Mazda dying when put into reverse / T56
 

This is about my FD, I know its not a Miata but im getting desperate! If its not allowed Ill understand.

I put this on the FB page and LS1tech, everyone seems to be at a loss but I'll try here.

OK I'm fully stumped and have to resort to the forum. I have a 6.0 GTO / T56 in my FD, car has been running good for about 5,000 miles.
I went for a tune last week, car made good power , runs and drives amazing. We backed the car off the lift after removing the wideband and and the car dies, ended up popping a fuse and was losing power to the ECU.
Change the fuse and all is well except now when I go into reverse the car shuts off like you just turned the key off. If we disable the reverse lockout in HPtuners the solenoid works, if I force it, car dies. Unplug the solenoid and force it, car dies. So it seems obvious to me that it's not in the electrical but I went ahead and put a new solenoid in it anyway and it still dies.
The car runs and drives awesome no problem at all no matter how cold or hot it is it dies instantly as soon as it clicks up in reverse .

does anyone have any idea what in the world is going on .....I mean how can this mechanical linkage be causing this??

There aren't too many electrical connections other than the backup lights and reverse lockout that might be causing this. As I recall, in some installs the backup light switch is real close to the tunnel. Check in the tunnel to make sure there is not some sort of short occurring when the motor torques over?

Be sure to let us know when you find the solution.

Mike

Yeah I'd disconnect the reverse lockout and see what happens if you haven't already

alright folks good news, it was the reverse light switch! Went ahead and replaced the switch and the reverse lockout since I had everything torn down to access it. The switch wiring was built into my Speartech standalone harness, all checks out there, must have been an internal short in the switch. I totally overlooked that circuit in my initial investigation, good call guys.