t25 Heater confusion

[blue67]

The heater fan switch didnt appear to be doing anything so a new replacement was acuired and duely fitted, fan still doesnt work but when the new switch is turned to position 3 the fuse blows!

Any ideas where to look for further problems please?

[bigherb]

Sounds like the heater motor has siezed.

[Aidan]

you need to test the motor if it's seized and short circuited that'll blow the fuse, you also need to check the wiring for a short, vehicle electrician with a copy of the wiring diagram would be best if you aren't confident of continuity testing.

[blue67]

you need to test the motor if it's seized and short circuited that'll blow the fuse, you also need to check the wiring for a short, vehicle electrician with a copy of the wiring diagram would be best if you aren't confident of continuity testing.

Checked the wiring to where it goes into the heater box and that is fine. I am pretty confident, and kinda thought it may have been the motor or resistor. How would be the best way to test the motor? is it common for the motor to fail?

[CovKid]

Er yes it is. Worse, when the fuse blows it also takes out the windscreen wipers circuit as I discovered one wet night on the M1.

You need to get dash out, pull blower box out, give motor a spray with wD40 - this often frees it off. Days work but dooable. Its in the WIKI. Few of us have been where you are.

Do it before cold weather comes - you'll need that blower then.