QuestionCould the headlight switch on a 1970 Mustang Mach 1 be the cause of my automatic transmission console light not working and the backup lights not working? Do those circuits run through the headlight switch on the dashboard?
Also, Just above the radio is a button/switch labeled "sport Lamps" that doesn't seem operative. I read that in the 69-70 Mustangs this switch was made inoperative and it's function moved to the light switch on the dashboard. I have checked my replica owners manual and can't find it referenced anywhere. I guess it was just left in location to look good? It isn't wired to anything in any case.
Thanks for your help.
Greg Fisher
AnswerRotating the headlight switch does control the intensity of all the gauge lights, including the console. Since you don't mention that the gauge lights are also not working, I assume your headlight switch rheostat is working fine. The problem with your console light has to be either the bulb, the wiring to the bulb from the dash harness, or the bulb socket itself. There is no way to troubleshoot this without getting in there and inspecting the wiring and socket. While you're in there, replace the bulb with a new one even if the old one checks OK.
The backup lights depend only on the ignition being on and the shift lever being in reverse, so again, the problem is inside the console. Apparently either your backup light switch has failed or is misadjusted, or possibly, again, there is a wire disconnected. So, both of your symptoms point to the wiring in the console - it's time to take it apart for inspection. The backup lights do not have any relation with the headlight switch.
You may need the factory shop manual to assist you in getting this apart - if it isn't obvious how the covers come off.
Dick
