Ok, so I have a mess of wiring to fix (tackling all the I have been doing on my DD, with only weekends to tear apart, mod and reassemble before monday was a bad idea, LOL, I'm gonna get a different DD)... But my immediate problem is my brake lights. My high mount stop lamp works fine when I apply the brakes but my actual brake lights do not! I would have never imagined they would be on separate circuits but apparently they are.
So, long story short, I just moved and all my diagrams are packed up (I know, convenient).. anyone know off hand where the brake light signal splits or just where to look to find the cause?
Turn signal switch (aka multifunction).
oh god... LOL do you have any idea what you're saying to me?!? :beatyoass: jk, it's ok. oh man, this could be rough!
Could you explain real quick how the signal gets from the pedal, to the multi func sw and how it is split? The reason I ask is because I have to then translate it into the thunderbird meets 2002 mustang multi func sw and wiring... I think I'm going to need to dig up my diagrams and rebuttstuffyze every connection I made :punchballs:
It really makes me wonder how long they've been out... but i was tailed by a cop all the way down the hill and over 5-6 speed bumps a week ago. He didn't pul me over. must be a new issue!
The T-Bird and Mustang tail light wiring is similar. Power goes from the brake switch to the multifunction switch, where it then goes to the tail lights IF no signal lights are turned on.
If you turn on a signal light, the multifunction switch breaks the circuit to that side and reroutes it through the turn signal flasher, which gives you brake lights on one side and flashing turn signals on the other.
ok, then I think it's related to the auto lamp problems I've been having (AL turns on headlights always, never markers/tails and I have to manually pull the switch out to get headlights AND markers/tails). Thanks... i think my next step will be to temporarily bypass the AL system.
The autolamp feature is not involved with the brake lights. Rear running lights yes but not the brake lights.
See pages 94 and 95 in jcassity's 1987 EVTM sticky.
I know, I guess it was unrelated to everyone here, but in my mind it is related because of some other issues with the entire lighting system and bypassing it will eliminate some extra variables... Just ignore that last comment, it was me thinking out loud! LOL
Ok, so forget all that... I checked out my autolamp/py alarm issues, no go.
So I resorted to the EVTM (Thanks Scott, my disc is packed up after moving so I used your photobucket evtm!) and I did see where the high mount stop lamp runs straight off the pedal switch. I also saw where the turn/stop lamps are wired to the multi func sw. So, my initial thought is that, if the brake lights don't function, the turn/hazards shouldn't either. But they do... Ok, bulbs are good, pedal switch is good, multi func sw seems like it should be ok. Any thoughts were to look next?
It should be simple: The wire between the brake light switch and multifunction switch. Use a test light and probe the multifunction switch harness where the brake light wire is. Push the brake pedal. If the test light lights up you've got power that far and the problem is in the switch itself. If the test light doesn't light up the problem is in the wire (you know the brake light switch is OK because the CHMSL works).
Ah yes, ok thanks!
ok, yes it was mostly the multi func sw. Another problem is about 3 of the wires in the connectors at the switch were out and don't stay in (plastic clip inside broken). Guess that's what happens when you use JY pigtails!
OK, glad you figured it out.