4x4 solenoids question

NeXuS1 · May 21, 2002

lately everytime i shift into any 4 wheel drive mode (4high, 4low) its been blowing the 25amp fuse in the cab of the truck marked 4x4. we've traced the problem down to the two solenoids in the front differential. so the question is, how hard is it to change them if we can even get at them at all? we cant even get to the solenoids to check with a multimeter. so i assume it may be something we have to take in to get done. i need my 4wd back before thurs when i'm suppose to leave for sand mountain. so if anyone can help that would be great.

bassdog · May 21, 2002

I'm not sure if you can get at them Nexus. I have looked at mine while changing my oil and it looks as if they are inside the housing. This may be one thing you want to take in to get fixed.

NeXuS1 · May 21, 2002

thats what i was thinking, but had to check first. the truck is in today getting the brakes done. since i don't have the time to do it my self. plus the rotors weren't looking too happy. so guess next i have to find a place to take it to and see what it will cost me.

NeXuS1 · May 21, 2002

does anyone know if the solenoids are of a "push pull" type? i realized that when i did the testing last night it was into 4hi alone. but my dad thought maybing 4low might still work, but dont want to test that yet because he thinks it might get stuck into 4low then.

hopefully someone understands what i said.

May 22, 2002

What solonoids are you talking about? I have a '95 and was under the impression that the only electrical device was the thermal actuator. If you are laying on the ground in front of the truck, it's on the upper left side of the front axle center section. you just screw it out and screw in a new one.

NeXuS1 · May 22, 2002

i was told they were solenoids. so thats what i went with. is it possible that theres the thermal actuator and a sensor of some kind? if not then why is there 2 plugs?

May 22, 2002

Do you have Electronic 4x4 shift? I was thinking of the front axle only, I shift the transfer case into 4x4 manually. Sorry if I got you headed in the wrong direction.

NeXuS1 · May 22, 2002

it has the shifter on the floor. its just impossible to see anything up past the axle. so i can't really tell what the things are plugging into. but it is part of the problem. whatever they are.

NeXuS1 · May 22, 2002

finally got some decent light and traced the black wire to the unit screwed into the diff. pulled it out. did a little check with 12v and it didnt do anything, checked it with a multimeter, its shorted. so i should be able to make a trip tomorrow pick up the part (hopefully its in stock somewhere) and put it back in.

glad it wasnt something too hard.....

Bob G. · May 22, 2002

Chevy and GMC dealerships replaced a lot of those thermal actuators here in Vermont from 88 thru 97. It took a long time to heat up the actuator when it was -20 F!! And, it didn't usually snow in the summer when it would work the best! GM replaced the thermal actuator with an electric solenoid around 98. I bought one for my 88 GMC when I still had it. It screwed into the original front diff housing and had to connect up a couple of wires. It worked way better than the original actuator.

May 22, 2002

I hope I sent you in the right direction. Mine quit about a year ago and I still haven't got around to replacing it. In Florida, there isn't much need for a 4x4 crew cab...