LHD W.G (West Germany) wires from dimmer & dash switch to headlight relays?

[Rascal21]

Hi all!

Making my usual annual nagging topic on how I can fix AE86 headlights here.
Been reading my arse off on the diagrams but I understand no more of these gibberish tell-tales today than I did 5 years ago when I got the car, but from my slightly more accumulated car mechanics knowledge at least I have pinpointed what I need to do (Make new relay setup and screw the OEM one, just leave it be).

Like title states I`m very interested in finding out which wires goes from dimmer and dashboard switch and to the headlight relays on the West German AE86`s and whether they provide ground for the relays or power as signal! Got a bunchload of relays and I`m very anxious to get the car on the road now

[The Doctor]

So, by reading through the manual...

it looks like both relays aren't powered, if you override the main relay, the lowbeam lights start working, because when the low/high beam relay isn't powered it'll give you at least low beam.


Strange..

[Bean]

I assume in five years you tested the light switch itself is fine? They are common to fail.

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[Rascal21]

Doctor, that is exactly the issue right now!

Bean Bandit, I soldered new wires into the light switch but alas no go.

I`ve completely given up on the OEM system, has to be big problems in it somewhere.

Instead I want to cut this wild goose chase and find out what the switches to relay and wire colors are and what they do (earth or power for relay signal) and fab my own system with splicing new wires as close to the switches as possible, to circumvent any troubled wires!

[Bean]

I would need to dig up the wire schematics and check, in my case the switch itself failed. Until I had a new one I temporarily fitted a toggle switch and wired that into the plug.

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[Rascal21]

Ah no, what I mean is the switch is now working, but the headlight relay is not getting power, I can hear the coupè headlight relay turn on, but the power is not getting from there and to the main headlight relay.

[Bean]

I'll see if I can find the print and make any sense out of it over the weekend.

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[Rascal21]

A friend of mine made me a schematics so I could use a simple 87-87a/87a-87b switchover relay and 30-85-86-87 relay to get the headlights working again, so that 86 pin on both relays are connected to dash switch and dimmer switch respectively, now I`m getting one of the beams working, presumably low-beam, but high beam does not work and dimmer only makes the headlights flicker..

I checked the low-high beam relay (Dimmer relay) and as it turns out, both pin 87 and 87a is giving power at the same time despite dimmer being in neutral position..

I`ve changed the dimmer/column switch assembly too and I was assured that it would work by the seller.

Thought it was oscillation so my friend had me add a diode and capacitors across the 30-85-86-87 relay pins towards earth etc, but still no go!

We are at wits end, what is it with this cars headlight system that makes things so hard for me and anyone unfortunate enough who dares help me? This issue is putting professional car electricians and experienced amateurs TO SHAME
If we had had an evil boss, most of us would have been dropped through the floor to the piranhas/sharks already!

[Bean]

do you have access to the actual diagrams? else get it here http://www.aeu86.org/technical/ae86-manuals/ the 1983 one and check page 28 and 29 (also read page 4 and 5 carefully so you understand the lingo on the other pages and where to look).

In my opinion the best way is to go methodically. Check that all fuses are fine (should be 5 in total). Also check that all light bulbs are working - both high and low beam.

If I read right in your other topic your highbeam light on dash is not working either? also be sure that the bulb is fine. If I counted right there's also 15 connectors to check for continuity and proper connection. These connectors should also help out with diagnosing the whole issue.

Am I right that you did an engine swap? did you double check that the relay board is connected properly to the rest of the system, one unlucky wire is all it takes sometimes.

Last but not least can you try and condense the current situation as factual as possible?
I.e. what happens every step of the way and how it's connected right now etc...

PS: to check if you got high or low beam just hold a piece of paper some 30cm in front of the light, you should be able to see the anti-glare pattern on low beam.

[Rascal21]

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


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


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


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.