I know you have working pto but is the switch for a flange drive pto on the gearbox that’s not in use ?
dont think so
its on there for a reason and it works but cant fathom out what its purpose is and can only think that a handbook or
volvo fl expert can explain what it’s purpose is
lucemm:
So much for Volvo (swindon)area manager saying switch is defiantly not a volvo switch!!!
You can, or could, buy a Volvo switch that was unmarked and the body builders or companies that supply aftermarket equipment could put their own pictograms on it. That’s definitely a Volvo switch but it doesn’t mean the symbol on it is Volvo and therefore it might not be shown in the handbook if you manage to track one down.
Does it have air suspension, is it a way of increasing the weight on the drive axle temporarily to give more traction ?
No air suspension
and dosnt explain the tankers on e bay with the switches
i would’nt mind betting it came from the factory as it is
the noise it makes and the loading of the engine all seems too much part of the vehicle and not something that has been added to assist an attachment that has been built on the chassis
my mechanic is coming to pre mot it next week so he may be able to assist
lucemm:
very impressed with your computor skills getting a photo brought up and circling it is way beyond my skills
But does that switch in the red circle have the same pictogram as the one we are trying to figure out on your wagon?
yes thats right
same switch same place
its a Volvo night heater switch 
but it may have been added to operate something entirely different by a previous owner
DAFMAD:
0This it ?
is it the switch above the red circle? that’s a night heater switch
No its the switch that is circled in red next to engine brake on bottom row
Are you sure your truck isn’t amphibious ? 
Looks like a switch to engage the propellor 
green456:
DAFMAD:
0This it ?
is it the switch above the red circle? that’s a night heater switch
Heated mirror switch not night heater.
Don’t know what the switch does the op is on about!!!
theres loads of FL6 with theses switches
Someone must no what its purpose is
Looks like a blower or external pto drive switch i reckon.
tango boy:
green456:
DAFMAD:
0This it ?
is it the switch above the red circle? that’s a night heater switch
Heated mirror switch not night heater.
Don’t know what the switch does the op is on about!!!
well its the night heater switch on mine
the heater mirror switch is not even on the dash, its on drivers door
green456:
tango boy:
green456:
DAFMAD:
0This it ?
is it the switch above the red circle? that’s a night heater switch
Heated mirror switch not night heater.
Don’t know what the switch does the op is on about!!!well its the night heater switch on mine
the heater mirror switch is not even on the dash, its on drivers door
Dunno then, the picture on the switch looks like a mirror that’s all.
your looking at the wrong switch mate
its the one NEXT TO THE ENGINE BRAKE with like four wheels and a arrow going forward
there is a picture of it on this posting with a red circle around it
lucemm:
your looking at the wrong switch mate
its the one NEXT TO THE ENGINE BRAKE with like four wheels and a arrow going forward
there is a picture of it on this posting with a red circle around it
Yes i know which switch you are on about with the red circle round it!
The switch above it looks to me like a heated mirror switch, it looks like a mirror on the switch!!
correct thats exactly what it is and it works on my wagon
The vehicle is a 4x2, yet the dash features an inter-axle diff lock switch, which is obviously not connected to anything, which would seem to indicate that there are also possibly other redundant switches fitted. This is purely guesswork, but the pictogram suggests to me that this might be the symbol used for a vehicle fitted with a retarder (rather than an exhaust brake). The fact that something happens when the switch is operated might only be a solenoid clicking, but which has no load connected for it to switch on. It is quite common for an electrical system to be installed on a vehicle complete bar the final item.