unplug the connector and take an ohm-meter to check the resistance of the pins. The glow plug that is dead should give a complete different reading.
If you do not have an ohm-meter, you can connect a wire to the battery plus and push the other end of the wire to the pins (one after one). The glow plugs that are still good should give some sparks when you connect the powered wire to the pin and the pin that leads to the dead glow plug doesn't react at all...

It is possible that the fuse in the glow relay is blown by the inverse connected battery, but since the car is still starting, I do not think that is the problem...

greetingz,

Hi Elbow,
Just another piece of advice is that you may want to consider looking at the FASTLANE website here and look at the new Bosch glow plugs they have for sale. I think they are $120.00 and supposedly outperform the older ones you most likely have. My aunt changed hers not that long ago before passing the car onto me when the light wasn't coming on... although the car worked fine. But I am thinking about changing mine to the new and improved ones just because of the benefits. I don't know how to install them... but maybe they come with directions.

SB

['79 Super Turtle]

Or, if you want to spend less money, you could install the original Bosch glow plugs for $9.00 a piece. The part number is: 000 159 83 01

Thanks for responding..... I opened the cover and the relay is fine, and I'm going to check the plugs, but can somebody give me a little more information? Theres the relay and then two more black plugs, one with a few colored wires covered with a black cover holding them together and then one with just a large black cover. Which is the one that I check? And how likely is it that I will get electricuted?

[dieseldan]

If the motor is off you, will not be shocked. Buit you may get a little dirty. The more I work on my car, the smarter I get. Dan

[longston]

Lisa,

For repairs and troubleshooting, it's always better to start simple, and work up to complicated. Your car is DC, not AC, and won't electrocute you. Your glow plugs are in a row on the side of the motor, and will look sort of like sparkplugs, just without the "boots" over them. BTW, does your in dash clock still work? Did it work before the battery was hooked up backwards? I ask because you may have damaged it by the polarity swap. That leads to my next question.

Have you found and checked the GlowPlug Fuse? You may have blown it when the battery was hooked up backwards. In my car (whole different car & chassis), the fuse is in a small black rectangle on my left (drivers) front fender, and it a whole lot larger than a regular one!.

You say your battery light comes on when the car is off. Can we assume that you mean with the key in the on position, and the engine off, but not with the key in the off position? If so, that's perfectly normal, the light comes on as a bulb test when the switch is on, and goes off when the engine is running, unless there is a problem with the charging system. But, do you have the right battery for your car? Diesels need larger and more powerful batteries than the gasoline motors use.

And I wouldn't think that you need to have the "upgrade" $120.00 glow plug system, unless you plan on visiting the Canadian tundra real soon. Yours should start with the less expensive ones even in the mountains in New Mexico during the winter.

['79 Super Turtle]

Scott, I think her light is on while she is in the house. Right? I have heard of this before. I am furiously racking my brain for the memory. I think the Voltage Regulator or battery are still hooked up backwards or a fuse is blown somewhere.
Patsy

I checked the fuse, and my guess would be that if it was broken or bent, it would be blown, but it looks fine. I tried to find the glow plugs, but I thought I had read in a search that they were in the same box as the fuse, but I just realized that I misinterpreted... I think. Those are the relays? I'll go look for the plugs now. My dash clock works fine, and it worked before the battery swap as well.
My battery light... I mean that it goes on when the car is actually off, with the key out...
Thank you for having patience with me, and thanks for the tip about the electricity. I never thought about the AC/DC thing.

[MBenzNL]

The glow relay is mounted above the left front wheel (whilst standing in front of the car you will see it at your right hand). It is a black box 15x6cm or something like that. You can take off the entire lid and you will see the glow-fuse in there (not in the regular fuse box).

The glow plugs are in your engines' head. There is nothing glow-related to be found in the regular fuse-box.

If the glow plug light doesn't come on and the car starts anyway (although with some difficulties) you have a dead glow plug.
Open the hood and take off the cap ofthe glow relay (it is mounted on the right side of the engine ebay when you are standing in front of the car). Unplug the connector and take an ohm-meter to check the resistance of the pins. The glow plug that is dead should give a complete different reading.
If you do not have an ohm-meter, you can connect a wire to the battery plus and push the other end of the wire to the pins (one after one). The glow plugs that are still good should give some sparks when you connect the powered wire to the pin and the pin that leads to the dead glow plug doesn't react at all...

greetingz,

['79 Super Turtle]

I have a few questions, comments.

Firstly, why was the battery hooked up backwards, for how long, and is it correct now for sure? Does the negative cable run to the chassis ground or the starter?

Secondly, is the voltage regulator an internal regulator which slips into the back of the alternator or is it mounted externally? Who installed it? Is it the correct voltage regulator? Was the alternator tested? Are the wires for the voltage regulator hooked up correctly?

Thirdly, if it is very cold where you live it would not be that abnormal to have to give the car gas when you first start it.

Before looking at the glow plugs I would track down why the battery light is on when the car is off. Seems to me that something is hooked up wrong, or a ground, or fuse is bad.

Patsy

[longston]

Well, I went back to your post in Tech Help, and Benzmac already told you what the problem was. You have a bad diode in your alternator. Wolfgang, mein local Mercedes expert agrees with Donnie that you have a bad diode in the alternator.

The simple test is to (with the ignition OFF) carefully unplug the alternator wires and see if the light goes out. But be sure not to touch the wires to anything when you do it. If the light goes out, you need a new diode, or diodes in your alternator. You may find an auto electric shop that can do it for you, or you may have to spring for a whole alternator. FastLane (here) has rebuilt ones for $116.80 + $40.00 Core charge = $156.80, Part # 13056. The Mercedes part # is: 007-154-54-02.

You will need to take it somewhere to have the whole charging system tested. Many shops can and will test it in the car.

Thank you everyone... I did that test and the light did go out, so I'm going to call around tomorrow and see how I can get it repaired. I'm thinking that maybe I don't even have a problem with my glow plugs, maybe it's just all tied into the charging problem, but I guess I'll just have to wait and see...
I was looking up some things about the battery light staying on, and the diodes were one of the things that would cause that, but a couple other things were mentioned, and I would like to know if anyone had any other suggestions for me before I get the diodes repaired or buy a new alternator.
To what you asked Pasty, the battery was hooked up backwards just for a second, it sparked and then we realized, but it is for sure correct now. The negative cable runs to the ground. The voltage regulator is internal, and I installed it. There were no wires, just two screws. I'm pretty sure it's the correct v.r., I asked at the shop to look it up on their computer. I had the alternator tested with the old voltage regulator in it at three different places, and two got no reading at all and the other said it was 11.5...

[rickjordan]

This is so strange. I just got off the phone with my father, and he is having the same glow plug problem. First thing in the morning, in VA, the engine take forever to kick over and his glow plug light is not coming on. The car works fine and starts fine for the rest of the day, but first thing in the morning she will not easily kick over with out using the block heater to create some heat. This leads me to believe either his glowplug relay or as it has been said here, a bad glowplug. So any info in this area would be helpful to me as well.

Take your car to Autozone or Advanced Auto Parts. They will check your alternator/battery/charging system for free. They will sell you a battery to fit your car for about $65,and install it free. If you need the alternator, they will sell you one for $100. They will not install the alternator, but will give you a life time warranty good at any of their stores. You don't even need keep the receipt. The sale is kept in their computer system.
Bill Lewallen Lexington,Ky. The Bluegrass State where the grass is really green, and we use the Green coolant.