Stereo & Electronics - Power Window... Tried it all?




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12Square
07-08-2012, 04:21 PM
I have replaced the window motor and the BCM in my car and the passenger side window still intermittently becomes unresponsive. Is there a relay somewhere, or something else that could be causing the window to stop working?

Also, I recently bypassed the VATS system and no longer have to use a chip key. As mentioned above, I replaced the BCM (months after doing the bypass). But the "Security" light still comes on and the car doesn't start sometimes. Why??? Any help is greatly appreciated!


bayer-z28
07-08-2012, 08:30 PM
Have you tried the thermal mod? What about the wiring/relay fix? From what I gather, the pass side window wiring is actually run through the driver's side switch. Maybe it's a connection problem there.

Here's some schematics for ya.
http://cs.chevroletclub.net/graphics/manuals/56/system.wiring.diagrams.pdf

12Square
07-09-2012, 01:50 PM
Do you have a link to the thermal mod discussion? I haven't heard of it. I'd rather do the re-wire thing as a last resort but will probably do it eventually anyway.


sjsingle1
07-09-2012, 03:32 PM
why would a NEW motor need the thermal mod?

bayer-z28
07-09-2012, 07:30 PM
Because even the new window motors have the thermal resistor. Mine had it and I got rid of it.

http://www.camaroz28.com/forums/general-1967-2002-f-body-tech-46/did-window-motor-thermal-bypass-omg-do-they-work-better-443785/

wssix99
07-09-2012, 09:24 PM
The thermal cutoff is there for a reason and the engineers who put it there weren't fools. Doing the thermal mod to the motor increases the stress on the door and the chances of things like this happening: http://ls1tech.com/forums/general-maintenance-repairs/961435-window-doesntt-go-up-all-way-pics-included.html

In the end, the thermal mod is a cheap approach to an already inexpensive problem with very high risks. IMO - Paying for a new lifetime warranty Dorman motor is a lot better than risking having to replace the door skin or add a plate to the door.

+1 on the ridiculousness of doing this to a new motor.

12Square
07-10-2012, 06:43 PM
Okay. I'll just get the wiring kit and give the window a direct power source. It's inexpensive enough and I've heard too many warnings about the thermal mod.

However, I know "heat" has been a culprit because the window has never worked after that side has been sitting in the sun. (With the old motor and the new one.) The old motor at least always came back on after the car sat overnight in the garage. The new motor is stubbornly unresponsive, now two days later. Really, I've used it about 10 times and never roll the window down more than a few inches, plus I got the BCM primarily to fix this, so I'm really frustrated with the whole thing.

Will the new wiring make this problem go away?

As for the security light... Is the system getting screwed up between the BCM and PCM? I'm eventually going to turn it completely off when I've got the equipment.

bayer-z28
07-10-2012, 08:47 PM
The thermal cutoff is there for a reason and the engineers who put it there weren't fools. Doing the thermal mod to the motor increases the stress on the door and the chances of things like this happening: http://ls1tech.com/forums/general-maintenance-repairs/961435-window-doesntt-go-up-all-way-pics-included.html

In the end, the thermal mod is a cheap approach to an already inexpensive problem with very high risks. IMO - Paying for a new lifetime warranty Dorman motor is a lot better than risking having to replace the door skin or add a plate to the door.

+1 on the ridiculousness of doing this to a new motor.

Haven't heard of that till now. Had it in since 07. I'll replace it eventually.

wssix99
07-10-2012, 11:07 PM
Haven't heard of that till now.

Yea, I think because people call it a "mod," we assume it must be a good thing. Whenever we take something away, there's almost always going to be some intended consequence. (This mod circumvents a safety feature of the motor, the drill mod circumvents a protective measure on the clutch M/C, etc.)

For the thermal mod, the big issue arises when a user holds the button down. This allows the motor to put prolonged stress on the motor/door. We can always manually control this by lifting up on the button, except when the express down feature is engaged. Deactivating the thermal resistor probably isn't such a big deal if one also bypasses the express down feature, so the motor reverts back to full manual control.

wssix99
07-11-2012, 06:11 AM
Okay. I'll just get the wiring kit and give the window a direct power source. It's inexpensive enough and I've heard too many warnings about the thermal mod.

However, I know "heat" has been a culprit because the window has never worked after that side has been sitting in the sun. (With the old motor and the new one.) The old motor at least always came back on after the car sat overnight in the garage. The new motor is stubbornly unresponsive, now two days later. Really, I've used it about 10 times and never roll the window down more than a few inches, plus I got the BCM primarily to fix this, so I'm really frustrated with the whole thing.

Will the new wiring make this problem go away?

As for the security light... Is the system getting screwed up between the BCM and PCM? I'm eventually going to turn it completely off when I've got the equipment.

What brand of motor did you install last time? If it isn't a Dorman, it was likely a reman motor. A lot of those do not come with a new thermal resistor, so you'll just end up with someone else's junk motor in the car - which could end up worse than the original motor you had.

The wiring kit will not "fix" anything. It just buys you more time with a bad motor. (Giving a bad motor a few fractions of a volt seems to help a bad motor perform.) Purchasing 2 new Dorman motors (100% new, and updated design) will cost you less than the wiring kits. As long as you use the shbox install method, they can be easily switched if you have any issues in the future.

If one window works and the other doesn't, I wouldn't think it's a BCM issue. If both windows don't work at the same time, then you might look at the BCM. (You should still fix that problem, though...)

WhiteBird00
07-11-2012, 08:10 AM
Getting to the VATS question... did you replace the BCM with a new one or a used one? If you got a used one, I'm surprised your car starts at all. A BCM can only be programmed once when new to match whatever key it first "sees". After that, the VATS circuit must always see that same resistance or the BCM will prevent the car from starting. If you had already done the bypass before replacing the BCM then a new BCM would see the bypass resistor and program itself to that but a used BCM would continue to look for the resistance it had been originally programmed for (only a 1 in 14 chance it would match your bypass).

You can not program VATS out with a tuner. The BCM prevents starting in two ways - it disables the fuel enable signal to the PCM and it doesn't provide a ground for the starter relay. The PCM can be programmed to ignore the lack of a fuel enable signal but the BCM can not be programmed at all so you can't make it restore the starter relay ground.

The likely cause of your security light problem is something wrong with your VATS bypass - a bad resistor or a loose connection. I suggest you redo the bypass.

12Square
07-11-2012, 08:19 AM
Yeah the one I installed is a brand new Dorman. Rivets were already drilled out when I replaced it. It will be easy to take out again. Since I don't have time to wait for the wiring kit to come in I'm going to have to try the thermal mod today... we get thunderstorms everyday in Florida right now and I have to be able to close the window! Since I never open it as far as halfway I shouldn't have any overheating problems. No express down on pass side. And if someone decides to stick an arm or head in my car... they're asking for trouble anyway.

12Square
07-11-2012, 08:28 AM
If I tune out the VATS, I can ground the starter relay manually, right? The BCM is brand new and is set to the bypass resistor - installed after the bypass was performed. I will check the connections.

Why is it that I want to blame the security issue on the stereo head unit? My car doesn't always start if the radio is off or if the driver door is open... Just curious about that theory.

WhiteBird00
07-11-2012, 02:53 PM
Yes, you could manually ground the starter relay and you could disconnect the security light wire.

Unlike many newer cars, the security system and the audio system in f-bodies are not connected in any way. However, the BCM controls the security system and it also (separately) controls the retained accessory power circuit so it's possible a bad BCM could be the source of both problems. In fact, the more you describe the problem, the more I suspect you have a bad BCM.

12Square
07-11-2012, 05:32 PM
I just replaced the BCM with a brand new one though... all of the problems are exactly the same as before.

I did the thermal mod thing today and the window still doesn't do s**t. At least I got to push it up most of the way. It'll work until I get a new motor (since I figure I've probably screwed this one up) and I'll order the wiring from Autotrix.

I prefer manual windows. Where are the details for that mod...?

heymoej
07-11-2012, 05:42 PM
we put an Autotrix passenger kit in a month or two ago on a window that would not go all the way up.......

it does now with ease.

good luck!

wssix99
07-11-2012, 09:25 PM
I just replaced the BCM with a brand new one though... all of the problems are exactly the same as before.

I did the thermal mod thing today and the window still doesn't do s**t. At least I got to push it up most of the way. It'll work until I get a new motor (since I figure I've probably screwed this one up) and I'll order the wiring from Autotrix.

I prefer manual windows. Where are the details for that mod...?

The Autotrix mod will just be throwing money away at this point. A brand new motor shouldn't need it. As WhiteBird00 points out, this seems to be a deeper electrical problem.

The window switches... are another point of failure. I wonder if the contacts on one of your switches is going bad? Maybe the heat is expanding bad contacts in a switch?

Have you tried both the switch on the driver's side and the passengers side? Does the window behave any differently when you use one vs. the other? (When you use one switch on the car for the passenger window, the electricity going to the motor flows through the other switch.)

12Square
07-12-2012, 07:10 AM
When the window was working, it operated the same with either switch. I need to test if the motor is getting power at all.

12Square
07-17-2012, 01:05 PM
Okay, so I plugged the new motor into the wiring, tested it, the wheel turned both ways with both switches, installed it in the door, the window wouldn't budge... so I loosened the bolts holding the thing in place and the window opens and closes excellent.

I recommend loosening all the bolts a bit/replacing the rivets and/or removing the bolt/rivet closest to the front of the car before replacing or re-wiring anything...

The tiny bolt closest to the door hinge was simply too tight on mine and evidently it was putting the motor in a bind. Problem solved.

wssix99
07-17-2012, 03:43 PM
Okay, so I plugged the new motor into the wiring, tested it, the wheel turned both ways with both switches, installed it in the door, the window wouldn't budge... so I loosened the bolts holding the thing in place and the window opens and closes excellent.

I recommend loosening all the bolts a bit/replacing the rivets and/or removing the bolt/rivet closest to the front of the car before replacing or re-wiring anything...

The tiny bolt closest to the door hinge was simply too tight on mine and evidently it was putting the motor in a bind. Problem solved.

Are you talking about one of the three attachment points between the motor and regulator? If so, this is geometrically impossible unless something else in the door is bent or broken.

Your description definitely sounds like binding, though. That bolt can't be the issue. The OEM rivets are just as tight as a bolt can be.

12Square
07-18-2012, 08:51 AM
It was the three bolts that hold the motor in place in the door. Maybe my door was bent in the past, or maybe I fasten things like my life depends on it... dunno. But loosening one of the bolts made the motor go from 100% stuck to 100% operational, so that was definitely the fix for mine.