Heater Failure

[goodfella]

Hello,

After experiencing no heater fan in the cockpit on number 1 and 2 setting for over 2 years now I bit the bullit and purchased a new heater control unit off ebay to counter the problem. However, after fitting I still have no number 1 or 2 setting???? Number 3 is fine and blows hot air as it did before but I thought the control unit would be to blame for this....any ideas guys?

Both control units cant have the same fault....the odds of this would be crazy? Or am I missing something?

Thanks.

[jon_st205]

It's the resistor pack, very common fault. AFAIK it's bolted next to the fan blower (ie. difficult to get to), not inside the control unit itself. Do a seach and no doubt you'll find more info.

[jimi]

It's a bit awkward to get to. You have to remove the liner for the glovebox, under that you will see the plastic ducting of the heater, the resistor pack is a black unit screwed into the duct looks like this



The one on the left is from a 1a and the one on the right is from a 1b, both interchangeable, but the 1b one is a better unit.
If you remove you are usually able to see if all the wire coils are intact, you can check it with a multi meter on resistance.
resistor pack values between terminals
1-3 = 2.14 ohms (approx)
1-4 = 1.23 ohms (approx)
2-4 = 0.45 ohms (approx)
Terminal numbers are looking at the resistor pack socket
top left = 1
top right = 2
bottom left = 3
bottom right = 4
They are not usually repairable, best bet is to get a replacement unit, the 1b one is much more reliable.



resistor pack is 87138 on the above diagram

[goodfella]

Brilliant, thanks alot guys!!!

[oukie]

I think I have one of those spare, in really good condition, I will PM you.