Hi all,

Tonight I found that when I press on one or more of the powerwindow switches my lights dim and the cars idle goes down! This doesn't seem normal (at least the idle change) and I can't seem to find anything about this in the 700/900 FAQ.

Any thoughts?

Thank you in advance!

Best,

Angus

Wow!, thanks for all the great responses. My battery is old (almost 6 years!) so I am in the process of replacing and will see if that has an impact. The battery was showing signs of age and a drop in its ability to hold a charge. After 2 hours of running the radio while working I had to recharge the battery. Still cranks pretty well but I think it is time to make the switch.


I'll let you know.

Thanks again!


Best,

Angus

This is perfectly normal. We have known this for the past 18 years on all our volvos. You don't have a short, don't worry.

96 960 , 103,000 miles and running strong.

That is normal. The stalled rotor current of the window motor is high since no Counter Electrocmotive Force is generated by the stalled motor. Since the engine is at idle and the alternator is turning slow, the alternator can't put out as much amperage as the window motor requires and the battery has to provide the extra electricity which the alternator cannot at engine idle speed.

This is normal. Yes, your car is aging and the alternator and battery outputs could be lower than when the car was new.

I agree with this, but the implication is then, is it not, that if sit there with my engine running opening and closing my window like there is no tomorrow, at some point the engine will die on me.. or is my logic on vacation?
--
George Holmer, Belgium, Europe, 1987 745 GLE Turbo Diesel Intercooler (D24TIC/M46) 200k; 1988 745 Turbo Intercooler (B230FT/M46) 290k; 1988 745 GL (B200E/M47) 190k

If the battery is good enough to start the car, it would take a very long time to draw the battery voltage down to where it wouldn't run the ECU and fuel pumps with the alternator doing as much as it could at idle.

I think you would probably toast the power window motor before you would run out of battery voltage. Power window motors are not made for continuous duty.

What is the pertinence of the question to real world car maintenance?

check the battery if it is significant drop

ubhi

Affects it by how much? If it's a significant change, then no, it's not normal. If it's minor, it's normal. You're putting load on the alternator.
--
Kenric Tam
1990 Volvo 740 base sedan (B230F)
My Volvo 'Project'

You have a short to ground.

Have you checked the voltage with engine off, then on to see if it's charging correctly?
--
-------Robert, '90 240 wagon, '84 240 diesel , '80 245 diesel