Another window relay/power question

[tim182d]

i know this topic has been covered repeatedly on the forum, as I've searched extensively and reviewed many threads, but I'm still stumped.

Working on my '85 911 Cab. The power windows work all the time. Door switches work well, as the interior dome light works properly with doors open. I understand that the power window relay has a timer, but it never seems to let go. I ordered and installed a new power window relay from our host. No change. Seems the relay remains powered. The only way to unpower the windows/relay is to either pull and reinstall the relay, or disconnect the battery.

I'm told the car had an after market alarm that was removed by the previous owner...perhaps related?

What am I missing?

[cabmandone]

Check power to the relay coil see if it's losing power once the key is off. My guess is no and that someone hot wired the relay.

[tim182d]

Thanks cabmando, but I rechecked and no such luck. Pin 86 per the diagram is the switched one and it switches with the key just as it should. Pin 30 is always hot.

Any more ideas folks?

[universeman]

I'd grab a trouble light and start tracing backward from the switch & relay, looking for current, if it were me. It's going to be a pain, but somewhere you're going to find a t-tap or something that's not supposed to be there.

If you pull the fuse does it kill the power? If so, that means your trouble is that you're on a different circuit than the intended one (maybe the clock circuit or something.)

[Smoove1010]

I just went through this and I documented it here: Battery Drain in 87 Cabriolet (Or Not?) and here: Power Window/Power Seat Circuits Crossed?

In my case I found that the power seat and power window circuits were crossed. I believe this was the result of my car's wiring being replaced/molested at some point along the way, so you could be onto something if a PO was "fixing" wiring when removing an alarm system.

My windows worked all the time even with the key out, and even with the power window relay disconnected!

Have you tried disconnecting fuses one-at-a-time and checking window function? In my case I had to disconnect fuses 1 and 2 on block one simultaneously to stop the windows from working. While I was at it, I also solved my fuel-pump-always-runs issue.

I got some great assistance right here on the forum, so you've come to the right place...

Good luck,
GK

[86 911 Targa]

Originally Posted by tim182d

i know this topic has been covered repeatedly on the forum, as I've searched extensively and reviewed many threads, but I'm still stumped.

Working on my '85 911 Cab. The power windows work all the time. Door switches work well, as the interior dome light works properly with doors open. I understand that the power window relay has a timer, but it never seems to let go. I ordered and installed a new power window relay from our host. No change. Seems the relay remains powered. The only way to unpower the windows/relay is to either pull and reinstall the relay, or disconnect the battery.

I'm told the car had an after market alarm that was removed by the previous owner...perhaps related?

What am I missing?

Aftermarket alarm is a good suspect.

The system is designed so that the windows are still operational after the key is off until the door is opened.

Opening any door should disconnect the power window circuit.

Good luck,

Gerry

[tim182d]

Thanks for the ideas. I'll try some of this. For what it's worth, pulling fuse #1 does kill the windows. Also, if I pull the relay and plug it back in the window circuit is cold. It's as though the relay is stuck on. As I said earlier, however, I did try a new relay. With no change. I will trace the door switch wires back to the relay next.

Sorry, I'm an amateur, in learning mode, and not near the car this week so my testing will be delayed a week, but thanks for the ideas!

[tim182d]

Thanks for all of the ideas and references! Turns out the door switch (ground wires) that connect to the 85b pin were in fact not connected to the door switch circuit. They were "dead" so to speak. No current and no continuity to ground. I was unable to trace them and assume they were cut at some point when a PO had an aftermarket alarm installed or removed. In any case, I found the correct door switch wires and tapped in a jumper to 85b. Works perfectly now and no ill effects on anything else.

As an aside, upon completing that work I discovered my A/C system was inop so naturally thought perhaps there was a connection of some type. Turns out a relay was fried and the problem was unrelated.

Thanks again to the folks who offered help!

Tim