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Topic: HELP! Fuel pump primes when headlights are turned on... (Read 6132 times) previous topic - next topic

HELP! Fuel pump primes when headlights are turned on...

Reply #45
Problem solved. 

The cluster lights were in fact coming on, only very dim.  I checked voltage at the cluster illumination wire and it was showing 12ish volts.  The other probe i had touching ground at the frame of the car.  I then checked the cluster illumination wire with the ground probe in the cluster ground wire and it was showing like 5 volts.  I unplugged the cluster connector and rechecked and was reading 0 volts across them.  I rechecked all the ends of the ground that comes from the cluster ground.  They went various places and one of those places was a connector that was unplugged.  I plugged the connector in to its matching connector from the ground that I bolted to the firewall that is usually bolted to the dash.  Everything is back to working fine again. 

Now I have no idea how everything was working fine before.  I imagine that the unhooked ground was laying against the metal frame of the dash.  but as far as the unhooked connector, I haven't a clue because it wasn't hooked up since i did the swap.  I also have no idea how the cluster was lighting up very dimly.  I guess it was getting ground from somewhere else in the cluster? 

So anyways, everything is working fine now.  You guys were right, I did in fact blow the tfi out.  I will accept a told you so on that.  I replaced it and the car starts up fine and all lights work great. 

Thank you to everybody who commented and spent their precious time helping me figure this out, especially softtouch.
1986 Mercury Cougar - 2.3T/T5 swap, TC brakes and suspension and rearend, 3" exhaust, 255 lph fuel pump, Stinger BOV, Gillis MBC @ 18 psi
2003 Chevy Suburban Z71 - Daily driver
2015 Chevy Volt - Wife's daily driver

 

HELP! Fuel pump primes when headlights are turned on...

Reply #46
Quote from: Loaded87IROC;319711
Problem solved. 
...I plugged the connector in to its matching connector from the ground that I bolted to the firewall that is usually bolted to the dash.  Everything is back to working fine again.

YAHTZEE!  I knew I experienced that same queer scenario you were describing! Glad it you found it!