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.

bilb2765 wrote:
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.

Even a factory service manual which has some errors is better than nothing.
This will give you detailed troubleshooting instructions along with a
*complete* electrical diagram of everything. You can order a GM Factory
service manual set from your dealer or helminc.com

As to errors in service manuals, I can easily find these. It may say a
certain harness has 6 wires and each wire a certain wire color. Then when I
compare, one wire might be a different color than in the book.

Or it may say something is there which is not an accessory in that model.

But in general they are mostly correct and I can quickly see if there is an
error - then trace that wire out and make a notation in the books.



"bilb2765" wrote in message

Bill wrote:
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.

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

Pete C. wrote:
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.