Lost all dash lights and park/tail lights

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Mr.gristle
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My tercel:: 1986 SR5 4WD no mods yet just getting ahead of potential problems with a ton of preventative maintenance

Lost all dash lights and park/tail lights

Post by Mr.gristle »

I was replacing my speedometer cable yesterday and while the cluster was out I accidentally touched the left-most harness plug with my ring and heard a tiny electrical pop. After reassembling the dash I noticed I had no illumination in the cluster or HVAC but had all the exterior lights still. Earlier I was going to drive to the store and realized I now have no park or tail lamps. New fuses blow the second you hit the light switch. Did that short I caused ruin the light switch stalk? I removed the cluster again and the ground on the harness side I touched shows continuity to the body but cannot get power to the (4th) pin which looks to be the supply wire for the lights? Any suggestions, I'm lost, currently
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dlb
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My tercel:: '87 sr5, '83 dlx parts car
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Re: Lost all dash lights and park/tail lights

Post by dlb »

If fuses are blowing as soon as you turn the running lights on, something must still be grounding out on that circuit. That seems odd though since all you did was replace the speedo cable -- could any of the screws fastening the cluster have penetrated the wires? I don't know what else could be causing the fuse to keep blowing. Did you do anything else in there while you were doing the speedo cable job?
Mr.gristle
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Posts: 12
Joined: Fri Sep 16, 2022 10:48 pm
My tercel:: 1986 SR5 4WD no mods yet just getting ahead of potential problems with a ton of preventative maintenance

Re: Lost all dash lights and park/tail lights

Post by Mr.gristle »

The only thing I'm aware of was the small pop I heard when my ring contacted the harness. I dug back into it a few hours ago and see no obvious damage to wire insulation. Pulled the plastic from the column and everything there LOOKS fine. I think a specific wire has arced and defaulted to a ground. The wire that should provide 12V when the lights switch on is now showing continuity to ground, unless I've misread my diagram.
Mr.gristle
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Posts: 12
Joined: Fri Sep 16, 2022 10:48 pm
My tercel:: 1986 SR5 4WD no mods yet just getting ahead of potential problems with a ton of preventative maintenance

Re: Lost all dash lights and park/tail lights

Post by Mr.gristle »

This issue was fixed long ago but totally forgot to post the solution. To save myself further frustration I purchased a full wiring diagram booklet from Ebay. The ground in that lighting circuit starts at the switch, goes out to every light, back to the instrument panel, out to the HVAC controls, and then to the radio before ending at the rheostat/dash light dimmer. The radio had never produced sound but it had always turned on and illuminated. I unplugged the harness from the radio and, voila...lights. something inside the radio had shorted out. I used this as an excuse to finally install a used CD player and modern speakers
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dlb
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My tercel:: '87 sr5, '83 dlx parts car
Location: bc, canada

Re: Lost all dash lights and park/tail lights

Post by dlb »

Wow, that's amazing you tracked the problem down to the radio, of all things. Good for you, and thanks for sharing. You never know when info like this might come in handy for someone else one day.
Mr.gristle
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Posts: 12
Joined: Fri Sep 16, 2022 10:48 pm
My tercel:: 1986 SR5 4WD no mods yet just getting ahead of potential problems with a ton of preventative maintenance

Re: Lost all dash lights and park/tail lights

Post by Mr.gristle »

Yes that vintage Toyota wiring diagram covers absolutely every system in great detail with 5 panel pull~out pages for easy comprehension and only cost 9 bucks from Atlantic city pickers on EBAY. Maybe one of the best purchases I've ever made. The same day it arrived the problem was dealt with
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NWMO
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Re: Lost all dash lights and park/tail lights

Post by NWMO »

Great job!
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