HMMWV won't start

[Sisu]

This forum has been super helpful in getting my HMMWV going. A new problem has arisen that has me stumped. To get my rig rolling, I've replaced the pcb with a new version, batteries, glow plugs, and grounding wire harness. Not a single problem for a couple of weeks. Ran like a champ. Then one day I went to leave work, and it wouldn't start. When I switched the ignition switch to the run position, the wait and brake lights flashed, and then nothing. Wouldn't turn over, the headlights don't come on, nothing. So I checked the batteries, and they're great. Fully charged. I rechecked all of my connections, nothing jumps out at me. So I ordered a new ignition switch from Kascar, plugged that in (after disconnecting the battery), and nothing. The same thing happened. The wait and brake lights flashed, then nothing. I've searched everywhere I can think of to see if this has happened before and have come up empty.
Anyone have an idea what my problem might be?
Thanks

 

[gcbennet]

Odd that the brake light flashed. The wait light will flash if the S3 box senses something wrong.

 

[bikeman]

I know this sounds basic... but are you sure it's in Neutral (or Park)? It won't (shouldn't) start if the transmission is in gear...

 

[Sisu]

Ha. You must know me! Though it tends to be a gift of mine to overlook the obvious, I did check to make sure it's in neutral. Is there a sensor that could be bad? Wouldn't the lights still work? I'm clueless.

 

[Dock Rocker]

There is a neutral safety switch. It can be bypassed for diagnostic reasons. It's just a ball switch with two wires.

 

[Sisu]

Me and my mechanic disconnected the battery and checked every connection we could find. hooked the battery back up and still nothing but the flash of the lights. With the ignition switch in the run position (nothing working) we flipped the light switches on... and BAM, everything seems to be normal again. Even works after I installed the old ignition switch back in. I'm not sure what was wrong. Thanks for the input. I'll let you know how it goes. Peace out.

 

[1 Patriot-of-many]

Maybe you guys monkeyed around enough to make a bad connection somewhere good again...... I hate when things fix themselves, cause they'll unfix themselves at the worst moment!

 

[Dock Rocker]

One thing you can count on is mechanical things never heal themselves.

 

[Retiredwarhorses]

Me and my mechanic disconnected the battery and checked every connection we could find. hooked the battery back up and still nothing but the flash of the lights. With the ignition switch in the run position (nothing working) we flipped the light switches on... and BAM, everything seems to be normal again. Even works after I installed the old ignition switch back in. I'm not sure what was wrong. Thanks for the input. I'll let you know how it goes. Peace out.

not entirely uncommon....I would source a new light switch and have it ready.

 

[cq141]

i want to install the ignition switch to my Humvee does anyone now the wiring sequence

 

[Dock Rocker]

There are plenty of plug and play ignitions. Look at those military guys or the big auction site.

 

[darr3239]

So after buying a bunch of different parts, now I hear about The Military Guys' low prices!