Club 80-90 Forums

Is it possible/ Sensible?

I’m not inclined to remove the whole heater box at present and disconnect the heater matrix.

Is it feasible to open the heater box in situ and replace the motor and resistors?

Or am I opening an extra box of pain for myself.

If not possible, I’ll leave it until next autumn/winter.

Thanks Matt

It's absolutely not possible to do it this way. The blower is in the middle of the heater box and you need to take the box out and split it in half to get at the motor. Tricky enough on a bench. Impossible under the dash.
While you have the box apart it's a false economy not to fit a new foam seal kit, too.

For what it's worth, Disconnecting the heater matrix doesn't usually spill much fluid at all if you release any pressure then refit the cap.

ive replaced a few and left the heater box in place, its fiddly but not to difficult, you still have to undo all the fixings but you can leave the pipework on

Having thought it through, it does only make sense to attend to all whilst the dash is out.

I want to tidy wiring and fit headlight relays etc. so best to take my time and do all in one go next winter.

I should know better at my age than to try and rush a job through

SyncroMatt wrote: ↑04 Mar 2025, 14:35 Having thought it through, it does only make sense to attend to all whilst the dash is out.

I want to tidy wiring and fit headlight relays etc. so best to take my time and do all in one go next winter.

I should know better at my age than to try and rush a job through

It’s a couple of hours for the fan , a day to do all that

I might have got the wrong end of the stick - do you mean removing the dash but leaving the heater box in?

I did mine by removing the dash, Then splitting the heater box in place, This meant not having to un-plumb the matrix, However I don't really see an easier way, It's not like the dash is hard to remove on these.

Getting the dash out is easy but it's all the random previous owners bodges you find under there that take the time to solve, especially if they have fished wires through the dash support struts etc.
Once the dash is out it's nothing of a job to remove the heater box off the bulkhead really. You could even get some of them red plastic clamps to close off the heater hoses, but as it's the highest point of the system, you can do it without losing more than a cupful of coolant. No need to re-bleed it or anything, just take it for a run and top the header tank up.

I just took it out completely and I have never done a dash on a t3 before. did not take me long couple of hours at most. I did do the washer pipework at the same time which added a bit to the day. 

Here is a pic of the heater box split without removing the matrix pipes. You can see the motor and resistor as well as a still piped up matrix, I stuck mine back together with blobs of black silicone as the case snaps back together fairly well and should be easy to strip if I have to do it again.



 

Thanks all for the replies.

To clear up any confusion, my plan was to remove the dash and then open the heater box in place. Then replace the fan and resistors.

I’ve plenty to be doing (mostly house) and MOT due in a months time.

So I think I’ll leave it until after the summer and do it correctly at a less pressured time

Matt