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4X4 Wiring

I have seen some posts about 4X4 problems. Does anyone have some wiring info?

I have a 1998 K3500.

The 4X4 worked when I bought it, then ran into some problems with wires. Turns out, the dealer forgot to secure the main wire bundle that goes behind the engine across the top rear. It hung down on the hot engine, and fried some components. After all the repairs, (7 bad wires, new PCM/ECM, and fuel injection regulator module), now the 4X4 does not work.

I can hear it engage when I move the shift lever, but do not get any lights just below the 4X4 shifter indicating which mode selected.

I assume the magnetic solenoid is not getting the voltages needed to make it work.

Any one have any wiring info?

Thanks for any assistance.

PS. Chilton's is useless.

Reply to
bilb2765
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For a '97 K3500 at least, the factory manual is useless for this as well as it is incorrect. There is a fancy time delay relay mounted to the firewall to the right of the A/C accumulator. It has 5 or 6 wires to it, and basically when the transfer case is shifted, the switch in the tcase triggers the delay relay which sequences a syncro solenoid in the tcase and then the axle actuator motor. At any rate, most likely that relay is fried and needs to be replaced. I had one fry for no apparent reason. If you pry the relay case open you will see it's not a mechanical relay, and if it's fried you may see where the power transistor in it melted the plastic case. I recall it was like $25 or so from the dealer as none of the auto parts stores could locate one.

Reply to
Pete C.

Well, as I noted in my other post, for the '97 K3500, the factory manual and diagram for the 4WD electrical is near 100% wrong and is basically entirely useless. Certainly the factory manuals are still better than pretty much all of the after market manuals.

Reply to
Pete C.

Thanks for the info. The relay was probably fried. Will let you know what I find.

Reply to
bilb2765

Found the relay you mentioned. Chevy, for some reason is not sure what the relay part number is. There are two versions of the relay. One is $46, the other is $106. Didn't know Chevy used Dodge parts... Wish me luck.

Reply to
bilb2765

Relay fixed it. Thanks for the tip. Only problem was instead of being $25, it was $165 list. I scrounged it for $115. Thanks again.

Reply to
bilb2765

Glad you got it fixed. Oddly enough, cleaning up a pile of junk near my desk today I found my invoice from the relay I got:

Part 12182086, $65.82 from Holiday Chevrolet in Whitesboro, TX 05/07/07

That's some hefty inflation in just a couple years.

Reply to
Pete C.

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