Can't get tach signal to work shift light or window switch
11-15-2007, 11:03 AM
#1
Can't get tach signal to work shift light or window switch I recently pulled my Mallory 685 and switched to an LTCC. Prior to the switch all of my tach driven electronics stopped working. I assumed the problem was caused by a faulty ign box because I was getting the tach signal through the box.
After switching to the LTCC I moved the tach signal wires to the white wire from the PCM and the problem persisted. I switched the wiring to the coil signal wire that now feeds the LTCC and the problem is still there.
Both the LTCC and the stock tach work fine. The car runs great, but neither my shift light nor my MSD window switch will function off the tach signal. The shift light flashes when I start the car (indicating it gets power and ground) and I double checked the window switch for power and ground.
Both the window switch and shift light get signal from a "T" to a tach signal. They both worked at one time and then suddenly both stopped working.
Any ideas? What could cause this? Where should I look and what should I test?
After switching to the LTCC I moved the tach signal wires to the white wire from the PCM and the problem persisted. I switched the wiring to the coil signal wire that now feeds the LTCC and the problem is still there.
Both the LTCC and the stock tach work fine. The car runs great, but neither my shift light nor my MSD window switch will function off the tach signal. The shift light flashes when I start the car (indicating it gets power and ground) and I double checked the window switch for power and ground.
Both the window switch and shift light get signal from a "T" to a tach signal. They both worked at one time and then suddenly both stopped working.
Any ideas? What could cause this? Where should I look and what should I test?
