Starter, nss, ignition issue

[sefiroxx]

04 Sierra auto. Starter has become intermittent.

 

Occurred first time after sitting for 4 hours Texas heat. Fortunately, had meter etc on truck to diagnose. Found no power to solenoid. Tried:

- swapping relays, no change

- tried shifting the gear switch to reset nss, no change

- had to jumper power to the solenoid at the fuse/relay socket. (Now have a jumper wire laying in the box for when this happens periodically

- 12.6v on battery, 14+ when truck is running. Battery is 10 months old

- 01 fsm shows power from battery to fuse to ignition to NSS to relay to starter.

- have not climbed under to see if power is coming from ignition switch yet, figured I'd post first as I need to track down a helper.

- truck starts fine immediately after jumper wire

 

Here's the odd findings that might suggest

- truck is drive by wire

- steering wheel has not locked up in a while (1 year?)

- tried last night, jumper did work but headlights would dim when trying the key. Had the jumper wire (bypassing relay), thinking battery might be weak, turned off the headlights with jumper in and key to run and truck started immediately (had to run quick to pull the jumper to disengage the jumper)

- problem seems to occur after environment changes (cool down, rain, sit overnight)

 

I'm thinking ignition switch but would like see if anyone else had similar.

[Supreme Pizza]

I would definitely look at the ignition switch.The plastic cover surrounding the steering shaft / ignition switch comes off with a few screws on the bottom. Then, one of the large wires is the starter (solenoid) wire. If that wire is not hot while your cranking, then its almost 100% the switch. I suppose its possible that you are not getting power to the switch, but I doubt it. I can get ya the wiring color codes if ya need, let me know. 

 

I just had mine apart, while I was installing a remote starter. If the switch is bad, you could (theoretically) connect a cigarette light power plug to that solenoid wire, and start it that way - but a replacement ignition switch would be a much better option obviously. 

[Supreme Pizza]

 

 

$17.28 

 

 

https://www.amazon.com/Dorman-924-715-Ignition-Starter-Switch/dp/B00GJ1JC08/ref=sr_1_2?ie=UTF8&qid=1528152898&sr=8-2&keywords=2004+sierra+ignition+switch

 

 

 

[Rosco]

If the switch above does not fix the problem try replacing the neutral safety switch. I tried everything else and replacing it fixed mine. 2005 GMC sierra.