Glow Plug Relay(s) question
 

83 240D Wondered if anyone could tell me how many components are involved with the glow plug system? Most discussions/videos, I've seen, point to the unit on the front, left inner fender. According to my "Haynes" wiring diagram (I know, I know..it's all I've got at the moment), there are only the plugs, the inner fender unit and the dash light. I thought that was all that made up the system.
Now, it seems, there is another relay/box under the dash,above the driver's legs, below the brake release handle.
What part, if any, does this silver metal box (relay) play in the glow system?
According to this video, it turns on the "light".
This additional "box" isn't on the wiring diagram I have. If you do a "search" for "83 240D glow plug relay", both the inner fender unit and under dash unit come up in the results.
Can't find ANY info on how they work together, if at all....

https://www.youtube.com/watch?v=LmYYASjTyzM

Although this clip pertains to a '79, I have the same silver box in my '83 240D.

If your 83 240D is indeed an 83, then it has the later parallel glow plugs with the relay mounted on the inner fender behind the driver's headlight. Please post a pic of your glow plug relay.

It's highly probable that you are mistaken with regards to the function of the silver box. What you have described sounds like the warning module. It's not a glow system component.

The silver box behind the instrument cluster glow plug relay is for the older ones that don't have the relay on the fender.

There is another silver box relay behind the instrument cluster but that is the power window relay.

When you look even in the factory service manual you need to be carful what you are reading matches your year and model because you will go to the section that is supposed to be for your year and model and will find that it has information for more then you year and model and you have to read carefully to find out if the info is what you need.

Speaking in general the Haynes, Chilton and other types of manual but there is a good portion of generic stuff they throw in, a portion of stuff that sort of skates over the issue and then they will have few sections with good info.

I just had to deal with this issue yesterday. My 92 Chevy Astro Van was not charging. When I looked in the Chilton manual it had only info on the older type Alternator I mean the type they had been using since the lat 1960's not the one for my vehicle which is different. Part of the reason is that the Manual covered to many years/models.

I bought a Bently Service manual for my Volvo 240 (they are expensive good I bought it used) because I needed information on rebuilding the differential. Only to find there is zero info for rebuilding the differential in that manual.
I was fooled because the Bently VW Rabbit manual seems to cover everything but not the Volvo Manual.

Thanks to all for your responses.... Please look at the "youtube" link I provided. In the video, he removes the "guts" from the "silver box" and actually turns on the glow plug light by manually actuating the solenoid inside. Although the poster states it's a '79, my 240D (according to the data plate) is an '83. My car also has this "silver box". I didn't think the box had anything to do with the glow plug system until I saw this video. Also, according to wiring diagram I have, the color code for glow plug lamp wire is not present on the inner fender relay (green/black on the car, black on the print). The print shows the lamp going straight to the inner fender unit, but, the wire for the lamp on the instrument cluster is not present on the inner fender unit. So, it must be spliced, or go to another connector, etc. As I mentioned, the prints shows it is not......print shows a straight, uninterrupted run.

I have the Electrical Troubleshooting Manual for the '82 diesel models. The only glow module is on the inside left fender. All functions are controlled by that module with input from the start switch.

The pre-glow system on a '79 model it quite different from an '83 version.

Glow plug system
 

Thanks, tango! That's the info I was lookin for and hoping someone could provide. Your manual, for electrical trouble shooting, is an invaluable tool for sure. I've only had the car a couple months, my first, and I definitely need to acquire some MB service documentation and manuals. All I've got, so far, is a Haynes. But even that has been helpful for a lot of info about the car. Especially the wiring diagram.
Appreciate your help!

Thanks Diesel....I have a GMC Safari and experience the same thing with the Haynes/Chilton for that vehicle. Would you be able to recommend a source for MB manuals or sections of manuals for the 240D? CDrom or downloads would be fine. I understand the "hard copy" is kinda scarce and quite pricey.

See if you can get this to work. Note that the factory service manual also has some translation issues. Sometimes the same part has different names depending on which part of the manual you are looking at.

W123 Service Manual
https://www.startekinfo.com/StarTek/outside/12265/?requestedDocId=12265

W123 manual
 

Appreciate for the link to the W123 manual. Not sure why, but I can't open the links for "Startek". Have trouble with them on my home computer (Apple) and on my Android device (phone). Don't know if it's something I'm doing or not doing, but I can't get in. Too bad, because it looks like a good site with good info. Thanks for tryin to help....

https://www.startekinfo.com/StarTek/outside/12265/program/matrix6.htm

https://www.startekinfo.com/StarTek/outside/12265/disc_2/program/matrix6.htm

The above are direct links to the W123 FSM Disc 1 and Disc2 menu pages that bypass the startup sequence ...and may(???) work with your OS.
The MBUSA hosted FSM was designed to work with the MS Internet Explorer browser and the Flash Player and doesn't always play nice other browsers.

Startek links
 

Thanks Alec. Appreciate the attempt. Neither will open on my Apple or Android. Phone says "browser not supported" and Apple says "connection is not private". Frustrating:mad:

The procedures in the link below might work to enable access to the FSM pages:

https://www.imore.com/how-view-websites-your-mac-require-internet-explorer-or-pc

Try using Firefox on your Apple. It works fine with the Startek sites or the CD manuals. They're extremely old website coding and DO require Flash. Because of the ancient coding, it doesn't work on smartphones, you have to access the site on a computer. For what it's worth, I'm typing this response on a Mac laptop and both links in this thread work for me.

Startek links
 

Thanks Alec and Diseasel...good info! I got 2 birthdays today (sister and niece) so I'll have to wait til later to give your solutions a try. Thanks for the info about the smart phones. I can just stop with that frustration:rolleyes:
I'll give Safari a shot later today. Looking forward to being able to access Startek! Thanks to all!