Join Date: Mar 2002
Car: Mk2 ZS 160, 200vi(RIP) & Freelander XEDi
Pin 86 of the HRW relay should not have 12 volts on it, it's a ground for the relay coil.
Pin 85 should only have 12 volts present when the MFU switches the relay on.
The HRW switch is a momentary type, it pulses the MFU input to ground which toggles the relay on and off at each press of the switch, a timer within the MFU switches the relay off after 15 minutes of operation.
This switch input also means that the HRW cannot be left switched on accidentally.
Fuse M also provides the MFU with it's 12 volt operating voltage.