Any luck with your no start?
I am firing this thread back up and getting back into troubleshooting this since I finally got my smog issues handled.
Anyone with new suggestions please chime in,.
Thank you,

 

Trying to get this going again as it is not starting to bug me more the more and more I drive the Jimmy. I really hate having to open and close the rear door when I get out to shut everything down, and my guess is still that this likely has something to do with the fog lights not working either.

 

Here you go (attached schematics). Should be easy to diagnose. The BCM works by putting out voltage which goes through the door jamb switches to ground. Note that the circuit from the BCM to front door jamb switch is completely separate from the BCM to rear door jamb switch circuits.

So ground the tan wire at your door jamb switch and the RAC should shut off (and dome light should come on). If so, look for a bad ground on the down side of the switch. If not, the BCM is probably bad.

Good luck!

 

Thank you for those schematics. So the issue I am having with what I am seeing there is that mine does not have any wiring to what the schematic says is the RH door switch. Just like d2dmax does not have in response 5. It seems as though there is a significant difference in wiring for those like mine who have power windows/locks/security to those with just power windows and locks.
I am not sure what your source is but does it have a specification for those with factory security?
Might you also have the schematic for the fog light circuit or the dome light control because neither of those function either.
Thank you

 

Schematic does not show any wiring to a RH door jamb switch. The only RH switch I see in the schematic is the RH door handle switch.

This is the only door jamb wiring diagram my source gives for the 4WD 2000 GMC Jimmy. It is from the factory GM eSi DVD. Note there is mention of the pickup as well as utility in the schematics, so it's a one-fits-all schematic. Maybe there is something different or additional under theft deterrent (actual alarm), since apparently that was an option.

I don't have time to look up the other schematics before work, but I will do so tonight, including the theft deterrent if it exists..

 

Note: Schematics #3 and #4 are the front/rear door jamb switch schematics already posted.

-----------------

Interior Lights Circuit Description

Power is supplied from the CTSY LP fuse in the IP fuse block through CKT 40 (ORN) at all times to the following components:

• The LH and RH console courtesy lamps
• The cargo lamp (utility)
• The dome lamp
• The inadvertent power relay in the body relay block

The inadvertent power relay is energized when the body control module (BCM) provides the ground to the relay coil through CKT 1393 (DK BLU). When the inadvertent power relay is energized, power is supplied to the coil of the courtesy lamp relay in the body relay block and to CKT 1732 (ORN). CKT 1732 (ORN) supplies power to the following components:

• The IP compartment lamp switch
• The underhood lamp switch
• The LH and RH sunshade mirror lamp switches
• The map lamps

CKT 1732 (ORN) provides a lamp request signal to the BCM. When the IP compartment lamp switch is activated, power is provided directly to the IP compartment lamp. The ground is provided by CKT 1050 (BLK) to G203. When the hood opens, the underhood lamp switch activates and provides power to the underhood lamp. The underhood lamp has a direct ground. When the sunshade mirror lamp switch is activated, power is provided directly to the sunshade mirror lamp. The ground is provided by CKT 1850 (BLK) to G202. The map lamps are provided ground when the map lamp switch is activated through CKT 1850 (BLK) to G202. The courtesy lamp relay is energized when the coil is provided power from the inadvertent power relay and the BCM provides the ground to the relay coil through CKT 690 (GRY/ BLK). When the courtesy lamp relay is energized, the relay will connect CKT 156 (WHT) to G200. This provides a ground through CKT 1850 (BLK) for the following components:

• The dome lamp
• The cargo lamp (utility)
• The map lights (when map light switch is in the OFF position)
• The LH and RH console courtesy lamps

For more information, refer to Body Control System Circuit Description in Body Control System.

 

Here's the one for the fog lights

-----

Fog Lights Circuit Description

Voltage is supplied to the fog lamp relay coil through CKT 74 (LT BLU) when the park lamps are turned on. Voltage is supplied to the load feed side of the relay at all times from the FOG LP fuse. The fog lamp relay coil is grounded through the body control module (BCM) when the fog lamp switch is turned ON. Voltage is provided to the front fog lamps or rear fog lamps (Export) through CKT 34 (PPL) with the fog lamp relay energized.

A voltage signal is also sent from the fog lamp relay to the fog lamp indicator on the fog lamp switch. The voltage signal informs the driver that the fog lamps are on.

Ground for the front fog lamps is provided by CKT 150 (BLK) for the left front fog lamp to G111 and to CKT 250 (BLK) for the right front fog lamp to G112.

Ground for the rear fog lamps is provided by CKT 1350 (BLK) to G450.

Foglamp relay control is interrupted by the body control module (BCM) when the headlamp high beams are ON.

 

Thanks again Les. I am trying to start into this troubleshooting this afternoon. All the door jam switches are new, I have tried grounding the tan in the door jam switch with no luck. There isn't wiring to the passenger door jam switch at all but opening that door still turns off the radio which is what led me to believe it had to be connected to the latch switch/actuator with the optional security system. I will trace down schematics the best I can from my laptop and see what else I can find. Thanks

 

Did you even find a solution to the multiple electrical issues? I'm having some of the exact same issues with my 1999 and was hoping you'd found a solution but just forgot to post it here. I have the same issue with fog lights not coming on (replaced switch, relay, fuse already), driver side door not turning off radio or turning on dome light (while other doors do and I've replaced the door switch w/GM part), Automatic DRL won't turn off on middle switch setting even after just replacing the ambient light sensor. Issues started several years ago when I replaced the heater core (and pulled the entire dash out to do so). I'm now in the position that the wife wants to drive the Blazer and insists that the fog/driving lights work 'correctly'. It still showing a B2647 code after replacing the light sensor. Am i doomed to have to pull the entire dash out again?

 

Sorry, I never did figure this issue out. I started having some stumbling in the engine and found my fuel spider was leaking so I started into that replacement. Never finished that either and it has been sitting in the driveway so long I forget how all the front accessory braket etc. go back on. When you say GM door switch, are you referring to the large one in the door that mounts to the door lock part that contacts the door stricker or do you mean the little plunger switches closers to the firewall?
I replaced all the plungers on all 4 doors and that did not solve the issue. I don't remember all the troubleshooting I tried but I am remembering that my last assumption was it was the large swtich in the door near the handle. The part number for this part varied by trim level, as some had power locks and windows, and mine had some sort of alarmt function if I remember right. It was not available when i was looking but it was a couple hundred dollars if it were to be avbailable. I went to a few junk yards and pulled on that looked right, but turned out to be wrong plugs.

If you haven't tried that, and if they are available and hopefully less expensive you may want to give that a shot and if it works let me know too