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My rear defogger switch hasn’t worked in years. There is no power at the orange with black stripe wire coming out of the fuse panel. I have power on both sides of the PWR ACCY Circuit breaker. I pulled the orange wire out of the fuse block and jumped it directly back to the PWR ACCY circuit breaker and the switch and defogger work as they should. How can there be power passing through the PWR ACCY circuit breaker but no power at the orange wire coming out of the fuse panel? Am I missing some jumper wire in my fuse panel?
Did you test the plug on the fuse block where the orange/black wire plugs in? I bet if you do, you will find you have no power to that plug on the fuse block. If you look right above that you see an empty slot for a 30 amp fuse. I believe that is what you are missing. The plug where your wire is plugged in is not connected to the circuit where the circuit breaker actually is, it is in the third leg of the fuse block openings. There is no way for the third leg to get power from the second leg with that fuse missing. Let us know if you have power on the fuse block where that orange/black wire goes. Then put a fuse in it if it doesn't show power and test it again.
On a different note, there does appear to be two slightly different harnesses on the 81. I have two, one I bought for parts and one that came out of my 81. They are slightly different where the defroster wire plugs in. The spare I bought looks like yours, the picture I attached is what came out of my 81. My defroster wire plugs into the port just to the bottom right on the fuse block just below the circuit breaker.
Last edited by MattoonVette; Sep 28, 2021 at 11:59 AM.
There is no power on the fuse block tab for my orange wire. The shop manual doesn't show a fuse in that location for some reason. I will definitely try a 30 amp fuse tonight.
The area where you have the red arrow in your picture is how the power gets from the powered terminal over to the tap on the fuse block where the orange/black wire plugs in. The terminal on the left side of that fuse area is the only way power gets to that tap where the orange/black plugs in. If you look at the back of the fuse block, you will see that that is an isolated connection going from the left fuse terminal down to the tap for the orange/black tap on the fuse block. Only reason I could see it is because I have the entire fuse block laying out on a table.
1981 defogger switch diagnosis
