Power Window Relay HOT. (+more)

[exitwound]

How hot is too hot? Only the power window relay and none of the others is exceptionally hot, so hot you can't touch it. We feel this might be out of the ordinary. Of course it's only hot when the car is running and cools when off. Should it run hot?

Also, we're investigation the car not starting after running 30-60 minutes. We have an idea it might be a drain on the battery due to the alternator not working, or the regulator brushes being worn. But in any event, would a relay running hot (for whatever reason) be the cause of the battery drain?

[ilikemy944]

Hmm, mine, and only the window relay, gets real hot too. I haven't started to diagnose yet.

[SoCal Driver]

Check the voltage at the window motors. You may have a stuck window switch. Note there are only two wires that go to the window motor from the switch. You can check these at the back of the switch.

[exitwound]

Alright. Sounds like a plan. Both windows work by the way, and work well, both up and down.

[ilikemy944]

Mine as well.

[exitwound]

How much of a chore is it to remove the switches? Do you have to take the door panel off?

[ilikemy944]

Two screws in the bottom of the little plastic piece holding the switches. They then just pop out.
2 minutes.

[Gemni911]

Been working through several electrical problems on a 1988 944. We are exeriencing the same VERY HOT window relay and are going to check the window switches later today. The relay has a large wire wound resistor in the top that is generating the heat. The 30 terminal (batt voltage) is hot and I worry about the heat damaging the connector and wiring under the central electric board (seen this before on late 944's). Windows work fine and don't hum or anything else. Will check each side with the switch disconnected and then check each side after reconnecting the switches separately as well as closely examine the switches.

[Bukowski]

Just found this thread - what is the window regulator relay so hot for? My crude investigation shows the resistor (or the cylindrical object inside) is the heat source, and it says "105 degrees C" on the wrapper. Is this normal?

I ask because I am troubleshooting window problems... etc... BTW I cleaned two of the three switches and lithium-greased the regulator where I could reach it. Rennbay has great videos to show how to remove as well... but I don't know the voltage at the motor, nor if the switches are actually any good even though I cleaned some.

Also - just had a cup of coffee, hence the enthusiasm.

[Tom944]

I would guess that the resistor shunts the power if you keep your finger in the switch too long. Therefore if it gets hot all the time it is possible that the switch, or even the relay contacts, may need cleaning.

[ilikemy944]

Wow a thread I replied to in 2007. To cover that, I have no idea what the cause was and I never investigated it further. Pretty sure that was my old n/a 944, which I sold to a neighbor. Never had any issues out of the windows.

[Bukowski]

Can you check if the new relay is hot?