Electrical issue back hatch... HELP!!!
 

Hi there,
I am wondering if anyone could help me out here. I have a 97 Blazer 4X4 with a 4.3. The issue I'm having is that the back hatch pops at certain times and I have checked all of the wiring. I will list the specific details here.

- with the doors locked, if the drivers door is unlocked (either manually or with the remote) the back hatch will pop open.
- with the doors unlocked and the transmission shifts to N or P, the back hatch will pop.
- if the doors are locked, the transmission can shift into any gear without popping the hatch.
- the button on the dash for the back hatch works sometimes but not all the time (I've yet to figure out the criteria for the button to work/not work)
- when the hatch pops with the lock there is a 6 or 7 second delay where the actuator actually holds the latch open and can't reclose, then it releases and it can be closed normally.

I think that's about it for the most part. I've checked all fuses, relays and wiring. I'm not sure what checks to perform on the actuator in the tailgate, but the wiring all looks ok. Definitely seems to be a unique problem as I've talked to 3 different Chevy dealers and they all laughed at me and said it was a good one.

Any ideas, input, possibly someone else with the same issue, I'd love to hear it. I'm at my wits end here trying to remember to keep the doors locked all the time and then having to get out all the time and close the hatch when I forget.:icon_doh:
Thanks in advanced and I'll just wait with my fingers crossed here.

change the switch in the dash, had the same problem.

Thanks, I'll give that a try. Shouldn't be too expensive, I hope.

if that doesn't fix it check your grounds

sorry Striker, sometimes i don't fully "read" the post that early in the morning (i'm 2 hrs ahead of you). i take it you're talking about pushing the rear key lock in the gate? it's part of the power lock system.
in order to your postings;
-when your driver's door is unlocked, the truck "thinks" you're still in it/using it (ie: it hasn't been locked up and left in a parking lot or something), so you can "pop" the rear window open from the outside (like getting the groceries out).
-again, the truck thinks you're still with it. when the truck is in "Neutral" or "Park", the truck considers itself stationary.
-that's the safety for the system. it considers the doors "locked", and you're not with it. also, if your truck is in a gear (not P or N), you can't open the rear window by accidentally hitting the switch while in motion. when the truck is in "Neutral" or "Park", the truck considers itself stationary. i'm not really sure why you would try and open the rear window when the truck is driving though. my '92 Jimmy was standard, and i had to have the parking brake on for the rear glass to open. same idea as being in Park or Neutral, you're not moving.
it took me a couple of weeks of driving this truck, to figure this out. when i drop off my kids in the morning/pick them up in the afternoon, i leave my truck running while i walk them to the babysitter's door, BUT i lock it up. it doesn't matter how close you are, the guy trying to steal your ride is ALWAYS gonna be closer to the door than you are! and since i have a spare door key (for all of my vehicles) on my key ring for the house/garage/shed, etc. i can unlock my truck knowing it's still gonna be there.
also, did you know that when you unlock the rear glass/gate, it also opens the driver's door too!
hope this (long winded) explanation helps you. (the orange high lighting was in regards to the switch replacement)

Tried it... no change.

Sorry for the long delay there, but I think you've misunderstood. In the list I had there, I meant that when the hatch pops, it does so without me touching the pushbutton. If I have the driver's door locked for any amount of time and then unlock it (whether manually or with the power lock switch) the back glass will pop open all by itself. If the doors are unlocked while driving and I stop and shift to neutral or park, then the back hatch will pop all by itself. The button on the tailgate doesn't work at all, and the one in the dash only works every now and then. I'm so frustrated with this now. I've checked the wiring, grounds, etc. and now replaced the switch (for that small amount of money I thought it was worth a try). It's really annoying when the very first thing you have to do before you get in or after you get out is to walk to the back and close the glass. Any other suggestions or maybe if someone could point me towards a schematic that might help, please let me know. I am a mechanic and I'm at my wit's end with this one...

You have to have wires crossed up or grounding out somewhere that is causing this. I would look at the wiring where it enters the tailgate to make sure that they have not been pinched.

Thanks for the input.

I've already checked the wiring back there and everything LOOKS fine. I've checked where the tailgate hinges, and even had the tailgate apart and checked out the wiring at the actuator. It all seems good visually, but that's why I'm trying to track down a schematic so that I can see what I should have for continuity, grounds, etc. Is it possible that it's in the actuator itself at the back? Anyone had any experience with that?

I'll see what I can pull for schematics.

Here's what I could come up with from my online references for a 2000:
http://i11.photobucket.com/albums/a1...gate_input.gifhttp://i11.photobucket.com/albums/a1...ate_output.gif