Hey there,

Just bought an 89 Pickup and the backup lights are gone. I'm looking to replace them, but currently, the blower doesn't work normally, which is more urgent. It burns something out when the car is put in reverse and it is running.

I tested the transmission reverse switch and it's good (not shorted). The wires coming out of it have resistance, but a connection. I'm not sure if that's supposed to be the case or not. They were definitely gnarly. I actually cut them trying to clean them up and find a short, but if there's a short it somewhere else. But now I need to replace the backup switch connector since I kinda messed it up.

It seems right now the relay is dead, as I can get the blower to run when I short the large pins on the heater relay and it doesn't short anything in reverse when I have the backup switch disconnected. I did not test it with the backup switch connected.

As I mentioned, the lights are just straight up missing. I also need to figure out how to wire up a trailer, since that's also missing. There are a few cut wires at the tail, and a weird rusted out square unit that has wires going to it. Not sure what it is.

I need to take a look at all the various colors and I'm sure that will help - this is my next todo.
Hhowever the only wiring guide I've been able to find is a 1985FSM. Is that the same as the 89? Any links to an 89?

There are some weird things going on though.

Why the hell does the blower die when there's a short with the backup lights?
This seems silly...

I notice on the diagram it says the Y wire goes "to heater relay, to glow plug indicator, and to charge warning light relay'.


Why is this?

There is no "from" connection on that page, but there is a yellow wire, which seems to come form IGN fuse, which is 1-8. This diagram is labeled in a confusing way, no?



It's possible this diagram is not for my truck, or I'm confusing pages or something. I'm just trying to make sense of it.

While it may be nice ot actually get it working, I'm thinking perhaps I should just completely bypass this whole relay and just install my own relay and some new LED backup lights with all new wiring. This seems way better than trying to dig into the old ass wiring... I figure I can probably just tie into the reverse switch and it should function as intended, but without screwing the heater up.

But... what size relay?
Any other tips or ideas?
I've never done wiring along the transmission and/or exhaust, but it seems like it can get hot under there.

Thanks!

PS. The truck also has no functioning gas sensor, nor a bunch of other sensors - I think all of those oil pressure, water temp, fuel level, battery, etc. This may be what I tackle once I have heating and a backup lights




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