Auxilery Water Pump not kicking in

[VR6Pete 0]

No worries pal, I've not done a thing this weekend after having a discography on Friday.

 

Still stumped though! All fan speeds working.. Bridged the rad sensor and also the black sensor on the stat housing.

 

The only thing I've not been able check is the FCM. But unsure what actually 'tells' the pump to run on it's own after ignition is off.

[crrdslcvr6 10]

The FCM gives the pump power to run after the idnition is off. If the small connection is disconnected from the FCM the pump will stop.

[VR6Pete 0]

I suppose the next thing to check is that the FCM is receiving power when ignition is off? Anyway of checking this?

[RW1 0]

Don't understand. :scratch:

If you can bridge the yellow connection as before and it runs the aux pump & rad fan when the ignition is off, then all that circuit is fine including the FCM. To me it means the thermoswitch unit (was yellow, now black) in the thermostat housing is not working. Test it like a thermostat in hot water and see if its contacts close to make a circuit.

 

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[VR6Pete 0]

Don't understand. :scratch:

If you can bridge the yellow connection as before and it runs the aux pump & rad fan when the ignition is off, then all that circuit is fine including the FCM. To me it means the thermoswitch unit (was yellow, now black) in the thermostat housing is not working. Test it like a thermostat in hot water and see if its contacts close to make a circuit.

 

.

 

I know that sensor is OK, as the fan and aux pump does run together when ignition is off when the car is running hot....

 

its the function where the aux pump runs on it's own on ignition is off that doesnt work...

 

Pete

[lewvw 10]

I have the exact same issue, i have replaced the yellow (black) sender the aux pump and the rad fan switch which leaves me with just the fan control unit. Although some people say late vr's don't run the aux pump unless either ignition on or temp requires it.

[crrdslcvr6 10]

I do know some people who have bypassed the pump but as far as I know all VR6 corrados came with it. I think your FCM may be acting up.

[fla 9]

late vr's don't run the aux pump unless either ignition on or temp requires it.

 

correct

[poll250 0]

Does the Black temp sensor (one of the right of the thermo housing) also control the Aux Water pump? I always thought it only controlled the super high (110 deg) fan speed?

 

Mine has been disconnected for about 3 years eeek.

[VR6Pete 0]

Does the Black temp sensor (one of the right of the thermo housing) also control the Aux Water pump? I always thought it only controlled the super high (110 deg) fan speed?

 

Mine has been disconnected for about 3 years eeek.

 

yep - it controls the top speed - you can confirm this by bridging the connections :)

 

---------- Post added at 01:24 PM ---------- Previous post was at 01:16 PM ----------

 

correct

 

late vr's don't run the aux pump unless either ignition on or temp requires it.

 

I think this is where the confusion has come from... :) some people saying that there's does run, and others that dont..... My Golf used to run upon ignition off, but I'm not sure if this was an OBD2 thing?

 

I did speak to Vince yesterday who said he had 2 Corrado VR's and they did not run the pump on ignition off, and one had been on the rollers so I imagine was running upto temp.

[crrdslcvr6 10]

OK. According to the bentley manual the middle sensor in the thermostat housing, (yellow) controls fan and electric pump run on. They say to turn ignition on/off disconnect sensor and bridge brown/red and brown wire. Pump and fan should both come on. I changed all my sensors in the housing a few years ago. My pump runs with ignition even when the car is cold. I have to check this out. I may have a problem.

[RW1 0]

My pump runs with ignition even when the car is cold. I have to check this out. I may have a problem.

 

Thats normal for a late VR.

 

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[crrdslcvr6 10]

Thank You. :thumbleft: