Q One of my customers asked me to look at his 59-plate Citroën C5 because his heater blower has stopped working 90% of the time. I can’t find a Haynes manual for this particular year, only for the preceding years. My first thought – at the time, the blower didn’t work at all – was the resistor pack. After hunting around, I believe I located it high up on the right-hand side of the passenger footwell. I was unable to detach the wiring connection as you can’t see it properly, but it seems that you need to disconnect this in order to be able to turn the resistor pack to extract it. I tried taking out the glovebox for easier access, but even after undoing every screw it refuses to budge!
After this, the blower started firing up, but soon stopped again. You operate the air-conditioning and blower via buttons rather than a dial and it seems to be an integrated environmental system rather than the old-fashioned way of doing things. Mark Boundy
A The problem may well be the rheostat, but it could also be that the motor is suffering from worn brushes or corroded bearings. As the motor does operate occasionally, it may be possible to check this by giving the visible end of the motor a sharp tap while the engine is running and the motor is turned on. If this prompts the motor to start rotating, it is likely to be the motor and not the rheostat at fault. It’s also possible that the problem is due to a fusebox connection, so a quick check of the fuses to ensure they are in good condition would be worthwhile.
If the rheostat is to blame then the glovebox will need to be removed to get access. The glovebox should be held in place by 10 screws – three along the base, five around the inner lip of the glovebox housing (three across the top and one each side) and two screws towards the back. Before the glovebox is removed you will need to disconnect the glovebox light and the air-conditioning input. You will also need to detach the passenger airbag switch – to do this the battery should be disconnected before you start.
With the glovebox out, you should be able to access the rheostat and, by turning it a quarter-of-a-turn, it should lift out. It is a fiddly job and, having been sitting in the top of the heater for a while, it may be tight to turn.
One other point to check is the condition of the battery and charging system. The complex economy mode system in the C5 will prevent the blower from working if the battery voltage is too low.
The electronic Citroën rheostat unit.