Hi Guys and Girls, I am having an issue with the reverse lights on my 75 Mav. I replaced the bulbs and I plan on checking the fuses this weekend. Other than that, I'm stumped. The transmissions is a T5 out of a late 80s/early 90s Mustang 5.0.
The light is activated on the T5 by a switch on the left side of the transmission. You can short it at the plug to see if the lights are working, to rule out a transmission or switch issue. Question ........ did they ever work? If not, whoever put the transmission in might not have hooked that wiring up. It is easy to do.
To be honest, I'm not sure. I got the car as a project car, but I would like to drive it around this summer before I start disassembling it. I did get a second transmission with the car when I bought it. I'm hoping that its just the fuse.
Take a quick peek under the drivers side - you will see the switch on the side of the transmission - looks like this. See if it is even hooked up to anything. If not it is a pretty easy fix. Just need to hook it up. I found a switch cap with the wiring on ebay for mine.
I never saw a current rating for the T5 switch so I added a relay to mine. Don't know if it was necessary or not...
So over the weekend, I crawled under the car and discovered that the switch was unplugged. Easy fix, right? Wrong! The plug is about 1/2 inch too short. What's the best course of action. I really don't want to cut and splice, but if I have to I will.
Without being there, it is hard to picture what you have going on under there. If that is the correct plug for a T5 - someone had to have added it and I would think they would have been smart enough to get the wire length right. You can test if that plug is wired to the reverse lights by shorting the two leads (needle nose plyers in the 2 holes works nice) with the key on, and that will light up the reverse lights if that plug is connected up right. If the lights do not come on, I would trace back the wires from that plug and see where they go. Might be wiring for something else completely, like a neutral safety switch or something else.
Yeah, this car is a casserole of randomness. On top of this wiring issue, I need to chase a lose wire or ground. Every time I turn the wheel to the right, all the lights go out and the car almost shuts off. Guess that's why they call them project cars.
I feel your pain. There are few things worse than tracing down and fixing someones backyard patchwork in the wiring. But there is hope. The wiring on these cars is pretty basic and it is not very hard to pull the entire harness out and get a good look at it. With some basic skills in solder joints and shrink tubing, the bad spots can be repaired. The brain box of these old harnesses is the directional switch in the steering column. Sounds like something is getting shorted in there on those right turns.
So after getting under the car this weekend, the adapter that I thought went to the back up lights is not the correct one. the prongs on the female adapter are too close together. I looked at a wiring diagram online so I guess its a matter of wire chasing this weekend. cue the Coronas.
