Great link on repairing duo valves / temp controllers

[vijilants]

http://v12uberalles.com/Rear_AC_System.htm

 

[television]

Thank that is good.

I have a problem in that I have 30-40 good links with photo's what do I do with them

 

[vijilants]

Thank that is good.

I have a problem in that I have 30-40 good links with photo's what do I do with them

You got any good ones on checking the electrics to the duo valves ? I could do with some listing voltages at the pins.

Many Thanks

 

[television]

Sorry do not have that one but I may have that info later in the day when I turn on number 2

 

[vijilants]

Thanks Malcolm,

It would be of great help re a problem I'm trying to sort out. - PM me if you like with the info

 

[tromppost]

What a good write up. The spark plug one is also good.

 

[television]

What a good write up. The spark plug one is also good.

I have 80 super ones and I was hoping the mods might have some idea where to put them

 

[Dieselman]

You got any good ones on checking the electrics to the duo valves ? I could do with some listing voltages at the pins.

Many Thanks

12v variable dwell cycled.

 

[television]

On the control module when both temp selectors in the red,

11 to 14 volt

When set to blue
1volt

 

[vijilants]

I was under the impression that when the power connector is disconnected from the duo valve, this lets the water through. But when power is applied this stops the water from coming through.

Is this correct ?

 

[television]

I was under the impression that when the power connector is disconnected from the duo valve, this lets the water through. But when power is applied this stops the water from coming through.

Is this correct ?

hard one, but you can measure the voltage in the 2 modes or from pins 19-1 on the control box

 

[Dieselman]

The water flows when the solenoid is de-energised, they normally fail in the hot position.

 

[television]

The water flows when the solenoid is de-energised, they normally fail in the hot position.

That would fit if either the control unit or valve failed

 

[vijilants]

OK....i havn't fully checked mine out but this is the problem:

On fully cold, the pipes (both of them) coming out of the duo valve is cold.

On full hot, the pipes are hot, so I get heating.

The problem is the in between settings do not appear to be working. Anything below full hot, the water goes cold.

Hence my reason for the voltages to the duo valve.....how are the valves controlled in the intermediate range ?

 

[television]

OK....i havn't fully checked mine out but this is the problem:

On fully cold, the pipes (both of them) coming out of the duo valve is cold.

On full hot, the pipes are hot, so I get heating.

The problem is the in between settings do not appear to be working. Anything below full hot, the water goes cold.

Hence my reason for the voltages to the duo valve.....how are the valves controlled in the intermediate range ?

I believe that they are pulsed, so not possible to measure with out a scope

 

[Dieselman]

They are pulsed but it's about a 2 second interval so should be able to be metered with a DMM.

 

[vijilants]

AVO MK8 would have done the trick but I don't have one any more. I only have a Fluke 75....will give it a go with this.

Do you know where the unit is located which send out the pulses ?

 

[television]

They are pulsed but it's about a 2 second interval so should be able to be metered with a DMM.

not easy with a DVM because of the gate time, you would see it on an analogue meter

 

[Dieselman]

not easy with a DVM because of the gate time, you would see it on an analogue meter

Agreed, but he only needs to see a change of state not an actual value as the value is either 12v or 0v.

Best to not use an auto ranging meter though.

 

[Bazzle]

Just put your hand on the units, you can feel the pulses and the dwell time. Meter not needed IMO

Bazzle