I ran my '86 2M4 through a brushless jet carwash yesterday; as the car was being blasted under, over and from the sides with jets of water, the Service Engine indicator came on. I noticed no other symptoms on the short ride home. But this morning, when I began to set out for work before dawn, only the driver side headlight door popped up when I turned the headlights on. That was 7 1/2 hours ago and I haven't stopped cursing since. I looked over the relay connectors and fusible links but don't see anything obvious. However, it appears as though a headlight link may have burned in the past and the previous owner soldered both circuits to run through a single fusible link and wrapped it up with elec tape. The electrical connections appear sound. I'll correct that of course, but since the driver side headlight door is working properly, I don't attribute the failure of the R/H headlight door assembly to the link - but I dunno, I'm not an auto mechanic; so I turn humbly to this forum. Any thoughts, Mates?
Cheers

Welcome to the forum, I don`t think the ses light would show up because a head lamp motor assembly went out, it may have gotten into another part of your electrical system , triggering another problem, it might be an idea to run codes on your ecm and see what that turns up first, then tackle the head lamp problem, this is a tuff call , electric and all being involved . Head lamp questions are usually a buddycraigg specialty, he should be along shortly..Heres the code page below.
https://www.fiero.nl/cgi-bin/main.cgi?ECMCodes

My check engine light used to come on when in a car wash. I can't remember what the code was, but it indicated the oxygen sensor as a possibility. I replaced that, and the light no longer comes on in a car wash. As for the headlight, that's probably pure coincidence that it failed after the car wash. It was probably going to fail anyway. Swap relays, and see if the problem swaps sides. As for my car (also an 86), I upgraded to the 87+ headlight system. I'll be selling my old motors and relays (still working) on Ebay soon.

Thanks - A BuddyCraig thread cites part number 10027587 as the 86 motor relay. I find ACDelco part numbers for the Iso relay but not this one. Li'l help? I also see a prior thread that tells me the fusible link is gonna be a bugger to find.

Hello and welcome to the PFF.
With you having some imaginative wiring preformed on the car and other electrical oddities (like the check engine light coming on. I’m not really sure what to think.

But a common occurrence after driving in rain. I find the motor relay laying down on the frame and full of water.
This relay is supposed to be mounted next to the headlight.
It can take a long time for the relay to dry out if you don’t remove the outer shell.

If you discover any other clues let us know and good luck

Ah...
Yes, I had the headlight door mechanisms worked on by a shop over the summer and I did note that the R/H motor relay is not mounted, buy dangling upside down by its wiring harness next to the headlamp assembly. Now that you mention it... it clearly could have been saturated with water. I'll post again when I find out - Thanks!

quote Originally posted by SCCA FIERO:

why not!!??!?!???!???!?!!!!?!?!

Buddy was right about the actuator relay; I replaced it and headlight doors all 5X5 now. I will NEVER take my Fiero through an automatic car wash again.

I'm guessing that the sign posted above (not the carwash I went to) may be because the Fiero has such a low profile, sensors in the carwash don't trip properly...?

glad it was an easy fix.

quote Originally posted by GoKart 15022: I'm guessing that the sign posted above (not the carwash I went to) may be because the Fiero has such a low profile, sensors in the carwash don't trip properly...?

Then they should add Corvettes to that list.