Signal Lights stopped working after 5 yrs?

[Harley818]

I've been driving the car each summer for 5 yrs. Last fall the signals stopped working.
Now I am getting it on the road again and need to figure it out.
If I am reading it right, the wiring diagram for 2002 Donor below shows:
FB1-FB4 powers the LgB wire to the LH turn signal switch.
FB2 to FB5 powers the BG wire to the RH turn signal switch.

When you have ignition on, and you move the turn signal lever, it goes through the Turn signal/Hazard Module which grounds the circuit turning the light on?
I am showing no power on either wire for LgB or BG wires.
I checked fuses FB1 - FB5 and they are all OK.
Is there a relay or something powering the FB that could have failed?

Also, I checked the Hazard lights operation..... they work as they should.... flashing all 4 corners.

Stuck and wondering what it could be.......hope one of you guys can help.

Thanks.
165994

[RPGs818SNA]

That wiring diagram is really confusing, Harley, but here’s how I think it works.
Turn signal power normally comes from the ignition relay on the GW wire to the Hazard Switch.
When the Hazard Switch is OFF, GW is connected to BrR and goes to the Turn Signal & Hazard Module. That’s the blinker module.
That module applies blinking power to the BY wire which goes to the Turn Signal Switch.
The Turn Signal Switch applies blinking power to BG for left and LgB for right turns.
BG sends blinking power to Circled B to the next sheet and on to the left rear turn signal bulb. BG also connects to the fuse box FB-2 which connects to FB-5 which, on the next sheet, connects to the left front turn signal bulb. It also powers the turn indicator on the dash.
LgB works the same for the right turn signals.
If the Hazard Switch is ON, Fuse MB-6 powers the flasher module and BY powers both left and right turn signals.
So with the ignition on and hazard off, check for power on the BrR wire on the flasher module, blinking power on the BY wire, and ground on the B wire. If there’s no blinking power on BY, you may have a failed blinker module. Otherwise trace the power back through the hazard switch.
Good luck with all this. I hope it’s a quick fix.
RPG

[Alan_C]

During construction, the signal lights failed on my build. The turn signal flasher failed. Usually the flasher for the turn signals and emergency flasher are the same, try swapping them. If the turn signal flasher now works, it was the flasher.
FF supplied cheap flasher modules so I found a guaranteed for light equivalent at the Auto Parts store and replaced them both. I never had the problem occur again.

[TheHelixx]

If your Hazards work correctly then it has to be a defective turn signal switch or the broke connection from the flasher module to the turn signal switch. The hazard switch loops power back to the flasher so don’t test anything with that unplugged. I would take the bottom of the column off and verify ignition 12v at the turn signal switch. As long as the Hazards operate correctly there really is no need to look elsewhere as that verifies the rest of the loops.

[TheHelixx]

This part
166000

[Harley818]

That wiring diagram is really confusing, Harley, but here’s how I think it works.
Turn signal power normally comes from the ignition relay on the GW wire to the Hazard Switch.
When the Hazard Switch is OFF, GW is connected to BrR and goes to the Turn Signal & Hazard Module. That’s the blinker module.
That module applies blinking power to the BY wire which goes to the Turn Signal Switch.
The Turn Signal Switch applies blinking power to BG for left and LgB for right turns.
BG sends blinking power to Circled B to the next sheet and on to the left rear turn signal bulb. BG also connects to the fuse box FB-2 which connects to FB-5 which, on the next sheet, connects to the left front turn signal bulb. It also powers the turn indicator on the dash.
LgB works the same for the right turn signals.
If the Hazard Switch is ON, Fuse MB-6 powers the flasher module and BY powers both left and right turn signals.
So with the ignition on and hazard off, check for power on the BrR wire on the flasher module, blinking power on the BY wire, and ground on the B wire. If there’s no blinking power on BY, you may have a failed blinker module. Otherwise trace the power back through the hazard switch.
Good luck with all this. I hope it’s a quick fix.
RPG

Thanks RPG.
It is confusing..... I checked the power at the Hazard connection and there is power on W, but no power on GW to the Ignition relay...... I guess i need to find out where that comes from and why no power.
Thanks so far. I'll try to trace it back.

[Harley818]

If your Hazards work correctly then it has to be a defective turn signal switch or the broke connection from the flasher module to the turn signal switch. The hazard switch loops power back to the flasher so don’t test anything with that unplugged. I would take the bottom of the column off and verify ignition 12v at the turn signal switch. As long as the Hazards operate correctly there really is no need to look elsewhere as that verifies the rest of the loops.

thanks Helixx, no power coming from Ign switch so thats what I need to trace now.

[Harley818]

Found it.
traced it back to a bad fuse for the ignition.
Thought I checked them all last year, but it was one in the Main Fuse box that was hard to see......
Glad it was this easy to fix although it took a while to trace...
Thanks all.