Heater fan does 1,2,3 but not 4

[Paulinwales]

Hi there my front heater fan will function on low=1 , 2, 3 settings but the led on the dial goes off on 4
the rear fan is working fine

anybody got any ideas on this, I have read the heater fan resistor article but does nto really takle high settings not acheived and to my mind high setting should not need any resistance = highest voltage

I have checked all the voltages commng from the cab electrics (that connect to the restist and they all give out voltages )
I can not see any broken connections on the plate side

anyone got any ideas?

rgds Paul

[g8dhe]

Is the Fan working on the Hi setting ? You say the LED goes out but you don't say what happens to the Fan ?
If it is not then it sounds like the thermal fuse on just the 4th setting has blown and will need resoldering.

If it is then that sounds a bit odd .. has anything else happened just before this happened ?

[Northern Bongolow]

is it a manual or digital system ??

[Paulinwales]

hi guys

the fan is manual not digital
on lower settings the fan works fine on highest setting led and fan both switch off

no problems otherwise the rear heater is uneffected
would just be nice as i use it as a paddling wagon and need to heat up fast and get rid of lots of moisture

ps i am guessing the ac unit could be used as some sort of dehumidifier as well yes?

rgds Paul

[Paulinwales]

Is the Fan working on the Hi setting ? You say the LED goes out but you don't say what happens to the Fan ?
If it is not then it sounds like the thermal fuse on just the 4th setting has blown and will need resoldering.

If it is then that sounds a bit odd .. has anything else happened just before this happened ?

where is the thermal fuse on the 4th setting found? and how would i verify this?
just bought the vehicle was like this when i bought it

rgds P

[wonkanoby]

have a loook at faq sheet in members bit

[Paulinwales]

hi wonkanoby, i already read that but relates more to settings 1,2,3 not working but 4 working

rgds p

[wonkanoby]

but im sure it talks about resoldering bits to remake contacts is not the 4th setting similar?

its normally those that go as they put a load and cause heat in regulating it

your case is unusual as the 4th unregulated setting is the one normally left working

[bigdaddycain]

Hi, is the LED you mention the green LED within the aircon button? I think geoff's suggestion is likely, the aircon won't operate without the fans being on. If in position 4 effectively switches off the fan, then the aircon will not operate also.

[Paulinwales]

sorry guys, might have caused confusion there had a closer look and the green phorescent stuff used to ligthup the settings is uneffected it was just the angle i was looking at made it look as if it switched of it's rather dim.

to simlify the settings 1,2,3 work 4 does not
I checked for solder breakages but all look fine
I checked the voltages at all the contacts before the plate joints and all showed 12.03 volts except 1 which showed 0.32V which i guess relates to point 4 any ideas?


if we start with the plates numbered from top left 1 as you look at it this is what my diagnostics told me

diagram below represents connections from inside vehicle that would go to resistor box . i.e. top part of resistor box when you take it off.

o1 o2
o5
o4 o3


2-4 = 12.o3 v (voltage probe touching point 2 & 4 )
2-3 = 12.03 v
2-5 = 0.32 - guessing this represent setting 4
1-2 - 12.02 v

hope i have not confused anyone here


rgds paul

[Northern Bongolow]

i would remove the resister pack,open it up carefully,then you should see that one of the soldered links has come adrift,carefully resolder it and test.