[waittslake]

hi again guys 1987 shelby charger currently has an 88 t1 blowthru setup with the log wiring and module...yeah, not my doing...lol, but it will be log again soon, i recently found out the car wont crank if the heater controls are in the off position, it has no problem cranking and starting in any other position just off. i pulled the heater controls and looked up under the dash and no wires seem to be cut/spliced into for the heater controls. the ignition switch had some splices in it for a stereo im guessing, but it was taken out and just the splice connectors are left. Everything seems to go where it should and the car will start and run. so is there any connection between the power module and/or logic module and the heater controls that im missing? any ideas are appreciated! thanks guys

 

[Turbomini]

the only way the heater controls would effect the car is if your car has A/C and it would cause the car to idle high when the a/c kicks on. but as for the crankng they might of spliced the wiring into the ignition switch to feed power but that would cause the heater to lose power during the cranking,

i will message NAJ and have him come help he's a wiring guy and he's good

 

[ChargedDust]

Once the car is running, if you switch the controls to off does the car die?

Maybe someone wired up a sneaky anti-theft device, I have a sneaky one installed myself.

My friend had a issue with his Cougar where the car would shut down when you switched on the A/C, turns out the compressor was seized, but that's the opposite of what you have.

 

[NAJ]

The only wire that is powered from the ignition switch in the "start" position is the YL wire that supplies power to the starter relay in the "start" position.
Access the ignition switch connector and backprobe the YL wire cavity with a 12 volt test lamp and see if there is power present cranking with the HVAC controls on/off.

 

[waittslake]

thanks for the quick response guys ill check out that yellow wire after work tonight and check to see if the car does die when i switch the controls to off, i was wondering if someone did just wire that as an anti theft device, if they did it certainly is effective!