Other 70 Problem: Main beam cutting out

[earlyriser]

V70 SE Auto Estate 2002 It is my wife's car we bought it 10 days ago its done 90,000 miles , it has 8 service stamps and we are pleased with it, there have been one or two niggles but the main problem we have is the main beam. Yes the lights are on using the switch, they work fine until the car has warmed up may be 6 miles on main roads, all of a sudden they are on dip you can flash full beam but it wont stay on.
I have had a look today and found that there is a relay behind the dash just above the accelerator, it clicks when the stalk is pulled back, I took it out, then tried the lights they flash but don't stay on main beam with it out (same as the problem)
I manged to prize of the plastic cover it all looked good inside so I have given it a good spray with electric contact cleaner left it for half an hour then blown it off with a airline. I have put it back in and is still working ! although now comes the test as my wife has gone out in the car for the evening .
Does any one know if I am going going up the right track? Can relays behave in this manner?

[Yooj]

There are a couple of things... firstly, you need the light switch in the vertical position to achieve full beam. If it is in the horizontal position, you can only achieve full beam by holding back the stalk.

Secondly, it could be a sign of a DIM fault, as I sometimes get this where I am driving with full beam, and then it just reverts back to dipped beam, and then usually followed by the usual DIM spazzing out and resetting itself.

Yooj

[earlyriser]

Thanks Yooj, the dip side of things seem ok
The fault is still there after last nights trip.
I am going to try and test the relay next and see if it is constant, 12v running through it and see if the output is constant?
Can any body recommend were I could purchase a replacement or suggest other ideas?

[Marmitespreader]

Volvo Dealer
A previous owner may have done some poor lighting mods, you do have standard wattage bulbs fitted-yes, & not silly 100 watters?
Have you checked the shunt in the same fusebox?

http://www.volvoforums.org.uk/showth...?t=9910&page=2

[Brendan W]

Sounds like the car is reverting to drl mode. Could it be the selector switch is playing up? Only trouble ever saw with main beam relays is sticking caused by fitting 100W as Marmitespreader has said. The thing had arced and melted so fairly obvious. There should be a second relay in there for the dipped beam and iirc they are the same. If so could swap over to see what happens.
Another possibility is the lighting control module , see post #9 in this thread.
http://www.volvoforums.org.uk/showth...elector+switch

[earlyriser]

Thanks guys, I called my local Volvo garage today and ordered a replacement relay (8651661) for £12.12 pick it up tomorrow.
I will check the bulb wattage and the shunt before I replace the relay.
Watch this space!

[earlyriser]

I have checked the bulbs (60W) and the shunt which appears to be ok. Have now fitted the new relay which has not made any difference.
As I dont normally drive the car I got chance to have a play tonight, The lights went on to dip once, not for long though, what I found was that the whole area around the light switch failed too ie front and rear fogs, dash fader and headlamp leveler. It must either be the light switch or whatever sends the power to the switch, I was unable to test it so not sure, but I did manage to strip down the switch, I couldn't see anything obvious that could be causing the fault.
Where would I find the light switch module, and what is ETM,DIM,CIM ?

[Brendan W]

The headlight level and dash dimmer control unit. Never removed one but it should pull out.
ETM electronic throttle module
DIM driver information module - the clocks
CEM central electronic module