1998 Chevrolet Truck 4WD Not Engaging

CLAYDOGG84

MEMBER
1998 CHEVROLET TRUCK
200,000 MILES

Vehicle is a 98 2500. Hitting the 4wd Hi button or 4wd Low results in the transfer case engaging, but the lights continuously flashing. I checked for power at the differential and have none. Checked for power at the switch on the top of the transfer case and also have nothing. From what I understand the front differential switch is fed off of the transfer case, but I'm not 100%. Wiring all looks pretty solid with no visible burning in the loom or tight spots that could have rubbed through. I did check in a few random spots and it looks good.

4 Replies

CLAYDOGG84

MEMBER
3 POSTS

I have also checked all the fuses as well.

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Saturday, August 3rd, 2013 AT 9:46 AM

HMAC300

MECHANIC
48,601 POSTS

Scan for codes first then check to see if your encoder motor works both ways. It's on the tcase

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Sunday, August 4th, 2013 AT 5:17 AM

CLAYDOGG84

MEMBER
3 POSTS

I jumped the #13 pin on the OBDII to ground and the push button indicator light just blinks once. The encoder motor is on the bottom of the transfer case with a 2 wire plug correct? With that being said, I can hear that working but even if it were not fully functional I should still have power to atleast one wire on the transfer case switch correct?

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Sunday, August 4th, 2013 AT 6:43 AM

HMAC300

MECHANIC
48,601 POSTS

Ther are two wires but both go back to module and one or the other may supply power because it works both ways. Get it scanned auto parts do it for free then if it's got a code much easier to diagnose.

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Sunday, August 4th, 2013 AT 1:04 PM