RHD Supra Heater issues

[Sam]

I live in Saskatchewan, Canada. I've owned this 1991 Supra Twin Turbo R for over a year now and the heater has never worked (The AC works however, just the heater slider never worked). When it got cold, I simply didn't drive the car and ended up parking it in the garage for the winter. However this year I cannot, my father will not lend me his spare vehicle this year as he needs it.

So now I need the heater to work. Now I've tried just about everything to figure out what wrong with this thing. I've determined it was the unit itself. All the wiring coming into the unit all worked.

I know it's simply the unit because at random times the heat will magically start working and then randomly stop again. There must be some kind of loose connection inside the unit. I opened the unit and cleaned it and put it back together with everything in order. I could not find any loose connections.

Here is the heater.

For some reason I found the heater worked in this position! Why when it was angled it would work? And no it's not because the wiring in the back is being manipulated. I manipulated the crap out the wires in the back hoping for a faulty one. So why would it work while being tilted?

The wires and the sockets are healthy I determined.

Also I heard that the USDM model of heater unit will not work because of the sockets. Can anyone confirm?

Here is the back of the heater unit

Another question, this one is for the Australian members. Do the heater units in your Australian Supras match the JDM units? If so, I have a connection in Australia, and I could order one from there if Toyota still has them laying around over there.

Has anyone had this problem with their heater units? Any comments or suggestions is greatly appreciated.

 

[Whosoever]

If you think you need to replace it, I have both the climate control & heater control module in the engine bay if you need it...

 

[martin p]

on the back of the Heater unit remove the screws holding the circuit board in(small board with white plug on) and re solder the pins on the multi plug, see if that works, it a common fault on both jdm and Euro spec cars! if not i can source you a working one from the UK, (secondhand)

This plug,

Also the water valve on the bulkhead also stops working, that can be held or zip tied up to see if heat comes out of the vent, this valve stops hot water entering that heater matrix hence lack of hot air.

 

[IJ.]

Dead or dying amplifier box, I had this condition when I got my car.

 

[Sam]

on the back of the Heater unit remove the screws holding the circuit board in(small board with white plug on) and re solder the pins on the multi plug, see if that works, it a common fault on both jdm and Euro spec cars! if not i can source you a working one from the UK, (secondhand)

I'll try resoldering the pins back in place. However, if that does not work I may PM you about sourcing me one from the UK. That would be very nice indeed.

Dead or dying amplifier box, I had this condition when I got my car.

I'm sorry, I'm not the most technically knowledgeable person. What is this amplifier box you speak of? Is it inside the heater unit or somewhere else in the vehicle?

 

[10secdream]

I have the exact opposite troubles as you do as my heater will only blow hot air.... Maybe I just take apart my climate control and solder the pins as well.

 

[IJ.]

Sam: Up under the glovebox, you need to remove the ECU to access it and it's clipped to the Dash bar.

It's a small plastic box and it amplifies the signal from the climate control to something the Heater controls can actually use to set the blend door position.

If you either bypass or cabletie the Heater BSV open and it's still cold this will be the cause.

 

[garagefujimoto]

Yeah, the JDM climate box gets intermittent slider contact, just grab another one.
I can mail you one to SK if you'd like

 

[Sam]

on the back of the Heater unit remove the screws holding the circuit board in(small board with white plug on) and re solder the pins on the multi plug...its a common fault on both jdm and Euro spec cars!...

I resoldered the pins on the muti plug and now my heat works again! Thanks alot Martin and to everyone else who had suggestions.

 

[martin p]

I resoldered the pins on the muti plug and now my heat works again! Thanks alot Martin and to everyone else who had suggestions.

Glad you have got it sorted, this is a very common issue with jdm/euro spec heater control units!!! resoldered mine several times :cry:

 

[BigTree]

kk, so you removed the screws and re soldered like the 16 pins or so?

My JZA70 unit does weird things sometimes, I will have to try this.

 

[martin p]

kk, so you removed the screws and re soldered like the 16 pins or so?

My JZA70 unit does weird things sometimes, I will have to try this.

Yes it as easy as that to do.