Greetings,

I am new to Third Gen so bear with me. I have the classic headlight motor problem many of you seem to have. My specifics are:

Driver Side Lamp - Will go up but not down
Passenger Side Lamp - Will not go up or down. No motor noise when engaged, no motor run-on.

Both light illuminate.

I have not started trouble shooting yet but have the schematic. My understanding of the 86 config is that there is:

1 - Isolation Relay connected to each headlight actuator relay
2 - Headlight Motor Actuator relays (One connected to each motor)
3 - Fusible Links B C and D

In researching potential replacement parts it looks like the most sought after part is the isolation Relay, GM Part # 10022620, which is no longer available from GM, However, the part does cross-references to Napa Part AR 6433. This part is on perpetual back-order. After exhausting several other sources, such as classicindustries.com, it does not appear that this relay is readily available. It has 6 relays terminals built into it making it unique and basically I cannot find it anywhere. Anyone have any suggestions? Fortunately I potentially need only 1.

As for the Headlight Motor Actuator Relay, GM Part # 10031018, which cross-references to Napa Part # AR 690 under multiple applications such as "Fog Lamp" relay, "Headlight Actuator" relay, "Headlight Motor" relay. This relay, unlike the "Isolation" relay, has only 2 relay terminals which is why it probably cross populates in use to other components. The Napa parts cost is only $ 20.19 and is abundant supply so this does not concern me. It is also available as a GM OER part from dealerships for $ 45.92 retail or $ 28.24 from newgmparts.com.

Now for the questions:

1. Given my symptoms, where should I start and what progressions should I use in order to debug the problem. Start with the isolation relay if I can locate a new one? Swap out the actuator relays and see if the passenger side behaves like the drivers side? By a new actuator relay?, Check fusible links?, etc.
2. Where exactly is the Isolation relay. Is it easily visible with the hood open. There is a similar looking relay right next to the Window Washer fluid reservoir but the wiring harness seems to lead directly to the headlight bulb not the headlight motor. Do I need to look down by the radiator or perhaps from under the car from ground up? I took a picture of the one I can easily see (See Attached). There is one just like it on the passenger side. But is is my understanding that there is only one that controls both headlight motors and it is located on the drivers side. Please help me ID it.
3. Any way to test the motors independent from the switch inside the car like jumping the to a car battery? Obviously I do not want to take the motors out if they are not bad.
4. Would I be correct in assuming the headlight motor is good if it goes up but not down?

Any advice anyone has would be greatly appreciated.

Thanks,

Ed
eca1987

 

Another part number you might try for the isolation relay is 10038949. It is located on rad support firewall, engine side. It is behind the right (passenger) side headlight. The headlight relays 10031018 are easy to get. There is one for each side. Try swapping these and see if your headlight problems are consistent...may be able to eliminate the motor relays out of your problems.

 

Bringing back an old thread. I am curious about that Napa Ar6433 isolation relay. They show it as available when I looked online. It does not show a cross reference to a GM part number though. It is also not listed as an isolation relay, and they look exactly like the headlamp motor actuator relays so it is hard to tell if it is the right one. How did you cross reference that part number to the original GM part number? I would like to pick one up for an extra if it is still available.

 

Where are those fuseable links located I have 86 t/a neither heads witll come up or down with the switch all the relays are clicking and if you start to move the manual motors down with the headlights up they shoot down once you pass a certain point. Sorry for high jacking this post.

 

If they're the links I think you're looking for, they should be near the master cylinder. Though I'm not sure about color by year, I think they're red with a white stripe. You'll know it if they're blown. One look'll tell ya.