Headlight Gremlins.

[Cobra Pilot]

I'm having headlight problems with my '81 Avanti. When the headlights are on for a short period of time, say maybe 20 minutes, they shut off along with all the dash lights. As long as I let them cool down they will come back on and then shut down again. I have done the basics and found no problems. I was wondering if the rocker switch might be the problem or the yet to be found headlight relay? Could you shed some light on where the relay is located and would this be the likely canidate for my problem? Is the relay a GM brand or made by someone else. Can you reccommend a replacement?

Thanx,

Rob

Palm Bay, Fl.

[Gunslinger]

The dash lights and headlights are on two different switches, so it doesn't seem likely that the swtiches themselves are the problem. Since they're both affected, it must be somewhere in the common wiring that's causing the problem.

Follow the wiring to see if there's a circuit breaker instead of a fuse for them. I would think the circuit breaker is bad and trips when it heats up and then works properly when it cools down. That happened to me years ago in the '63 R1 I owned with the power windows...the circuit breaker was in the engine bay and couldn't handle the heat...in fact Studebaker had issued a service bulletin to relocate such circuit breakers.

If there's no circuit breaker, look for the relay and replace it, but it sounds more like a circuit breaker.

[Ray K.]

The dash lights and headlights are on two different switches, so it doesn't seem likely that the swtiches themselves are the problem. Since they're both affected, it must be somewhere in the common wiring that's causing the problem.

Follow the wiring to see if there's a circuit breaker instead of a fuse for them. I would think the circuit breaker is bad and trips when it heats up and then works properly when it cools down. That happened to me years ago in the '63 R1 I owned with the power windows...the circuit breaker was in the engine bay and couldn't handle the heat...in fact Studebaker had issued a service bulletin to relocate such circuit breakers.

If there's no circuit breaker, look for the relay and replace it, but it sounds more like a circuit breaker.

[IndyJimW]

I'm having headlight problems with my '81 Avanti. When the headlights are on for a short period of time, say maybe 20 minutes, they shut off along with all the dash lights. As long as I let them cool down they will come back on and then shut down again. I have done the basics and found no problems. I was wondering if the rocker switch might be the problem or the yet to be found headlight relay? Could you shed some light on where the relay is located and would this be the likely canidate for my problem? Is the relay a GM brand or made by someone else. Can you reccommend a replacement?

Thanx,

Rob

Palm Bay, Fl.

Not sure what type of headlight switch you have but this was a common problem years ago with Ford switches. After years of use the plug-end to the headlight switch would start to overheat the connectors. The headlight switch had an internal breaker and would cause the lights to turn off and on. Fix was to replace headlight switch and plug-end.

Jim Wood

[Cobra Pilot]

Thanks for the leads. I rechecked all the wiring and could not find the headlight relay. Anyone have any clues where it might be hiding? I did replace the breaker and that didn't help the problem. I made a temporary jumper once the breaker tripped and the lights came on. I will try to replace the headlight rocker switch next.

Thanks again for the help,

Rob.

[Gunslinger]

The three pairs of rocker switches are all identical. Try switching the headlight pair with the blower fan pair and see if the problem goes away. If so, you know it's the switch...if not, you've eliminated it from the list of potential causes.

[MikeValent]

Rob - Bob Johnstone's website has electrical block circuit diagrams that help. I took some time and printed them all out to keep on hand. Diagram 26 shows the 1984 fuse block. My 83 fuse block is the same as the 84 and I'll bet yours is also. The headlights-park lights-tail lights and instrument lights are all on one 20 amp fuse. Someone (also from Florida, I believe) recommended replacing that with a 25 amp fuse.

A prior owner replaced that fuse in mine with a 30 amp circuit breaker. I've had only one malfunction and it behaved like yours. Headlights and instrument lights went out, then came back after a couple of minutes, then repeated. But this happened only once and it happened when one of the transmission fluid cooling hoses split right up by the radiator and was blowing fluid mist all over the engine compartment.