Dodgy rad fan and coolant change advice wanted..

Post by **Hacksawbob** » 29 Apr 2007, 22:35

there is a test procedure in haynes basically short out the eah two in turn of the socket that plugs in at the front right hand side of the radiator.

switch, someones added it.

wiki on coolant

Post by **Hacksawbob** » 30 Apr 2007, 18:05

if the fuse is blowing you maybe have a short to earth somewhere maybe the fan is drawing too much current?

Post by **irish.david** » 30 Apr 2007, 18:32

The 2 speed radiator fan wiring goes as follows.

12v supply to the thermoswitch on the rad comes from the "always live" line (30 in the wiring diags), through the 16A fuse (fuse 7 on the early fuse box) and to the switch connector.

When the rad reaches it's lower temp the thermoswitch connects the 12v to directly to the fan motor on the slow speed portion of the winding. The wire to the slow speed on the fan is black/red and, from memory, is the in the centre of the connector.

When the rad gets to its high temp the thermoswitch connects 12v with the coil of a relay hidden behind the dash. This relay directly connects the 12v line to the high speed winding portion of the rad fan and then the fan really goes for it. The high speed wire is red/blue. I guess the reason for this relay is the thermoswitch can't deal with the current required to run the fan at full speed.

If the fan keeps blowing fuses you should check the resistance of the fan windings. On the rad thermoswitch connector check the resistance between the black/red wire and ground and the red/blue wire and ground. There should be a small, but measurable resistance on both.

Dave

Post by **irish.david** » 30 Apr 2007, 20:30

Hmmmm, i've checked the wiring diags in the Bentley Workshop manual for the early fuse box and it definitely has the rad fan fuse rated at 16A. However, i've just checked the Haynes manual and the same fuse is rated at 8A. Also, somewhat cryptically, both manuals agree on a 30A fuse for the rad fan in the late fuse box......

I think it's time to had this over to someone with more experience in these matters......

Dave

Post by **tonytech** » 01 May 2007, 21:27

My 2.1 needs the temp gauge to be 3/4 before the fan kicks in.

T

Post by **dave friday** » 01 May 2007, 22:48

hi,my van's fan seems to be a bit independant of the temp guage reading, e.g. after 20 minutes driving up hill in third and top gear[mixed] the fan comes on after the engine is off for two minutes[about].
barry