Well guys, when it rains it pours! Some of you will already know about the problems I have been dealing with in the last week, with the HPOP going out and all, well..... I just brought the truck home from the garage ($1450 later) and decide that I will pull it up onto some truck ramps so that the front of the rig is elevated and it will let any oil still up in the valley of the engine, any oil still laying on the transfer case and fuel tank guards and anywhere else it may be hiding to run downhill and off the truck, you know kinda a lazy mans undercarriage clean! Anyhow, I go to put the rig in 4X4 to pull onto the ramps and guess what, no 4X4. Screwed around with it a while and all of a sudden it pulls into 4-low and stick there, will not unlock for nothin'. I finally end up taking the motor off of the t-case and putting it back into 2 wheel drive manually. Now, before I wasted anyones time I did several searches on this issue and read till my eyes were sore, BUT, most all of the troubles were with folks motors, they could hear there relays clicking but the motor was doing nothing..... in my case my relays aren't even making noises, I don't think power is even getting that far, any good ideas on this wonderfull issue? Signed, frustrated in Indiana. lol

 

Bad relays? Fuses also, but they are bad or good. If they were blown, it would never have pulled in at all. Is your's ESOF?

 

M.J. is the hubs ESOF? there is a troubleshoot step to check if theres a leak... i think its cut the vents on then try to engage 4wd and if the air switches to defrost you have a problem with the hubs(vacum)... guys correct me if that step is wrong or not

 

I think that only works for the vac part of the system, Steve. MJ have you checked the fuses for the switch to see if it has power to the switch? If you have power to the switch then maybe the switch has gone bad or there is another wiring issue between it ( switch ) and the relays and motor.

 

Thanks for the sugestions. So far I have checked the fuse (if there is only one), that'd be #17 in PDB under the hood, and also replaced both relays, I was unable to find a wireing schematic for the system. The first relay that I tried was the wrong style and it blew the fuse as soon as I started to plug it it, I'm really hopeing that it wasn't enough to fry something else in the split second before the fuse blew! Not sure where to look, It was not acting right before that incident, hence the new relay, but after that it never offered to work again, I'll have to look into where to switch gets power from, and whats this about the GEM, not too familiar with that, is it all good or all bad, or can parts of it go out? In other words could the ESOF circuit go out, but the power window circuit still be OK, or......? Keep the ideas comming boys, it's 33 degrees out this morning and I'm afraid snow's not too far away!! P.S. Yes, it's that pos, ESOF set up (worthless), and the vacuum test turned up OK, definately seems to be in the power side of things.

 

IIRC Ben had a similiar problem to yours. Try to have someone turn the switch and check the voltage down by the shift motor. Might also want to pull the dash off and check power at the switch itself. While you check power there you could do a continuity test on the switch itself. Glad I have the lever on the floor after seeing what you guys have to go thru sometimes.

 

If the indicator light is on, above the esof, with the truck running, put it in neutral, hold the brake, and switch to whatever you like. Wait a couple seconds it should go. If it infact doesnt, just let off the brake a little, and allow the truck to just barely coast. Sometimes thats all it takes. I do realize theres a chance, its an electrical problem, but sometimes its just as simple as what I said. Good luck

 

i agree some times it just may take a nudge to get it to engage.. i know mine is kinda wierd about going from 4hi to 4low.

 

Thanks for the replies guys, believe me over the weekend I tried any which way in the world to get this thing to budge.... no go, like I said it's not that the motor is having a hard time making the engagement it's that the relays arent even clicking trying to send power down to the motor. I will have to get into the dash and check for power in there, right now it's to work before daylight and home after dark, so it's another job that will have to wait till weekend, but keep the ideas coming so when I tear into this ole' girl I have lots of things to check till I get it figured out and working, I'll keep checking back as time allows. Thanks again..... Oh yeah, any info on the GEM? Still don't know too much about it even after some searches.

 

I'm going to say this just for the record.

4x4 HIGH can be engaged and dis-engaged in neutral or park, with or without foot on brake.

4x4 LOW can be engaged or dis-engaged only in neutral with foot on brake.

That is the way my ESOF works.

 

Good point to remember Robin, Hey, has anyone had any better luck than me finding a wireing schematic for this ESOF circuit? I can't find one anywhere. And still looking for more info on the GEM (where it is, how it works, how to test it, etc.). Thanks guys.

 

Links To Work Shop Manuals by Year CLICK HERE

My PC takes awhile to load this stuff and it doesn't look like anything is happening but patience pays off.

Use Alpha Index to find Four Wheel Drive Systems.

Hope this helps.