RAD4Runner

Correct

Unfortunately, I do not have schematic fr your model year, but I think it would be similar to 22RE's. IF you can find the components, look for these voltages with tail light switch on.



If you get 12V where they're supposed to be, trace wiring from negative side of running lights and taillights to ground. On 22RE, ground for front lights are inside right fender near fuse block, but could be different on your truck.

wyoming9

iTrader: (1)

I think your use of the word circuit while correct was wrong .

The tail light wiring is indeed in that harness!!! Has the fuse blown again did you check??

You did state the front parking lights were working now they are not.

Do like Rad says and check for system voltage

njoehow246

The fuse is good, non of the running lights wrok front or rear but the headlights work, is it possible that the combination switch coukd be bad?

RAD4Runner

Then you'll know.

njoehow246

Ok finally got all the lights workibg only thing now the brake lights dont work only when the tail lights are on any idea's? And the tail lights seem really bright like the brake lighrs are on all the time

4Crawler

iTrader: (3)

Could be a couple of things.

One is the incorrect bulb, should be a dual filament 1157 bulb (has two contacts on the bottom) and not a single filament 1156 bulb. Tail light and brake light share a dual filament bulb and the wrong bulb can cause that symptom. The brake filament is typically around 27 watts and the tail light filament about 8 watts, an 1156 bulb will typically have a single 27 watt filament. A related option could be a proper 1157 type bulb but the internal wiring has shorted together. So a tail light as bright as a brake light is a good clue that the wrong filament is being lit.

Another option is a missing ground connection. Tail light will find ground via the brake light filament and brake light via the tail light filament, but only when the opposite side is off. If you look at the bulb, you have two filaments with a common connection, that is normally tied to ground. But if you have a bad ground, you have two filaments in series and often those filaments are grounded when not energized. But if you put 12 volts on both sides of the bulb (with no ground in the center), no current flows and no light appears. Could be a bad ground wire or even a bad ground connection or contact inside the socket, for example:
- http://4crawler.com/Diesel/CheapTric...#SocketRepairs

A third option is a bad or improperly wired trailer wiring connector. Those can cause all sorts of weird symptoms like this. Easy check is to disconnect the wiring adapter (if present) and if the problem vanishes, the adapter was the likely cause.

njoehow246

Ok still having issues with the running light's front and rear checked all the grounds they are good the strange thing is they work then they dont work then they work again, also have no dash lights, and when the tail lights did work they were still bright like the brake lights were applied, I found a trailer connector and removed that crap im so frustrated with this need help, cound the combo switch cause these issues?

4Crawler

iTrader: (3)

Any aftermarket electronics like radio, CD player, gauges, etc.? If so, try disconnecting those and see if anything changes. Problem is related to most devices having a chassis ground and a lot of the Toyota lighting wiring being done with a floating ground. For example the headlights and dash lights use a switched ground connection. I ran into a similar issue after swapping out a radio/CD player in my '85. I ended up just running new/dedicated power/ground wires and then eliminated any connection top any of the dash light dimmer circuits. That solved all the problems with strange "bulbs not working at different time" problems. Trick was to note the exact combinations that caused the problem, radio on/off, headlights on/off, etc. In my case I recall it was something like if the radio and headlights were on, then the brake lights would not work, but they were fine when I checked them the next day (of course headlights and radio off) in the driveway. This was about 16 years ago, so don't recall the exact details.

njoehow246

Ok thanks, but this is also an 85 it has no radio right now all aftermarket accessories have been removed so should I just run a new ground wire? Its just so strange how only the running/tail lights dont work and then work at random times

4Crawler

iTrader: (3)

The power and ground I ran was to the radio. Since you have none, that probably would not apply. You might try running a temporary ground wire to the back or front and see if that changes anything.

Basic idea is to troubleshoot and locate the root cause of the problem, basically divide and conquer. For example, assuming your battery/alternator are putting out 12 volts and the light bulbs are good, then you know the problem lies some place in between the two. So find some place in between the two end points and either find a way to test that when the problem appears or else find a way to bypass the wiring between the battery and there and see if anything changes. If that finds or fixes the problem, the cause exists in the half of the circuit you bypassed. If it does not help, it is in the other half of the circuit. Repeat until you find the place where the problem is. And with issues like that, you can't just look at a ground or power connection and say it is OK. Best to pull it apart, clean and check the wiring; wire could be broken inside the insulation, ground point could be corroded under the terminal, etc.

njoehow246

Ok check this out today I was working on the running light issue and I found out this really weird issue with the headlight switch on, when I step on the brakes the dash lights running lights and brakes lights come on when I take my foot off the brakes the tail lights and dash lighs go off when the headlight switch is off only the brake lights work?

4Crawler

iTrader: (3)

Still sounds like a bad ground, bulb, or short between some of the wiring. Sounds like your brake and/or head lights are supplying power to those other light circuits.

One thing to try is remove most of the light bulbs, say leave in just one brake or running light bulb at a time. Then test and see if anything changes. For example, one front running light bulb and nothing in back and if if the brakes still affect the running lights.

Then if removing bulbs changes things, another test is to check voltages at the various bulb socket pins with and without the headlight switch on and brakes applied and not. See if you can find any differences in voltage at all the socket contacts, including the ground (side) connection for each socket. Then start adding a bulb at a time and see when you notice changes in readings. Based on those readings, go to the FSM wiring diagram and see how those readings relate to the way the wiring is supposed to be hooked up.

njoehow246

Ok awesome ill try that tomorrow and post what I find thanks so much for your help