Relays? Again?

[lpeterssen]

Dear Viard

I have an idea of the functionality of that third screwed terminals relay (5 terminals).

Of course as your harness is old and time erases everything, your color description of each cable is not accurate.

This is what you indicated, and here after what I think it should be:

Terminal 85 (control pin) = Brown (ground all the time). Correct
Terminal 86 (control pin) =  Yellow / grey.  NO suggestion on this
Terminal 30/51 (feed) =. White/violet.  NO, it should be WHITE / YELLOW, and is the Headlight feed wire
Terminal 87 (output position 1) = Yellow (correct). This is the LOW BEAM output for headlights
Terminal 87a (output position 2) = White (correct). This is the HIGH BEAM output for headlights

So my opinion after thinking the issue some time, is that this is a kind of two position output relay for the headlights or something related to them.

Normally the HIGH BEAM/LOW BEAM headlight switching is made by the muli-function steering wheel switch assembly on W113.  On W111 that is done via a foot operated switch if your car is prior to 1967.

It may be the case that you have an originally installed accessory that uses the headlight signal for some purpose.

The first thing to do to confirm my hypothesis, will be to check if cable attached to terminal 30 is hot when you turn on the headlights via the main light switch at the dashboard.

Then if that is true go forward to look what is not connected near headlights at front of the car.

Remember that on a standard W113, each headlight is fed through the main fuse box on circuits 9/10 and 11/12.

Best regards
Eng. Leonardo Peterssen
Www.wiredoktor.com
Visit my website

Dear friends / Viard

Illumination came to my mind, i know now what that strange relay should be doing….

Let’ s start from the beginning as any Sherlock Holmes investigation….

1. It is a 5 Prong relay.
==============

So its intended purpose is to select between two posible answers.  One answer will go through port 87, and the other for port 87A

2. It is a permute relay
===============

Which means that at each terminal 86 activation it will switch and stay in that position either 87 or 87A

3. It has screwed in terminals , not plug in as regular Mercedes relays used on W113
=====================================================
So this is an aftermarket addition

4. Cable colors
==========

Viard said that terminal 30 (input side of the relay for the switching load) was WHITE/VIOLET, and I thought it was incorrect and should be WHITE/YELLOW.  Definitely Viard was RIGHT.

WHITE/VIOLET is the color that normally Mercedes uses for the HIGH BEAM HORN, which was forbidden on US sold cars, but was of common use on European cars.  This LIGHT HORN was activated by pulling the steering multiswitch toward the driver, with the car running or at IGNITION OFF position.

So, VIARD said that port 86 (trigger positive signal) was fed with a gray/yellow wire. And that port 85 was connected to a BROWN wire which means constant ground.

And output wires 87 to YELLOW which is the colour used for LOW BEAM, AND FINALLY WHITE to 87A which is the colour used for HIGH BEAM.

THE CONCLUSION is that this strange relay what does is to switch the LIGHT HORN (white/violet) toward the LOW BEAM circuit (YELLOW) or the HIGH BEAM circuit, every time the GRAY/YELLOW (86) Wire is triggered.

So confirm that this is so by looking at the route that have the WHITE and YELLOW cables.  They should go to the MAIN FUSE BOX input side on port 9 and 11.


Have all a nice day.

Happy to have solved this mystery.

Best regards
Eng. Leonardo Peterssen
www.wiredoktor.com
Visit my site

[Philippe VIARD]

thank you all for your ideas and suggestions

[Philippe VIARD]

Attn: Ipetersen,
I checked the different terminals of my relay with a sample lamp .
I confirm that the thread of the terminal 30/51 is white/purple and not white/yellow.
Terminal 30/51 receives current only in headlight .
when the switch is in the headlight position
Terminals 85/86 are supplied in the pilot position or when the fog lamps are switched on
Terminal 87 is supplied with low beam only (neither pilot, headlight nor fog lamps)
Terminal 87a is powered by headlight only (neither pilot nor dipped light nor by fog lamps)
thank you for your help because this relay does not appear on the electrical schema.
This Bosch 0332 200 009 relay must be in the vehicle’s first aid kit!
cordially

[Philippe VIARD]

Bravo to Ipeterssen,
I found old information, which can be used for the realization of electric beams, about this relay for French cars in relation to the legislation of the time.
Fog lamps can only work with night lights.
To comply with the law, the W113 sold in France received an assembly in post equipment (the famous relay) either on leaving the factory or by the importer. This explains that the assembly, apart from the connections, is identical to the original color assembly of the insulators of the electric wires.
Another aspect of French legislation in the city at night the cars were running on a night light. Headlight calls were prohibited but not low beam call! which is why the blue indicator light on the dashboard does not light up.
cordially

[lpeterssen]

Dear Philippe

Thanks for your comments. I am very happy to have solved the puzzle just by deduction.

If you ever need my wiring harnesses rebuilt service I will be more than happy to work on it to bring your car back to how it came out of the assembly line.

Any retrofit is possible.

Best regards
L.Peterssen
Www.wiredoktor.com

[clunker]

With respect, I am a bit concerned that the image we have on the Technical Manual (https://www.sl113.org/wiki/Electrical/EmissionControlSystem) relating to this 4th relay is mislabeled, with the FIP and CSV switched. (I understand it is possible they may be in a different sequence on some vehicles if they inadvertently switched). I propose to part update this with the following diagram (attached) based upon that image, together with the information garnered from this and other threads on the background to this relay. If more knowledgeable persons could confirm this is correct or what needs editing, then I could make the update. Thanks.

[Leester]

With respect to the ballast resistor, I have seen some comments that it it redundant and others that even with the 123 ignition, the ballast resistor affords protection to the coil. I have no expertise as to this matter and therefore have no opinion. Really just posing it as a question. Appreciate your efforts to contribute to the technical manual.  Lee

[clunker]

Thanks. I believe 123ignition is very explicit that the ballast resistor should be bypassed - I understand its purpose it to protect the mechanical points (which are now electronic), not the coil. With it bypassed it is no longer part of the circuit, nor is the 4th relay output.

[BobH]

With respect, I am a bit concerned that the image we have on the Technical Manual (https://www.sl113.org/wiki/Electrical/EmissionControlSystem) relating to this 4th relay is mislabeled, with the FIP and CSV switched. (I understand it is possible they may be in a different sequence on some vehicles if they inadvertently switched). I propose to part update this with the following diagram (attached) based upon that image, together with the information garnered from this and other threads on the background to this relay. If more knowledgeable persons could confirm this is correct or what needs editing, then I could make the update. Thanks.

Hello, the purpose of the 4th relay seems to have caused confusion over the years, probably because it seems to have a different purpose depending on the year of the car

In my opinion, i don't think any changes to JA's description in the emission control section should be changed, or even added to, as the 4th relay description in there is specific to an emission control car, and it may be confusing

As the relay was used in cars before emission control, then perhaps add the description and picture in the ignition/coil section,

https://www.sl113.org/wiki/Electrical/IgnitionCoil

where there is already a schematic of the relay used to short out the ballast, as well as another schematic showing the later solution with the wire direct from the starter.  It might be helpful to show where this shorting relay is actually located and may help to solve some of the confusion

Just my opinion, from someone who is easily confused!

[clunker]

Bob, I think you make a very fair point.

My concern is that the picture which is at the head of this thread has been included in the technical manual under the emissions section and refers to the 4th relay in the context of this production interval in 1968–1969, which is not part of the emission system but effectively a starting aid. Putting this specific use case for the 4th relay in the ignition section as you propose seems to make sense, suitably cross referenced.

Of course JA’s notes on its use in emissions control in later vehicles should remain unchanged in that correct emissions control section.

[BobH]

Hello Charles, agreed, it can't hurt to put a note in the emission section, stating the different use of the 4th relay in the earlier cars, with a cross reference to the ignition/coil page, it will help to make it clearer

Thanks

Bob