Help me solve 2 problems on my P2 V70 D5

[rocknotdead1994]

Hello, could any of you guys help me solve these problems on my 2003 V70 D5 auto?

1st problem would be rear power windows not working from any of the switches.

Front power windows work just fine, but the rears don't. They died over a year ago and I haven't found a solution (I wasn't looking for a long time). The strange thing is that one of the windows died about a week after the other.

I took my car to an car electrician and I was told my window motors were bad, but after a while i tested them manually from a battery and they seem to work.

When I click on any of those switches I hear a loud clicking noise coming from the driver's side footwell, which probably means it's a relay clicking. I have not tried replacing the relay because front windows work fine and from what I read all power windows use the same relay (but then again there is not a lot of info about it and I might be wrong). Also, I suspect that the main power window switch could be bad and maybe it's not letting power through to the other switches, because I was told by some volvo fans that if the main switch goes the other switches stop working, too, but It's also a question mark for me.

2nd problem is high diesel fuel consumption on the highway.

City and combined consumption seems good, but once I get on the highway and I'm cruising at 130-140km/h the fuel consumption is roughly about 8-9 liters per 100km. It used to be about 7 to 7.5l before.

I took it to a garage and they did some diagnosing. I was told my MAF and fuel pressure sensor parameters are not within their boundaries and both of those got replaced. For a while I thought it got better, but after driving some more I noticed that I still don't get the same numbers as before.

It is getting colder outside, but I've had this car for about 2 years and it wasn't affecting it this much anytime before.

It is a euro 3 diesel and all it's eco systems are in place. No egr delete, calatytic converter is still there and seems to function fine (no rotten egg smell that would indicate it being clogged), the power is just as it was. Also I used an egr cleaner spray but nothing changed. Engine is running the same as before and computer is not showing anything else.

Thanks for any help I can get.

[DrDan]

Welcome to the forum. I would suggest to open two threads for the two unrelated problems. I will try to address both here anyway.

Power windows: Try to obtain a wiring diagram online, try to understand and then fault trace the circuit. That's of course very generic but you can identify potential points of failure only when you know how the system works.

Fuel consumption: Possibly faulty thermostat. If stuck open (designed to fail this way) engine warms up more slowly. The more cold air flows at the radiator (highway vs city) the cooler it will run, requiring injection of more fuel.

[precopster]

There is a rear body controller behind a LHS panel in the cargo bay that controls rear window operation. Have you checked fuses on this controller? The controllers can go bad and just take out a single function. On our XC90 the rear controller took out the rear hatch unlock pulse, but the lock pulse worked fine.

[yagger]

First at all check power on both sides of fuse 37.

[yagger]

About your 2-nd problem not easy to say something, need to see your car. Better to come to some professionals.

[rocknotdead1994]

Hello everyone, thanks for the answers.

The thermostat was changed in spring, but I do not think it would affect highway driving that much. The engine temp is normal. Yesterday I cleaned the turbo solenoid, maybe that'll help but it wasn't very clogged. The turbo itself was manually inspected a few months ago and it had little play but my mechanic told me it's fine for the mileage (~400k km). The intercooler and all the hoses are also in good nick. I do not want to take it into shops because they usually start throwing parts at it and I'm tired of that. The dealership is even worse with an older car. Nobody takes the time to actually look into it properly, they just assume parts are failing because they are old (of course there is some truth to that but I replaced many a part on this car just because it was presumed to be the culprit of something that it wasn't).

As for the windows - all fuses that relate to windows are checked and replaced with new ones just to be sure. Still nothing. I do not want to touch wiring. If it's a wiring issue I'll just leave it alone. I don't use the rear windows much anyway. Main thing I was asking: is it possible that it might be the main windows switch problem, because I can get a known good used unit for cheap, but maybe I shouldn't even think about it.

[yagger]

You checked fuses, but I ask to check POWER on that fuse. This is a bit different thing.

[rocknotdead1994]

You checked fuses, but I ask to check POWER on that fuse. This is a bit different thing.

Thank you. I will try that once I get around to it.

I don't think my car has a window fuse in the rear. Nonetheless i checked all rear fuses and all of them are fine.