On one of our version 2 fh’s the heated mirror switch isn’t working we’ve tried a new switch checked the fuses checked for broken wires but no joy have any of you had this problem and found the cause? We would run a live feed to the switch but don’t know the exact wire to link it to
I’d say it’s probably a broken wire in the door shut area, between the body and the door. Running a live feed should be fine although I don’t know what connector it goes to, you’d need to look at one which was working with a multimeter I would guess?
could be the heating element on the rear of the mirror
scotstrucker:
could be the heating element on the rear of the mirror
I thought that at first, I’ve had a couple needed to be replaced on FH12s, but then I re-read it and assumed he had ascertained that no current was getting past the switch. If he hasn’t done that then I would agree that he should view the element with grave suspicion and do a continuity test on it with a multimeter.
Check the relay, cant remember which number it is, but the Volvo relays are not the best and get extremely hot under the dash.
We change them every 2 year.
There is no power to the switch as the light on it don’t come on I’ve tried a working switch out of mine and that don’t light up either as for a relay I can’t find one for the mirrors either on the dash or in the owners manual the engine has to be running for the heated mirror switch to work but finding out what colour the power wire is for the switch is another struggle as if I knew that then would simply run another live to it
Cheers
Does anyone know what relay it is or what colour the wire is that goes into the switch so I can run a feed to it ?
Cheers
ive got the info on mirror heating problems at work in my tool box , i could give you the info tomorrow evening if thats any use, i seem to remeber its a relay but cant remember which one
Check fuses (main fuse box) F14 / F24 / F39
Relais 7 and 9
The easiest thing to do is swap the relais over (relais 1-4 are different these are the power relais for the fuel injection, starter motor etc.) 5 si for the I-shift the rest you can swap with each other.
If that doesn’t bring a solution, look than in rubber flexible bit between the door and the body, quite often cables get crunched here. we normaly cut it carefull open and put it back together with silicone tape.
Cheers for the replies
relay K1 should be the offending item unless the wires are broken inbetween the door and cab
My usual order to check for most likelihood of fault would be
Fuse
Element on actual mirror glass and also connections to glass for corrosion
Wires
Relay
Switch
Multimeter continuity tester best way to test glass element and switch couple of wires with crocodile clips soldered to 24v bulb is a quick way to test the supply is getting to the mirror glass. If you do this first and it lights up you know immediately it’s the glass element - if you’re not workshop equipped you can always disconnect the wires from the glass and touch to any 24v in cab accessory where polarity’s not an issue.
Most heated mirrors run through a relay that is triggerd by the alternator out put.The mirrors will only work if the alternator is charging.
Suppose the idea is to stop you flattening the battery if you leave them on.