Another Lighting Issue Q & Dash Plug Identify :)

[Sitdown]

Hey All -- Been bringing back to life an '86 SVO that sat for well over a decade...


Lighting Issues - Upon getting the car it had many inoperable electrical items, but resolved most going through the panel and replacing fuses/checking connections. Been lurking all older related posts/solutions here on topic, but still a issues, any further guidance/options are much appreciated!

Not functioning:
Taillights
Parking lights
Dash Gauges Illumination
License Plate Light
Fogs (may be a separate issue though)

Working:
Headlights
High Beams
Turn signals (Inner, Outer, & Rear)
Brake lights (Rear & 3rd)
Gauges
Warning Lights
Horn
Chime Buzzers (Both)
Clock
Fuel Door
Wipers
Windows
Locks
Dome light (finnicky, but believe that’s connection related at the fixture itself)

*Fuses: Both 4 & 8 were blown & replaced (Though I believe headlights worked still w/ blown #4?)
*I did swap in a new headlamp switch (Prem one)… sadly same result
*Other Solutions on brain:
- I recently ordered a new headlight switch repair plug (fog too) to try…
- think a Multifuction Switch may be a factor? (blinkers/Hazards do work though, slight delay on them maybe)
- Pull down fuse panel to check all back connections...
- Brown wire from HL switch looks to be primary feed for parking/lic plate lights...

Any other ideas? Possibly related, another item below…




Can anyone identify this plugs source? Figured before I go too crazy tracing things down (several hours engulfed in 86 wiring diagrams lately), figured i'd check for an easy answer here Can anyone identify this grey plug under the dash? Radio or fog light related?

Grey Plug
Orange w/ Light Blue
Yellow w/ Brown or Black - Another Yellow w/ brown wire is looped & cut to other end of plug
Light Blue w/ Purple – looped
Light Green w/ Yellow – looped & cut

The OE radio was uninstalled in the car, so may be related here (aftermarket radio equip?) and/or issues above…


Images of plug:
http://drive.google.com/uc?export=vi...Yvi23wwoHDRAy5

http://drive.google.com/uc?export=vi...UQiOqmaugiPYXs

http://drive.google.com/uc?export=vi...Yvi23wwoHDRAy5


Shared Tmoss diagram for reference

[droopie85gt]

Your best bet is to download the wiring diagrams that are stickied at the top of this forum and look on EBAY for an 86 EVTM. I know the foglights have their own (at least on my 85) fusible link and the switch under the dash actuates a relay (which I think is next to the switch). On mine, I have to rock the switch back and forth to get them to come on. It's sitting right now, so I am not worried about it, but I will need to figure out if the switch or relay is worn out.

I think the wiring on the 86 may be similar, but if I remember, the battery is moved to the driver's side like all the Aero cars, so I bet there's a lot different between 85 and 86. I can try to help out, because I have completely removed all the fusible links and put in a fuse/relay box underhood and have the diagrams and EVTM for 85.

A decent digital volt meter and test light will help trace problems. If you have the budget one of those more expensive test rigs that can power circuits would be a big help also.

[Sitdown]

Thanks, Yes have DL'd a the library of great data provided here, just hoped to narrow down potential targets

I did overlook that my fuse #4 had blown again since replacing... Based on the Fuse diagrams, wouldn't I expect my headlights to go as well with this fuse gone? As noted above, my headlights still function despite this fuse blown. I did toss in another fuse, 20a (didnt have another 15a at time) which did not blow but issue remained as before.

Given what i'm seeing, guessing I just need to break out a meter go through it all now