laskt9

1987 pickup. when I have the lights on my right tail light is lit up by my left is not (could be a dead bulb haven't checked)

the cluster lights come on and the right turn signal arrow will glow dimly.

when I press the brakes the turn signal arrow will light up as if the turn signal is on solid. also the right tail light will go out and the right turn signal comes on solid

also when I turn the turn signal on sometimes it flashes normal sometimes not.

I imagine it is a ground issue but I'm not sure where they ground at

slow-mo

I'd recommend an immediate exorcism.







Other than that, you'll need to get the wiring diagram for your year to start tracing down the wires in those faulty circuits. It will also show you were the ground points are as well.

laskt9

I was planning on getting it from work today but was too busy with other cars. just seeing if anyone else has had this issue.

scope103

Yes, most likely a ground condition. Start by taking the taillights apart and just looking; they are in a corrosive environment and can have obvious faults. Next, of course, you will be using a multimeter.

https://www.yotatech.com/forums/f116...lights-261959/

INFINITY

ground gremlin

slow-mo

You may have a bad instrument cluster that's causing the issue.

You'll have to give it some time for others to chime in.

The best thing to do is to get the Toyota wiring diagram to be able to diagnose stuff like this.

snap-on

you have a trailer hitch with trailer wiring hookup?

toyota uses seperate turn signals and brake lights so you have to get a converter to run both together for the trailer.

bad converter or connections at it. Check grounds like others have said.

laskt9

I've heard of the trailer wiring issue. ill bring home my dmm and check the wires tomorrow. its cold out and I have a couple other Toyotas I can drive so its not a high priority to fix

laskt9

still cold out so haven't looked too hard but apparently the person who had it before me wired lights up under the truck into the harness under the bed. I'm betting that's part of the problem. also will need to cut and weld part of the frame as it is rusty

XtraSlow_XtraCab

x2 with Snap-Ons suggestion but it sounds like you're on a good track with the rinky-dink wiring underneath.

laskt9

removed the wiring. no change. the bulb sockets in the tail light are very corroded. anyone have a fsm for an 87 still have no luck finding a good wiring diagram. need to know where the ground is

scope103

I can't tell you "where" the ground is on your truck, but you've only got so many possibilities. Start by putting a meter on each wire going to the socket, and have someone work the lights/brakes/turn signals.

MOST likely you have an open ground; the ground wire to the socket is not connecting through to the bulb. When you press on the brake the brake light has no ground return, so it returns through the other filament (the turn signal) and you get your problem.

wyoming9

iTrader: (1)

:jessica: the problem i would bet is right in your tail light sockets .

The tail lights and turn signal ground in the sockets in the mid or late eighties trucks they change when I am not sure. to separate ground wire for each socket .

Clean your sockets Or replace the complete light assembly

If you didn`t know the White wire black stripe is your ground wire there are a few ground points for the turn signals and tail lights.

tail light right fender.

turn signals right and left rear side panels left kick panel right fender

look for the white/black stripe wires screwed into the sheet metal :jessica:

YotaWoRx

Ditto. Clean the sockets and replace all the bulbs in the tail lights.

laskt9

jumped ground to black white wires coming out of sockets and it works as it should. will spend tomorrow following wire up the truck looking for where it goes to the frame I guess

Pat8942

Why not just clip the wire coming from the socket and put a ring terminal on it and ground it in a convenient location, a ground is a ground, why bother tracing a wire if you don't have to.

stock87

Check the tail bulb too to see if one of the filaments has drooped onto the other. I've seen systems back feed to the dash lights if that happens.

Green 88

I just fixed this on my '88 a couple weeks ago. It's a bad ground at the tail kight housings themselves. It could be a poor connection at one of the rivets that hold the wire to the socket, or corrosion inside the socket itself, or (least likely) a broken wire inside the harness. The reason it backfeeds through the blinker is because the tail light housing is metal and it is mounted to the body with plastic snap in nuts so it goes to the only ground it can find (through the blinker bulb fillimint).
On my truck the rivets had poor connections on the one of the tail lights. I cleaned up the rivets and outside of the socket with a bench mounted wire wheel and soldered it with a little butane Blazer torch and electrical solder with flux in it. The other tail light had severely corroded sockets. A tiny wire brush on a Dremmel cleaned it up and dielectric grease sealed it up (hopefully).

scope103

Just be careful with this. On my '94, the bed is electrically insulated (by the shock mounts) from the battery ground. So connecting a ring terminal to the nearest piece of sheet metal won't work for me. I had to "steal" a ground from a known-good ground wire to the rear light assembly.