Power Window Diagnosis

[C-5-4-3]

In the middle of a 50 mile trip in my C4, both power windows quit working simultaneously. I checked the fuses but all seem OK. How do I start diagnosing this issue?

Thanks for any help here.:confused

 

[shark454]

Does the motor still spin( can you hear it)? If so, you have a motor gear or window track issue. If you cannot hear the motor spin, the brushes could be worn away.

 

[C-5-4-3]

No, either driver or passenger switches are working. When I had the ignition off, the passenger window worked once. After I started the ignition, neither side worked at all.

 

[shark454]

It has to be electrical then. Measure the voltage to be sure. Fuses can look good and still be bad, test it with an ohm meter.

 

[Hib Halverson]

It is highly unlikely that both window regulator motors would fail simultaneously, so my guess is this will be a troubleshooting exercise with wires, connections and fuses.

The first thing you need is the factory service manual and its wiring diagrams and component locator information.

I'd be looking for a problem in the power feed to the power window wiring before it splits to feed left and right. Don't rule out a fuse that, on first glance looks good, but is actually faulty. Additionally, you may want to look at how the pwr. window sys. grounds. If grounding a single point for both sides (unlikely but possible), that could be a problem, too.

Are there any other electrical subsystems in the car which are also troublesome?

 

[C-5-4-3]

Thanks for the info. The manual is describing the DAB or delay action relay. The series of tests is from the point of view that there is no delay. If tests fail it suggests the Central Control Module.

I checked the circuit breakers as the power windows apparently are fed through the 30 amp breaker. They all test ok as far as continuity.