Hey everyone,
Yesterday when I got in my car I noticed that my dash had a message saying to replace the rear liftgate fuse, I found the fuse and replaced it but every time the doors lock the fuse blows and the liftgate will not lock. It only blows when the doors lock and the rear HVAC system also goes out. Does anyone know what I should do to try and figure out this issue? I did purchase a replacement actuator from amazon and even though it says it fits my vehicle it looks different. I plugged it in and I still have the same issue. It's a 2005 Suburban.

 

It sounds like a short in the wiring harness to the locking mechanism. I would check areas where that harness may be getting chafed.

 

I have the trim panel off the gate and I don't see any sign of wear or frayed wires when I follow it off of the actuator. I put a 25 amp fuse in just to test it and it sounds like very little power is getting to it when I hit the lock button and still no issue when I hit unlock.

 

After digging some more, do you think it could have to do with the Rear HVAC Control Module? As I mentioned the Rear HVAC stops working when I hit the lock button after that 10 amp ECC fuse blows.

 

I’d start by checking the wiring and connectors for the rear liftgate and HVAC system. Look for any damage, wear, or corrosion that could cause a short circuit. Focus on spots where the wiring might get pinched or exposed to moisture or physical damage.

 

I've done that and I didn't notice anything
I should add that with the connector unplugged from the actuator it will still blow the fuse

 

It sounds like you have a bad ground, and the HVAC unit is back feeding into the door system.

Does the fuse still blow if you unplug the door lift AND HVAC unit?

You can get schematics on charm.li

 

I didn't try to access the rear HVAC unit which is how I am assuming I would unplug it. I am no expert with electrical-related issues so when I look at these schematics it looks like a foreign language to me. With that being said, I am handy and thought if I could find a way to track this issue down I could repair it. I already ruled out the fuse and the actuator being the issue. Now it seems like it has to be a bad ground, or I also read since the fuse also controls the rear HVAC controller it could be a short in the rear HVAC or a bad module. My problem with that scenario is that in my situation I can turn the rear HVAC unit on after replacing the fuse and it isn't until the doors lock that the fuse blows and it cuts out the HVAC, with or without it running the fuse blows once the doors are locked.

 

well post it here and maybe someone can help decipher it for you