Horn and glove box light issue....!

[yves]

After a hard work with my heatercore refurbishment, i have reassembled all the dash devices , heater levers, clock , blower switch, glove box.....etc. first test with switching the battery ON , surprise the horns work without pushing the wheel ring ! i have disconnected the battery and check the steering wheel looking for a bad connection of the 2 wires of the ring. After that check i connected the battery and then no more horn even when i connect together the 2 wires of the steering whell ring ! and more : the glove box light doesn't light too !, the other electrical devices are OK  radio, dash lights, wipers, turn signal....
Idea?
I think about a neg issue . i have checked the N2 fuse and the continuity of the live wire at the steering circle without an issue
I am confused
I have 1.8 volt when i turn the ignition switch on between the 2 wires of the horn circle

[lpeterssen]

Dear Yves

Interesting description of events.


HORN
====


First of all, the two cables coming to the steering wheel horn switch are a GROUND FEED (brown) and a NEGATIVE RETURN signal (also a ground) the BLACK/YELLOW/ROSE cable.

The function of the horn ring is to SWITCH ON/OFF the ground that is later brought to the HORNS at each side of the radiator at the engine bay.

So as these cables coming to the horn switch are transporting a negative signal make no sense that you are reading 1.8V on them when having the multimeter on the DC voltage function.

The live (HOT) cable (POSITIVE) that feeds the horns comes directly out of the FUSE BOX and is BLACK/yellow. It comes from fuse no.2, but goes directly to the Horns, it does not pass through the STEERING WHEEL horn switch.

There is no continuity to check between fuse no.2 output and the steering wheel switch cables, since as mentioned before that is not the route that cable has.  Look carefully at the wiring diagram published on the technical section of this forum and you will realize that.


GLOVE BOX LIGHT
===========

GLove box light is a simple circuit.  On the branch that has a connector for the cigarette lighter there is a derivation first for a switch that cuts the positive feed to the glove box light fixture.  Check first that this connector is connected to the glove box door switch.

Then check if you have on any of the legs of this switch a positive 12V feed.  If you have it, next step will be to check if the light switch does its work. Check for continuity among its legs when is not depressed. (Glove box door open condition). And also check if it interrupts the circuit when fully pressed (door closed).

After the glove box switch two front connector two wires, one red/green and another brown (ground) travel to the light fixture.

My guess is that you forgot to plug the door switch connector…..

GROUND POST
=========

THere is only one ground post in the dashboard and it’s located behind the heater controls next to the ignition switch.  Accesible only if you remove the tacho and speedometer.  Those brown cables (MANY) fixed with a 10 mm nut.  It’s a good idea to disconnect it, perfectly sand and polish the surface and reinstall the ground post adding some CARBON CONDUCTIVE GREASE (not a dialectical  grease, exactly de contrary is a conductive grease) to protect this important ground post in order to have trouble free operation of all the circuits related to it.

Best regards
Eng.Leonardo Peterssen

[yves]

Thank’s Leonardo for your explanations. I’ ll check the glove box tomorrow , easy with the glove box out…
But the ground post you mentioned is more complicated. I remember that I have moved many times the ignition switch because it was not tightened and I tried to understand how it is fixed in the dash. BTW all that explain why I found on the floor a 10 mm nut  ( another thread on this forum some days ago…!) may be it was that nut which hold the ground wires you mentioned ?
So after the right side of the dash I’ll visit the left side for accès as you say to the ground wires?
Another very pleasant job….🥵
I’ll return here the progress…!🙏🏼

[yves]

Leonardo, do you know where is exactly the ground wire post you talked about?  could i have unfortunately disconnected the nut holding these ground wires when i moved the ignition switch ?

[WRe]

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

[yves]

You know what..... i am so stupid...... but now very Happy .... all is fine ! i have made an obvious mistake: i have switched the plugs between blower switch and blower motor    before attempting the left face of the dashboard ! i thought that i must have made something wrong during my precedent work and decided to check the glove box and blower  connections and BINGO , a look on the wiring diagram with the color code  was the solution.
You know what.... i'll have a nice drive on the seaside this afternoon   

[lpeterssen]

Yes that is a possibility.  The nut is very close to ignition tumbler assembly.  Let me look on my photo albums to see if I got one shot with that

[lpeterssen]

Dear Yves

As suggested by member WRe look at the section GROUND on the technical manual, there are photos of all the ground post in the car.

Also there was a previously document published on this site, made by someone in Germany who explains the instrument cluster disassembly process and there are photos that also show the grounding post near the ignition tumbler switch.

Nevertheless, here below I will post copy of those pictures for you.

https://www.sl113.org/forums/index.php?topic=27283.0

The photo from the GROUND section with a white color car is the best to show you the location of that grounding point next to ignition lock assembly, which is held by a 10 mm nut.

Best regards
L.Peterssen

[yves]

Thank's every one for your help  I'll see the ignition tumbler switch after this summer..... ! i have to drive now with the nice days coming on...
A big event for the 60 anniversary is planed around the LOIRE castles on June ....