Reverse lights

[Buffchief]

My reverse lights don't work on my 1980 fj40! Installed a new switch on the transmission and nothing. Ran a jumper to the switch and lights came on. Operated the switch and they go out. Moved up to the firewall quick disconnect and checked there and lights on and off with switch. All other gauges/lights/ heater etc... work just fine. Fuses are all good as well. Looking at the FSM , is the next powered item on same circuit the heater blower switch or ECC? Electrical stuff is my poison

 

[charliemeyer007]

Does your heater blower work? That's the same fuse. You need to look at the connectors closely. The terminals need to be clean and free of corrosion where they connect together. Also corrosion can crawl under the crimp connection ruining conductivity. Check each unit with a VOM. If the connections/fuse are good then the wire (color code LR) has broken - that's why your jumper worked.

My 72 has those glass fuses can look good but are actually bad because the wire inside broke/burnt off at the metal cap where you can't see it. Test with VOM to be sure they are good.
Disconnect the battery ground. Use a bent 30 cal bore brush to clean the fuse contact clips. Connections on the back side often get corroded or loose too.

 

[Buffchief]

Does your heater blower work? That's the same fuse. You need to look at the connectors closely. The terminals need to be clean and free of corrosion where they connect together. Also corrosion can crawl under the crimp connection ruining conductivity. Check each unit with a VOM. If the connections/fuse are good then the wire (color code LR) has broken - that's why your jumper worked.

My 72 has those glass fuses can look good but are actually bad because the wire inside broke/burnt off at the metal cap where you can't see it. Test with VOM to be sure they are good.
Disconnect the battery ground. Use a bent 30 cal bore brush to clean the fuse contact clips. Connections on the back side often get corroded or loose too.

Yes everything works but the reverse lights. I'm not sure what the last item is before the reverse switch so I'll assume a brkn wire. Was hoping for a ground after taking the rear harness out and unwrapping Will be worse behind the dash!

 

[pb4ugo]

The backup light wire going to the switch should be hot all the time when the key is on.

 

[bobm]

Bad switch

 

[Living in the Past]

Place I would start is the switch on the transmission. Wire from the front should have voltage with the switch on. If not need to move forward to find that problem. If you have power jumper the two wires and reverse lights come on you have an issue with the switch. If the lights don't work problem have issue behind the switch. Still doesn't mean the switch is working but other problems need to be fixed. If the jumper work problem is in the switch.

 

[Buffchief]

Bad switch

No second new switch. Tested wire from the front with a jumper to the switch while connected to the lights, pushed the switch and they went out. Must be somewhere behind the dash. I'm in it now.