Hello, I've got a 1991 jeep cherokee laredo, I'm having an issue where the engine just shuts off most of the time when I hit the turn signal. And when it's flashing, It will prime the fuel pump, and the dash lights, clock and radio flash with it. Not all the time though. Brake lights and hazards lights are also not functioning. And sometimes I will have to wiggle wires under the dash to even get power to the ignition. All the bulbs, sockets, grounds are good. Brake light switch, turn signal switch, flashers have been replaced. I'd also like to add that there is a humming coming from the ecu whenever the signals are on. I haven't been able to find corrosion or bad wires without digging too deep into the harness. Any ideas on where to look or where to find the culprit? I'm completely baffled.

 

How do the fuses and fuse terminals look? Corroded?

 

No blown fuses and no corrosion. There were a few cheap fuses that looked white and were slightly cracked.

 

Classic bad ground symptoms. Start cleaning them up. http://cruiser54.com/?p=19

Start with your main battery cables. All 4 of them, both ends, and don't be gentle with the cables when you are checking them. Yank them, pull them, push them. Corrosion can wick up inside the jacket and do a lot of damage without being obvious. If they are bad in there, you want to break them so that you know where the problem is and you can fix it.