Heater , blend motors and all things frustrating

[Wallyb]

After chasing my tail trying to sort out my non existant heating.. no fun when you travel Canberra during the week and back to Sydney for weekends.

It seems that I have multiple issues that have confused the signs.

Q1. I exposed as much as I could practically trying to reach the blend motors - testing suggested they may have been an issue. Stopped short of removing the ducts that go to the back seats. Such bad placement. Anyway.. has anyone permanantly removed the ducts? I am not that fused about ducting air to the back seats and so happy to remove them and provide easier future access.

Any thoughts?


While pouring over RAVE to sort things out tonight I just noticed tonight that the previous owner/mechanic has reversed the inlet/outlet pipe to the heater core. grrr.. Solution: I will swap the hoses in the engine bay for now.

Q2 Anyone know what the servo valve looks like internally? Is it just a butterfly valve? I am going to assume that the reversed water flow did nothing but further confuse the HEVAC.

The next problem was the heater core sensor intermittently worked and is mostly in open circuit mode. I am going to experiment with a couple of after market thermistors and see how I go ($1.35 from Jaycar vs $40 from the dealer)

Q3 Does anyone know what the electrical specs are for the original? As best I can work out at the moment 10k @20C apears right. So will kick it of with something close to that.

Thanks

Wally

[wayneg]

The duct going to the rear can be cut and re-attached with duct tape. I Have removed the right hand temp blend motor once before by bending it but next time the Duct is getting the chop. I have a wire saw waiting for the day.
I will be posting a DIY how to very soon on how to renew the potentiometer within the blend motor and where to get the part for $2. I Just need a few hours to do the job.

[p38arover]

On a warm day the duct comes off easily. I have never cut any of my ducts. They are quite flexible.



Q2 Anyone know what the servo valve looks like internally? Is it just a butterfly valve? I am going to assume that the reversed water flow did nothing but further confuse the HEVAC.

What servo valve? There isn't one. The water flow is not controlled through the heater core.

[Wallyb]

What servo valve? There isn't one. The water flow is not controlled through the heater core.


Water flow through the heater core is always on?

[p38arover]

Water flow through the heater core is always on?

Yes.

Cabin air temp is controlled by blending cold air and warm air from the heater. Do you have any control of air temp on the other side of the car? Usually it's only one side or the other that has a blend flap servo fail. I've written some info up here: http://www.rangerovers.net/repairdetails/blendmotor.html

[Wallyb]

cool!

Thanks Ron, something I had misunderstood.

So at least the plumbing on the heater core should makes no difference. I can leave it as is.

I will resolve the temperature sensor issue tomorrow and progress from there.