Update: drivers door window switches lights flashing

[pilsburypie]

Firstly apologies, this is not a double post from my previous one, just better info as I have now driven my car in the dark and my last thread now seems a bit misleading. Car is a 2011 V60 drive

So, on the drivers door where you have all the window controls, the wing mirror controls and also the door locking/unlock buttons, the backlight flashes on and off slowly every 2 seconds. The window switches only work when the lights are on for the 2 seconds, then stop working during the 2 second off. Lo and behold, 2 seconds later when the backlight comes on they work again..... and so on.

What can be wrong? The switches obviously work, they just have this alternating power on and off. Damn car went out of its 3 year warranty in November. Typical.

[taylorc]

It definitely sounds like a power issue, maybe a relay?

[pilsburypie]

I'm not great at this sort of thing , but I would say that is the likely area. On more testing today, the nearside passenger windows work fine, but it it he drivers side front and back that work intermittently. The flashing on and off of the power is weird.

Any idea where the relay is for the windows? A real shame that there is no Haynes manual or similar for the V60. I have done almost everything to every car I've owned with those books and very little skill!

[pilsburypie]

Just spoke to Volvo and they suggest it could well be a failed drivers door module (DDM). Now I have read about this on the net and i't not really a part you can just buy and fit as it needs some software update to match it to the car or something along those lines.

Volvo recon close to £200. 3 Year warranty ran out in November. Nothing wrong with the car for the first 3 years, then Bam, 2 months out of warranty........

[Lamp Swinger]

Can you not hear the relay clicking, so you can locate it, with the engine off naturally?

David

[pilsburypie]

Not really, no.

[PeterX]

Hi,
Did you find the root cause? I had same issues two months until my battery dropped to 8,5 V over night (no idea why). Road service came to start up the car and before start up they had to ”reset” the computer by taking the plus away from the battery for few minutes. Aftet this problems went away. Before this, about one month ago, I had a few messages about low battery (battery was two years old). At the battery store they tested the battery and said that this is pretty much like new one => no need for change. Also, charging was working.

So, to get rid off the driver window problem and flashing leds the ”reseting” seemd to be the medicine. However, I think the root cause for the whole thing (least in my case) is with charge level measurement circuit and earthing wireharness, because it seemed to be quite badly corroded. I’ll order new minus wireharness tomorrow. Lets see what happens.

My theory is that if the wireharness’s wires or connections are corroded there will be offset on charge level measurement and computer gets too high cahrge levels from measurement circuit. In this case battery will run with way too low voltage level. Once you drive a lot of sort distances (like in my case) or there is much of a load (summer just came and need for air condition came) the level drops and driver side control unit doesn’t get enough operating voltage. Just a guess and let see what is happening once I get new wireharness for batter’s minus. I’ll post the results after few weeks

[PeterX]

So, update for my previous message.
After booting the computer by removing plus wire from battery for few minutes, replacing the minus wire with measurement unit and clearing the fault log everything works perfectly. No window problems or low battery messages. And battery is the same two years old.