Power window wiring

[454ssdude]

I need some help here. I’ve got a 1990 c1500 and currently reassembling the doors. I tested my windows regulators before I got too far and ran into some issues. The drivers side works perfectly. However, the passenger side does not work at all. Using a test light, I checked my switch and I am getting power to the Motor past the passenger side switch. The window will go up but but down on that side. On the drivers side passenger window switch, I am not. Nothing but a click. No signal to the regulator. I took out one of the switches that I know works and tested the drivers side switch for the passenger window and again, nothing. One thing that could be wrong is that when my wiring harness was disconnected, the pins came loose so I could have some wires mixed up. All of my hot wires light up on every switch. Any suggestions?

 

[1998_K1500_Sub]

One thing that could be wrong is that when my wiring harness was disconnected, the pins came loose so I could have some wires mixed up. All of my hot wires light up on every switch. Any suggestions?

Does the passenger's side work fine when you power it directly with test leads (up/down)? I think you said you did test it, but I'm confirming.

Otherwise... I'm gonna sound like an a$$hole here, but I suggest you get a copy of the service manual, look up the wiring diagram, and confirm that yours does (not) agree, since you have reason to doubt that yours is correct.

I think that's your quickest and shortest route to satisfaction

The manuals are available at:

GMT400 CK Service Manual Project

GMT400 CK Manual Project - The 1947 - Present Chevrolet & GMC Truck Message Board Network

GMT400 CK Manual Project The 1988 - 1998 GMT400 Chevy & GMC Pickups Message Board

67-72chevytrucks.com

 

[454ssdude]

Does the passenger's side work fine when you power it directly with test leads (up/down)? I think you said you did test it, but I'm confirming.

Otherwise... I'm gonna sound like an a$$hole here, but I suggest you get a copy of the service manual, look up the wiring diagram, and confirm that yours does (not) agree, since you have reason to doubt that yours is correct.

I think that's your quickest and shortest route to satisfaction

The manuals are available at:

GMT400 CK Service Manual Project

GMT400 CK Manual Project - The 1947 - Present Chevrolet & GMC Truck Message Board Network

GMT400 CK Manual Project The 1988 - 1998 GMT400 Chevy & GMC Pickups Message Board

67-72chevytrucks.com

Yes, I tested the leads. Thanks for the link. I’ll start digging into this.

 

[454ssdude]

Ok, so I've checked all my pins and they are correct and in the right spot. I confirmed that all of my switches work by hooking each one up to the working driver's side window as well. I also went back through the both wiring harness's entirely to make sure my splices look good and that there aren't any broken wires. Nothing looks wrong. When I'm testing the Left Switch wiring for the right window, I can hook Pink to black the test lamp lights. When I test Pink to Tan and Pink to Blue-white, it doesn't light up. However, on the other side of the door, the right (passenger) switch, I can hook pink to black up and it doesn't light up but Tan to pink does. This might be beyond me but I'm really wanting to get these doors together.

 

[1998_K1500_Sub]

When I'm testing the Left Switch wiring for the right window, I can hook Pink to black the test lamp lights.

Make sense. PINK is +12. BLK is ground.

When I test Pink to Tan and Pink to Blue-white, it doesn't light up.

You should test TAN and BLU/WHT differently. Sometimes they might be +12 and sometimes they might be GNDed, so you've got to test accordingly. I'll cover this below.

However, on the other side of the door, the right (passenger) switch, I can hook pink to black up and it doesn't light up ...

There's no BLK on the right (passenger) switch. Are you measuring from PINK to some other BLK/ground? If so, the light should light, because PINK is +12V.

...but Tan to pink does.

Makes sense, TAN should be GNDed in certain cases. In other cases, it's +12V. I'll explain. Read on...

TAN is dependent on the driver's side switch for the passenger's window, i.e., the neutral, up and down positions of that switch.

TAN is GNDed in NEUTRAL, +12V for UP, and GNDed for DOWN

Similarly, BLU/WHT is dependent on the driver's side switch for the passenger's window.

BLU/WHT is GNDed in NEUTRAL, GNDed for UP, and +12 for DOWN


Summarizing in matrix form, depending on the driver's side switch for the passenger's window:

	NEUTRAL	UP	DOWN
TAN	GND	+12	GND
BLU/WHT	GND	GND	+12

(edit See my next post. These comments above ^^^ are based on my reading of the wiring diagram. /edit)




Two really useful tools that would help you now or in the future would be (1) a DVM and (2) a clamp-on DC ammeter, or two DVMs (one for measuring voltage and the other for current). But I don't suppose that's happening soon enough to help, here.

For your or other reader's reference:

Fluke 36 clamp ammeter/DVM

FLUKE 36 AC/DC True RMS Clamp Meter with case, booklet, & leads | eBay

Find many great new & used options and get the best deals for FLUKE 36 AC/DC True RMS Clamp Meter with case, booklet, & leads at the best online prices at eBay! Free shipping for many products!

www.ebay.com

Fluke 77 DVM

FLUKE 77 HANDHELD MULTIMETER w/ BATTERY & LEADS - TESTED WORKING | eBay

<p>FLUKE 77 HANDHELD MULTIMETER w/ BATTERY & LEADS - TESTED WORKING. It’s in excellent condition, tested and working, leads show wear and tear but do work.</p>

www.ebay.com

 

[1998_K1500_Sub]

Here's a troubleshooting section from the 1989 service manual, with wiring diagram, for reference.

I believe yours is similar.

You Will Find The Problem

 

[454ssdude]

Thank you for all the help! I'll start digging deeper this weekend.