I had a tranny shop test the transmission with his controller, and he said it shifts fine when hooked to the controller. Told me to change the ignition, but was wondering if there was a way to jump a couple wires to test the theory. any help would be appreciated.

Answer: Not sure why he would have told you to change the ignition switch. the only thing i can think of is that he suspects that the ignition switch is intermittently not sending full voltage down to the shift solenoids.

This is a problem we have seen on some trucks. It can cause low voltage to the transmission or any other circuit.

Depending on your make and model, there may be an area to check for a corroded wire, connector or broken wire. Some Chevy and GMC trucks have an area on the passengers side of the rear of the engine where the harness that goes down to the trans rubs through. Another spot where wires break is in the large connector on top of the drivers side fender well under the hood. The connector right on the transmission has problems getting corroded and turning green.

Running your own wires or something like that would need to bypass any wiring problem after the ignition switch. But without knowing exactly where that is, you could not even guess where to start and end the wire.