Texas07Sub

I recently bought a 2007 Suburban with a non-operating back lift glass. The owner said he had a "garage" look at it and replace the acculator but still couldn't get it to work. Didn't really mind since the liftgate door works fine. Well rear wiper stopped working. found a blown fuse. Few days later same thing. I took the liftgate back panel off ... low and behold the connector for the window accuator was completely cut off. (4 dangling wires) I tested the acculator and could get it to engage with battery voltage. So two things .... 1) are these (lift glass and rear wiper) on the same fuse? 2) What is the wiring diagram for the connector. After some further investigation, the only solution Chevy has is to buy a new liftgate wiring harness. I would like to buy some pin connections and wire it up myself to make sure there isn't a bigger issue. if someone can give me the order of wires that would be great. Cheers.

in2pro

Welcome to the forum

I don't have my manuals available to me at the moment... hopefully someone else can respond, if not I will take a look this evening and see what I can find...

You might be able to use a meter to find out which ones are ground and which one is power by having someone activate the button on the key fob for the back glass...

intheburbs

Yes, they both appear to be on a 25-amp fuse in the IP fuseblock labeled rear wpr fuse 25a.

Regards to the wiring diagram, I'm not going to post it (copyrighted material), but it's page 12-55 of the Haynes repair manual #24067. It was the first thing I bought when I got my 08 Burb.

Texas07Sub

Regarding intheburbs comment, can you tell me the order of the pinout for the 4 wires. Going from memory there was a red, black, brown, and one other maybe yellow/black strip. I might be confusing some of the wire colors with my sons '71 mustang we are rebuilding. since it is a straight connector I just need colors filled in:
1 -
2 -
3 -
4 -

If you can help that would be great. or take a picture of the connector if someone has opened up their liftgate.

cheers,

in2pro

Sorry for the late reply give this a look



Pin
Wire Color
Circuit No.
Function

1
L-BU
6795
Liftglass/Trunk Motor Release Control 2

2
BK
1450
Ground

3
BK
1450
Ground

4
PK/BK
1303
Liftgate Ajar Switch Signal (E52 Except E61)

PU
2279
Liftglass Ajar Switch Signal (E61)

Texas07Sub

Thanks for the pinout. Ok here is the status. Grounds are good. Checked window ajar sensor. Checked window release button on door at connector. Checked the accuator by using the 12V charging outlet and jumping the middle contact to pin #1 where the the light blue wire terminates. By pushing the button on the FOB nothing happens. By pushing the button on the door nothing hapens.

Problem I see is that I have 12V at the light blue and 12V at the ajar sensor all the time but the accuator is not moving. What am I missing?

Couple of questions:
1) why would there be constant 12V on the light blue wire (pin #1)?
2) Is it possible that there is not enough current to engage the accuator?
3) Does this indicate a bad BCM?

warthogcrewchief

Don't buy a whole new harness. I was told the same thing when I purchased a used '91 GMC Sonoma (S-10) that had a lot of wire "damage" from some electrical genius. Instead of buying a new harness, I went to one of two local junkyards and clipped the wires and connectors I needed. I got three plugs + wires for $10. I then literally matched the wire colors up, soldered the wires and insulated with tube heat shrink.

peennie

My lift gate glass opens when remote starting, and sometimes when opening a door or back hatch. I have reprogrammed both key fobs with no luck. Any suggestions?? It is an 07 suburban, have had for 2 years and this just started.

in2pro

Welcome to the forum...
I would suggest opening up the remote and cleaning it, and inspecting for any moisture or damage to the circuit board... make sure the button press is not also activating the rear lift glass contacts at the same time...
Is the button rubber still pretty supple or is it worn and maybe collapsed?