Have an FMX trans in my 70 Mach1. Backup lights don't work on the car. On my other 70 it has a C4 and was able to replaceneutral safety switch to get working. Not as fmiliar with FMX - any tips on chasing problem down. thanks

 

Me either but backup light switch??? Ya i know basic, but thats all I can think of.

 

There's a fuse you can check, else locate the BU light switch (probably on the trans) Locate and jumper around it to see if the lites come on.

 

Out of the firewall, near the master cylinder, there is a plug with four wires in the connector. Two wires are for your backup lights and two are for the neutral safety switch. I do not have my wiring diagram with me, but a color code diagram will help you locate them. You can jumper that backup light wires to manual check the lights. If they come on, it is probably a switch issue. The switch should be mounted on the tranny and makes contact when the linkage hits it while in reverse. I could tell you exactly on a toploader where to look, but I suggest you trace the wires from the firewall to find the switch.

 

Thanks I'll try jumping wires and see what happens. thanks

 

check your bulbs, the PO of my car put a 1 prong-er in it when its supposed to be 2 and it worked, but eventually melted the plastic and eventually fudged it up and now I need a new one.

 

Was the bulbs. Ended up switchng out the sockets with receptacle thatI can now run 1156 bulbs in -$10 and now I have backup lights - woo hoo!!

 

wait you can switch out the sockets? do tell I could maybe fix my light then without having to buy one. What do you do?

 

Generic socket, silicone sealer, it ain't pretty from the back but it will work til you feel like do'in it right!