So while responding to a fire call tonight the truck popped a fuse to the park lights/dash cluster. I think the mechanic must have messed up the wiring to my headlight flasher when he had the cab off the truck to replace the engine. So after the fire I replaced the fuse and the lights worked fine.

When I was leaving the scene the truck started bucking like it was in 4wd High when the wheels were at full turn. The ESOF switch was in 2wd. I turned the switch to 4wd High and Low and the dash 4x4 light did not light up. I don't hear the vacuum pump running so it doesn't sound like there is a leak. The A/C switches from vents to defrost just fine.

Any ideas on where to start looking?

Thanks.

 

well, it seems like your hubs are locked and you have no response at the transfer case. Maybe check the transfer case plug. Could be abother fuse blown as well, I can't remember which one the ESOF is on but someone will chime in. The hub issue is minor, you can always get by by manually locking but if the t-case doesn't shift your SOL. If the tcase is plugged in I'd check the switch on the dash, it's kinda weird to check electrically, theres no open or closed, it just has different resistance values for the different positions. Wow. Long sentance. Easiest way to test is to plug your switch into someone elses truck and see if it works.

 

Hmm ok. I will go check the transfer case plug. I also noticed that when I turn the key on the 4x4 doesn't light up like it normally does with the rest of the warning lights. The ESOF fuse is good.

 

Just to follow up. I went out and checked the plugs @ the transfer case. They appeared to be good and snug. I got back in the truck and switched the ESOF switch to 4wd High. I did this with the truck not running so I could listen for the little motor to kick the transfer case into 4wd. I heard it turn over about 6-7 times and then it stopped and the 4x4 light lit up on the dash. Turned it to 2wd, motor turned over once. Back to 4wd, turned over once. So it looks like it's fixed now.

I also heard the vacuum pump running for a minute later on last night when I started the truck. Now I'm starting to wonder if it is vacuum related.