Hey guys, I'm new and my first post and just had a problem. I just picked up my 1988 humvee m998 and starts fine. I put new batterys in and still started fine. Then I installed a key turned ignition switch and now it won't start. Installed the old switch and won't start. Then wait light turns on and then nothing after that. Any ideas or anyone come across this problem? Thanks

 

You could have mixed up the wires on the switch. Just unhook the wires and start over. The only 24v power wire goes to power in (supply- however it's labeled). All the wires except the starter signal wire should go to the ign switched power and the starter signal wire oviously goes to the start/crank position then to the starter soleniod. If that does bot help i can get or draw a wiring schematic for you.

 

To hot wire the simple stuff just connect all wires at the ignotion together( you can use a paper clip) except for the starter signal wire, then just touch the signal wire to power momentarily and it should fire up.