HELP IM GOING BROKE

[Rkbailey]

99 Silverado 4wd h light flashes when selected. I’ve changed transfer motor, push button selector switch, front actuator. I believe the only one that was actually a problem was selector switch it didn’t have the right resistance between terminals. However, no luck engaging 4wd. So, I’ve dug a little deeper into the wiring and found that a control circuit I believe connector 153 has a grey/ black from pcm #1694, black/white from  pcm #1695, and a brown from actuator, on one side. Looks to me #1694 are from pcm to tccm. #1695 s111 joins the b/w going to actuator?  And brown is just hot when ignition is on. I should back up this connector isn’t on my truck as well as pin 16,19 on red pcm connector aren’t there so I tried wiring them in with no luck. I’m not sure about #1695 maybe I got it wired in wrong there isn’t much info about the circuit and I’m not a mechanic. The truck is 4x4 it did have a 04 motor put in it last owner said wondering if the 04 pcm came along as well and was 2 wheel squeal. if somebody could tell me where to take pin 16and19 exactly or if anybody can make sense of my nightmare I got going I Preciate  it!!

[davester]

'04 computers aren't the same as '99 computers, as gm reworked the electronic system mid generation (around '03).

 

I would suggest subscribing to the full-service manual for your truck, or perhaps the gm upfitters guide for it (I don't know how much info the upfitters guide includes).  The FSM will have the wiring diagram, wire colors, connector pinouts, harness locations, and how to diagnose pretty much any problem your truck has.

[carkhz316]

Can you hear anything happening, like the whirrr/ clunk of the transfer case or the front actuator,  when you push the button?