Charley B

I notice on the '88 auto., when driving over a rough surface the headlights will simultaneously flicker to the point of actually going out for a second.

Any obvious place to start since I can't duplicate the problem in the garage?

IcemanG17

I want to say grounds....but its probably a relay dying....

On my 88 I noticed that the ABS light would occasionally come on at weird times....then after one hard stop, the relay blew and it was on all the time until I replaced it.....

Alan

Start with the easy things - loose fuses, damaged bulbs, loose bulb connectors, poor grounds (at the front to the HL looms), loose CE panel grounds (up behind).

Alan

Charley B

Thanks guys.

WallyP

Another possibility is the ignition switch - if you turn the ignition off, the headlamps go off. A momentary break in the 15 bus (ignition) might cause the flicker.

You are probably looking for something at or before the headlamp relay, as any problem after that is more likely to cause a single lamp to fail.

Bill Ball

My headlight "flicker" was a bit more dramatic - the headlights would go out for several seconds. It turned out to be the ignition switch. I suspected the large headlight combo relay was loose in it's socket, but finally I identified the switch as the issue as wiggling the key caused the lights to come back on.

Charley B

The stakes increased tonight. They went out entirely on the way home. The headlights stayed up but all lights went out including the running lights. Once I turned the switch off and the lights retracted, they would not come back up when turned on again. I jiggled all the connections I could find under a street light and circled a parking lot, hitting the rain gutters as fast as I dared, to hopefully jiggle the problem connection back to life, but to no avail.

I finally cranked the lites up by hand and used high beams and emergency flashers to get the short distance home

Since running lights are also effected, but not high beams, I assume headlight fuses and relays are not the culprit. Plus it looks like they are fused and relayed seperately.

I didn't jiggle the key, but if ignition switch, wouldn't that also affect other circuits e.g. interior lights? I did turn the ignition off and on several times.

Landseer

There are a series of contacts inside the switch. One of them drives the running lights separately from other accessories. So its plausible.

Bill Ball

The ignition switch could affect just the headlights, but I think you may need a light combo relay. The combo relay has separate high and low beam relays inside. You could pop it out, remove the cover and clean the contacts. It's an expensive relay.

Charley B

Thanks Bill, would that account for the running lights also?

WallyP

Sounds like faulty light switch or loose connection.

Check for power on Terminal 30 (medium red wire) of the light switch.

If you have power there, turn it on and check for power at the outgoing terminals.

Charley B

Is this relay 23 and 24 at bottom right of the relay panal?

I'll check the light switch next.

Charley B

The combo relay on the '82 is almost identical. There are a couple of labeling differences and two small pins on the '88 that aren't on the '82 (58 and 30B1). Would it be safe to try the '82 relay in the '88 as a test?

The '82 is PN "928 618 107 00" and the '88 is PN "928 618 107 01"

Charley B

Well I think I've narrowed it down to the combo relay. I pulled the relay, installed the '82 relay (no joy), cleaned the contacts and reinstalled the original relay. Now the headlights go up and come on but will now not retract, and still no running/tailights.

Lord knows what all I can manage to f*ck up when I mess with electrics but I guess I should pull that relay apart and clean the contacts. The 53 covers like to come off when I touch them but this thing really seems solid. Any tricks to pulling the cover off without destroying the relay?

Bill Ball

The combo relay metal cover is crimped around the base. Work the crimp back with a screwdriver or whatever. You can re-crimp it just by pushing the edge back down over the base once you clean up the insides. New, the relay is over $100. I had one go bad /non-repairable (broken contact). I bought a used one for less than 1/2 the cost of new from 928 Intl. That was 5 or 6 years ago. Still works fine.