20 Most Recent 2003 GMC Envoy - Page 4 Questions & Answers

Yes there is a connection with A/C going wacky and the battery disconnected for any reason, due to poor design. Upon re-connection of the battery, our actuators have a good chance of blowing. Pretty common problem, they should have disconnected Fuses #10 and #28 before hooking the battery back up.

check for a failed cat converter blocking the exhaust system

check the fuse for your rear door

There is also a relay ! FOG LP fuse # 11 10 amp location , under hood in the engine bay fuse / relay box . FOG LP relay #39 . RR FOG LP relay #45 , RR FOG fuse #5 10 amp , location rear fuse box . The fog lamp relays are computer controlled , by BCM

A vaccum hose or an electrical connector may have been disconnected during the repair. Check the battery itself by the way.

Check engine light lit or SECURITY light ?

https://s15.postimg.org/taongnt97/Untitled.jpg Click on the link, hope it works? Yes, it is a partial diagram. Check voltage and ground, see the fuses, not only check the fuses, check the fuse circuit for voltage. Use a test light. Some fuse circuits are hot all the time, some go hot with the key on. Also, check the ground, black wire with white tracer in diagram, should be chassis ground, check the way you would any chassis ground. Any applicable trouble codes? As far as your gages, the pcm sends serial data to instrument cluster telling ipc what to do with gages. I can't rule out instrument cluster itself, at the moment.

if you were told that the fan clutch needed replacing and you did not do that , then the engine light and the loss of power would be a result of overheating of the engine and it going to limp mode take it to a gm service centre for a explanation of the fault codes

check for bad grounds for the low beam relays

the fuse is located under the passenger seat on the drivers side a/c will work but no air will flow with out fuse

You shouldn't have to take out the front differential to drop the transfer case. Remove the drive shaft from the transfer case to the front differential. Then the bolts on the transmission.

Sounds like a push rod is bent. Unbolt the tube that all the rocker arms pivot on and check all the push rods.

Install a back flush kit on the engine. Connecting a garden hose to it will push any air in the block into the radiator so you can see when the air has been purged.

If it does it when idling I would suspect an IAC motor (Idle Air Control). If it is opening too slowly the added air the motor needs will not be supplied fast enough and the engine will kill.

It could be other things also but this is where I would start.

im not aware these ever had a factory replaceable cabin air filter , I did make a few inquiry's about them to some others that would know 4 sure , seems gm never installed them , but did add the frame 4 them hood back by hood hinge , there is a plastic screen there but a few companys do sell filters to replace the screens , just look on line for them I found a few with a simple google search

https://www.google.com/search?q=cig+lighter+fuse+panel+on+92+gmc+half+ton&biw=1361&bih=650&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwj_--aUpbvQAhUE4yYKHTvTBg4QsAQIKw#tbm=isch&q=How+do+I+locate+the+reverse+input+wire+on+my+2003+GMC+envoy Hope this helps

Although you may seem to have good heat, your air flow could be impeded through the heater rad by debris blocking the rad (this is the usual case for older vehicles - too bad GM didn't think to add a filter in front of this as they do with most of their newer cars and trucks). If this is the problem, getting at this rad to clean out the debris is a pain in the neck, and may require you to replace the rad or attempt to carefully clean it by removing the fan for access. Alternatively, you may have a problem with one or more of the three actuators in the system.