Transitmania 6 @ Billing Aquadrome Aug 22nd to 24th 2014


heater fan motor blowing fuse

Transit Mk3, 4 & 5(smiley front) Forum. All Transits 1986 - 2000

heater fan motor blowing fuse

Postby fridge doctor » Wed Sep 21, 2011 8:25 pm

Hi,

The 30A fuse blow when I turn the fan on (any speed). The rheostat speed control is fairly new and not shorting on to the chassis anywhere.

My local garage (Non Ford) just want to rip out the dash thinking it's the fan motor at fault... I'm not so sure, anybody got some other ideas please?
User avatar
fridge doctor
Transit Aficionado
Transit Aficionado
 
Posts: 183
Joined: Thu Aug 23, 2007 9:40 pm
Location: Cyprus

Re: heater fan motor blowing fuse

Postby bamber1 » Thu Sep 22, 2011 9:32 pm

Got the same thing myself, found the prob to be a worn and dodgy 3 way connector on the heater resistors behind the headlamp (presumably bad connections causing high load on fuse?) got a new one from Halfords (£3.29) and after cutting off the old one I connected the new one one with a choc block connector and wrapped it in PVC tape.

As the old fuse box melted due to high speed no 3 setting being left on too long (common prob apparently) I replaced it which was a b*stard of a job, unfortunately my son took the van down to France and I forgot to tell him not to use 3 setting for too long with the result that melting has already started again so to cure things once and for all I am installing a relay to supply heater direct from a fused supply direct from battery, this will only supply fan when on no 3 setting leaving setting 1 and 2 running as normal through the fusebox.
bamber1
Transit Addict
Transit Addict
 
Posts: 56
Joined: Thu Mar 17, 2011 8:19 pm

Re: heater fan motor blowing fuse

Postby fridge doctor » Fri Sep 23, 2011 4:43 pm

Hi bamber1,
I just took a look at the triple connector and it looks fine. Supplying the fan speed 3 direct sounds like a good idea though... but how do you know which wire is the right one? If I pull the connector off, or even cut the wiring to it, are there any tests I can do... I thought the resistor had to be in circuit, or is that just for the lower speeds?
Thanks for your help.
User avatar
fridge doctor
Transit Aficionado
Transit Aficionado
 
Posts: 183
Joined: Thu Aug 23, 2007 9:40 pm
Location: Cyprus

Re: heater fan motor blowing fuse

Postby bamber1 » Fri Sep 23, 2011 6:06 pm

fridge doctor wrote:Hi bamber1,
I just took a look at the triple connector and it looks fine. Supplying the fan speed 3 direct sounds like a good idea though... but how do you know which wire is the right one? If I pull the connector off, or even cut the wiring to it, are there any tests I can do... I thought the resistor had to be in circuit, or is that just for the lower speeds?
Thanks for your help.


Bit of an update and change of plan.

Today after running a direct fused feed to the heater speed switch that fuse kept blowing, turned out to be the resistors shorting out on the metal cage, fixed that and it now runs fine so I have decided to keep it like that, the only prob is the fan runs with ignition off (due to direct feed from battery) so the next thing is to run the feed through an ign powered relay.

On my van I cut the main feed into the rear of the speed switch (violet with black tracer- comes from the fusebox) and connected direct feed onto that wire into the switch with a choc bloc. The cut end that goes back to the fusebox needs blanking off with tape or something.
So all speeds are now powered direct from the battery.
If you look at a wiring diagram you will see that full speed is diverted past the resistors which only give lower speeds.

As the weak link seems to be the main fusebox being overloaded on full fan speed and melting I'm hoping the speed switch will be ok handling full speed amperage, will have to wait and see.
bamber1
Transit Addict
Transit Addict
 
Posts: 56
Joined: Thu Mar 17, 2011 8:19 pm


Return to Mk 3, 4 & 5 - Second Generation Transits



Who is online

Users browsing this forum: AndyG