LHD W.G (West Germany) wires from dimmer & dash switch to headlight relays?
07-06-2014, 05:35 PM (This post was last modified: 07-06-2014 06:34 PM by Rascal21.)
Post: #10
RE: LHD W.G (West Germany) wires from dimmer & dash switch to headlight relays?
Ok, A more detailed description:

Status earlier today:

Bosch 4-pin 30-85-86-87 relay for switch and Bosch 5-pin 30-85-86-87-87a relay for high beam/dimmer.

4-pin switch relay connection setup:
The headlight switch (Red-White wire from dash switch) is connected to 86 on (Switch wires are earthed on AE86 as you know), and 30-85 pin (linked together) gets power from battery, 87-pin has a wire that goes to the 30-pin on the 5-pin dimmer relay to power it.

5-pin high beam/dimmer relay connection setup:
Dimmer/High-beam switch (Red-Yellow wire) is spliced close to the switch to a new wire in the coupè and dragged a NEW wire through the firewall and connected to 86 on this relay, leaving the other end of the red-yellow wire that goes to instrument panel etc hanging, circumventing lots of annoying circuits that could create oscilation.
30-85 pin (linked together) gets power from the 87 wire on 4-pin relay, 87 pin is connected to low-beam headlights, and 87a pin is connected to high-beam/dimmer headlights.

Headlights White-Black wires are Grounded to chassis. (Red-Yellow not connected)

This way, I got low beam but only dimmer switch worked if i only LIGHTLY touched it.

^^This was 2 hours ago.



SO, 1 hour ago:
I traced the above problem to be located inside the dimmer/high beam column switch assembly.
It turned out that the spring loaded hard-plastic switch rod that is physically squeezed upwards to the switch by the plastic switch handle, and as a result, the hard-plastic rod had dug a crater into the plastic switch handle, this created play in the whole system and high-beam/dimmer system faulty as a result as the riveted contact leafs would not properly engage.

I solved this problem by applying some tape to the plastic switch handle where it touches the plastic switch rod, and therefore eliminating the play.

Now I had both low beam AND high beam headlights working Smile


But THEN, Status Quo.
I wanted to get the highbeam light in dash to work pending soon-to-be inspection of the car so I could get it on the road.
SO what I did was to splice the Red-Yellow wire (Which I had left cut off in order to isolate oscillation problems) and to the 86-earth wire, this for some reason created a fault in the circuit, so Low-Beam was working, but High-Beam headlights and High-Beam indicator in dash only worked when I lightly touched the dimmer..

So I removed the Red-Yellow wire from the 85-signal wire to rectify the issue, now all of a sudden I was getting oscillation, 4000rpm on gauge, ECU relay clicking and buzzing sound from the switch relay Sad


So then what I did was used the battery kill switch then removed every single connection to 12v+ EXCEPT the fused headlight relay power wire, and guess what happened?
NO changes, buzzing sound from relay, no headlights.

What in the...?

Of to buy a new 4-pin switch relay to see if that solves the issue.

New switch relay did not solve the problem either.
And when I disconnect even the bulbs, Low-Beam switch works, but High-Beam switch over only works when I lightly touch the dimmer, nothing from switch to high beam, connect brand spanking new bulbs I get buzzing and oscillation.

So I tried connecting red-white from Column Switch to red-yellow on Dash switch just like in the schematics.
Getting buzzing as soon as I turn the kill-switch..

And all this ^ with ONLY headlight relays connected to battery, everything else disconnected!
Brand new relays, brand new wires, all connections, solders, clamps, etc are fine, even brand new relay screws for gods sake Banging head


Dash switch inspected, no burnouts or anything. All solders fine.
Column switch inspected and cleaned, no burnouts or anything, All solders fine.
No burnouts anywhere, bulbs fine, new everything, everything that I know so far I`ve double checked, triple checked then kissed for good luck.

1x AE86 84` Zenki Coupè Levin 4A-GE 20v
1x AE86 83' Zenki Coupe Levin 4A-GE 16v
1x TA60 82' Sedan 2T 8V
1x TA40 78` MK1 Zenk/Pre-Facelift Wagon 4A-GE 16v
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Messages In This Thread
RE: LHD W.G (West Germany) wires from dimmer & dash switch to headlight relays? - Rascal21 - 07-06-2014 05:35 PM

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