OK, here's a good one to figure out...

Just installed a new 12 circuit, universal Painless harness in my 67 F-100. Everything works except for the Right Rear turn signal. The emergency flashers work just fine and all four corners blink. The left front and left rear turn signals works fine. Even the right front turn signal blinks. Only the right rear turn signal does not work. By-the-way there is a brand new turn signal switch installed and all grounds seems to be fine.

Help if you can. I have been tracing wires with a meter and test light all day and cannot figure this one out.

Thanks

 

That's wierd. This thread showed up twice. How do I delete one?

 

Does one the turn signal blink with the brakes applied? I am assuming your using a 2 bulb tail light and not a three bulb harness. The brake lights and turn signals run off the same filament. Isolate the bulb as working properly, but I think the problem is in the switch.

 

This is the intergrated turn/brake light where the stop light has two filaments in the same bulb. I have determined that the bulb does work properly as it does blink with the emergency flasher.

I was leaning towards a bad swich aslo, but its brand new.

 

Does the right rear brake light work?

 

Yes, the right rear brake light does work. It works with the lights on or off and it also works with the emergency flashers blinking. As far as I can tell the brake lights and everything else is working properly. Only the RR turn signal does not blink, even though it blinks when the emergency flashers are on.

It's very strange.

 

Have you tried appling 12v to right side wiring at the switch? What does the front do? Will the RF flash on turn signal? I still think you have a bum or mis wired switch, feeding ground to that side.

 

That's the strange part. The Right Front does blink. Only that Right Rear doesn't blink. It is very frustrating. I think I have worn my test light out!!!

 

Have you ever had a wiring problem make you want to sell your truck? I have spent another day trying to chase down this problem and am now more frustrated. I might need to lay off of it for a few days and come back with a fresh mind.

One quick question. On the 67 truck the rear tail, rear turn and rear brake lights are all integrated into the same bulb. What is supposed to happen to the blinking when the brake pedal is pressed? Does the blinking stop and the brake light shine or is the blinking continue?

Highly frustrated.

 

I does sound like the switch, or maybe a wiring problem at the turnsignal switch.

There are 3 sections to the switch. There is one section dedicated to the front turns. So that is the explanation to why they work.

One other section is for the hazards. It's totally seperate with it's own flasher.

The other section is for the rear. The rear lights have two jobs on one filament in the bulb; brake and turn.

There are two inputs to the rear part switch that we are concerned about. The turn flasher and the voltage from the brake switch. When the switch is in the center position, the voltage from the brake switch is connected to both rear lights. When the switch is moved to one side or the other, the brake switch voltage is still connected to one side, but the voltage from the brake switch is disconnected from the other side and the turnsignal flasher is connected instead. The same thing happens when the switch is moved in the other directionm but it swaps sides.

So if the brake light is working on the right, that tells me the bulb, and the wiring to the rear is ok, and the switch is not applying the flasher signal to the circuit properly when the switch is moved in that direction.

 

Thanks Franklin2,

I think I know what I did. The switch is most likely fine. I do not think I fully understood how the mechanics of the turn signal switch worked until your post. My brake wire may be wired to the wrong point. I'll do some more checking in the morning.

Is there a detailed schematic of the internals of the turn signal switch anywhere? I need to make sure I am certain how the turn signal switch works as far as where the voltage goes when it is in each position, with and without the brakes applied.

Thanks again.

 

Here's a diagram that is a good representation of the circuit. You may have to study it for awhile, it's a little bit involved.

http://www.autozone.com/images/cds/g...3d801775b3.gif

 

OK, I think I'll give up!! I think I have tried everything. It may be a bad Harness from Painless?? I will give Painless a call to see if their Tech Support can lend a hand. I have tried two different turn switches, tried it with and without the Emergency flasher switch hooked up, tried various ways of wiring it. It seems to get more difficult as I go. The Brake switch seems to be functioning properly.

I'm at a loss!

 

Talked to Painless and they seem to think it could be a faulty hazard switch. I'll bypass the hazard flasher and see what I get. Hopefully, luck will be on my side.

 

I do not think bypassing the hazard flasher is going to do anything. The hazard flasher feeds the switch. But the hazard button is part of the switch, or you have the type where the hazard switch is a seperate switch.

Do you have a voltmeter and does it have an ohms scale or maybe you have a digital with a continuity buzzer? If you do, set the meter up to rx1 or continuity so the beeper beeps when you touch the meter leads together, and or the meter needle or readout goes to zero when the leads are touched together.

After you get the meter going, put the turnsignal switch in the center position. Put one lead of the meter on the wire coming out of the switch that goes to the brake switch. Put the other meter lead on one of the rear brake/turn wires. The meter should read zero or beep. Put the meter lead on the other rear brake turn, and the meter should read zero or beep. With the switch in the center position, both rear bulb wires should be connected to the brake switch wire through the switch.

If you move the switch to the left or the right, and do the above test again, you should have continuity on one of the rear wires, but not the other. When you move the switch in the other direction, continuity should be lost on the one rear wire, but be gained on the other.

The next test is where the problem is. Take the one meter lead off the wire going to the brake switch, and move it to the wire on the switch that goes to the turnsignal flasher.

Do the test again with the one meter lead on the turn flasher wire and the other meter lead on one of the rear wires. You should find with the switch in the center position, you do not have continuity on either rear wire. When you move the switch to the left, you should have continuity between the left rear wire and the turn flasher wire through the switch. When you move the lever to the right, you should have continuity between the turnsignal flasher wire and the right rear wire.