Guys I'm having a hard time figuring out what's up with my 1991.5 tach harness. I've looked all over dtr and can't find a post about this. I looked up underneath my dash and taped to the main harness going to the fuse box was this 3 pin plug with black, orange, and red/yellow wires, everywhere I read it says it should be a 4 pin plug, so what's going on? Am I looking at the wrong thing or all 91.5's not the same harness?

 

91's back do not have the plug in the harness. Only 92-up does. When you purchased a tach kit (when available) from mopar it came with a harness. Since it didn't have a crack position sensor or a notched damper I believe the 91-back kits ran off of the alternator. I could be mistaken about that though.

 

go to TINYTACH.COM and get one that run's off the pulse of the Injector lines .

 

ISSPRO had kit with two magnets, epoxy, and a sensor that mounted on an oil pan screw. You have to provide your own wire.

As previously stated, 91.5 does not have a crank sensor from the factory.