heater control haywire

[red griff 500]

Anybody else's hold/cold stepper motor driven valve going round and round and......

More to the point; anybody got any suggestions as to why it's doing it?

[griffter]

No, but I do like the name of your post. My loom's made largely of haywire too.

[VSP90]

Search for "Too much hot air" Its a thread I started in July 05
There could be some info that may help you !

[mongoose]

If it just spins round and round,then its very likely that the 'pot' on top of the motor shaft has failed.These cost pennies to just replace on their own(simple soldering job),as opposed to £60ish for the complete unit.The problem is that on the earlier cars,the pot is a 15mm diameter type,which is getting difficult to find,if you have the later type,they are 10mm diameter,and very easy to get hold of.

[JoolzB]

VSP90 said:

Search for "Too much hot air" Its a thread I started in July 05 There could be some info that may help you !

Yeah loadsa info on this, I had months of fun with mine and there were a few threads posted. The problem with mine turned out to be a prob with the environment control (there's 2 circuit boards), just a bit of solder fallen off but it took a fellow PH'er to spot that. I'd check some of the other easier options before you start tinkering with these tho.

[red griff 500]

Thanks for the replies lads (and lasses?)! I've had a look at the other threads and there's some good info there.

anyone got any sugestions as to how to diagnose which part of the system isn't working correctly (e.g. how to determine whether the "pots" are functioning correctly?).

Out of interest, where do you get the pots from? I'll measure mine to see whether they are 10 or 15mm.

>> Edited by red griff 500 on Wednesday 7th December 22:44

[IPAddis]

red griff 500 said:

Thanks for the replies lads (and lasses?)! I've had a look at the other threads and there's some good info there. anyone got any sugestions as to how to diagnose which part of the system isn't working correctly (e.g. how to determine whether the "pots" are functioning correctly?). Out of interest, where do you get the pots from? I'll measure mine to see whether they are 10 or 15mm. >> Edited by red griff 500 on Wednesday 7th December 22:44

I removed the pot from the recirc valve (which worked) and put it onto the heater valve. This made no difference so it appears that the problem is elsewhere. I jiggled around the heater ECU a while ago and the heater is better but not perfect. The direction valve is now playing up occasionally as well.

Only happens when it's cold or I haven't driven the car for a while. I think it's a TVR sulking thing.

Ian A.

[Toffer]

Never mind...Toffer as unhelpful as always would say.."They all do that sir!"

[mongoose]

IPAddis said:

I removed the pot from the recirc valve (which worked) and put it onto the heater valve. This made no difference so it appears that the problem is elsewhere. I jiggled around the heater ECU a while ago and the heater is better but not perfect. The direction valve is now playing up occasionally as well. Only happens when it's cold or I haven't driven the car for a while. I think it's a TVR sulking thing. Ian A.

There are three white connectors along the side of the heater control unit,each of them has 5 connections.The sloping pin type connector held in these white plugs can make a bad,or no contact,as they easily bend down,and connection relies on only one face mating with the pin that comes out of the control unit.I had this problem when my re-circ valve wouldn't work.Each terminal can be removed from the housing by pushing against it with a small screwdriver on its locking tab whilst sliding it outwards,then you can bend up the terminal itself and push it back in the connector.It will now make better contact with the pin in the heater control unit,and if this was your problem,it should now work!

[red griff 500]

Just to let you know, the problem was with the pot attached to the motor. I just fiddled with it and it started working correctly - must've been a loose connection or a wire filament shorting two terminals I guess. Ah well, that probably means it'll happen again one day!

[IPAddis]

mongoose said:

IPAddis said: I removed the pot from the recirc valve (which worked) and put it onto the heater valve. This made no difference so it appears that the problem is elsewhere. I jiggled around the heater ECU a while ago and the heater is better but not perfect. The direction valve is now playing up occasionally as well. Only happens when it's cold or I haven't driven the car for a while. I think it's a TVR sulking thing. Ian A. There are three white connectors along the side of the heater control unit,each of them has 5 connections.The sloping pin type connector held in these white plugs can make a bad,or no contact,as they easily bend down,and connection relies on only one face mating with the pin that comes out of the control unit.I had this problem when my re-circ valve wouldn't work.Each terminal can be removed from the housing by pushing against it with a small screwdriver on its locking tab whilst sliding it outwards,then you can bend up the terminal itself and push it back in the connector.It will now make better contact with the pin in the heater control unit,and if this was your problem,it should now work!

Hmm, interesting. I might have a look at that, all I can remember from the ECU was the ribbon cable and a feck-off big heatsink. I'll try playing with the white connectors.

Cheers,

Ian A.

[red griff 500]

i'M PUZZLED BY WHAT YOU GUYS ARE CALLING THE HEATER ECU. IS THIS THE PCB MOUNTED UNDER THE TEMP CONTROL PANEL? IF IS IS, THEN I HAVE A RIBBON CABLE WHICH PLUGS INTO THIS WHICH THEN DISAPPEARS UNDER THE DASH. I LOOKED FOR THESE WHITE CONNECTORS ABOVE THE GLOVE COMPARTMENT (DOES ANYBODY PUT THEIR GLOVES IN THESE THINGS NOWADAYS?) WHERE THE CABLES FROM THE MOTORISED VALVES DISAPPEAR BEHIND THE DASH. I GUESS THE CONNECTORS ARE WHAT CONNECTS THE CABLES TO THE RIBBON CABLE. IS THIS CORRECT? I COULDN'T FIND THEM.

[JoolzB]

red griff 500 said:

i'M PUZZLED BY WHAT YOU GUYS ARE CALLING THE HEATER ECU. IS THIS THE PCB MOUNTED UNDER THE TEMP CONTROL PANEL? IF IS IS, THEN I HAVE A RIBBON CABLE WHICH PLUGS INTO THIS WHICH THEN DISAPPEARS UNDER THE DASH. I LOOKED FOR THESE WHITE CONNECTORS ABOVE THE GLOVE COMPARTMENT (DOES ANYBODY PUT THEIR GLOVES IN THESE THINGS NOWADAYS?) WHERE THE CABLES FROM THE MOTORISED VALVES DISAPPEAR BEHIND THE DASH. I GUESS THE CONNECTORS ARE WHAT CONNECTS THE CABLES TO THE RIBBON CABLE. IS THIS CORRECT? I COULDN'T FIND THEM.

There's s couple of PCBs, the ribbon cable that you're talking about goes from the knobs "TVR Environment Control" to another PCB that was under the radio on mine and is a black plastic case. This has several connectors that go off to the various motors.

[mongoose]

JoolzB said:

There's s couple of PCBs, the ribbon cable that you're talking about goes from the knobs "TVR Environment Control" to another PCB that was under the radio on mine and is a black plastic case. This has several connectors that go off to the various motors.

This is what i'm referring to.More commonly known as the heater control unit/ecu

[red griff 500]

Ahhh, it's becoming clear now!

[barreti]

I've read about this heater ecu in other threads. Do all Griffiths have it or is it just a 500 thing? I can't find anything about it in the bible.

[griffter]

barreti said:

I've read about this heater ecu in other threads. Do all Griffiths have it or is it just a 500 thing? I can't find anything about it in the bible.

Not on my '92 - just Cavalier window switches to control the heater valve motors and microswtiches on the heater valves to stop the motor turning too far.

[barreti]

griffter said:

barreti said: I've read about this heater ecu in other threads. Do all Griffiths have it or is it just a 500 thing? I can't find anything about it in the bible. Not on my '92 - just Cavalier window switches to control the heater valve motors and microswtiches on the heater valves to stop the motor turning too far.

Thanks Griffter. Thank god for that, I thought I was missing something (apart from heat that is!)