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Stormgrey93

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Discussion starter · #1 ·
I have a 93 Passat VR6.Can't get my aux. waterpump to work.I know it is good because when I apply 12V to it (with jump wire from bat.)it runs.Checked the plug w/Dig. volt meter shows none or very little voltage w/key on&off.Anyone know what or if there is a fuse or relay that runs this?Thanks
 
Re: Is there a relay or fuse that operates the aux. waterpump? (Stormgrey93)

Your radiator fan control unit is what powers it up. You could bypass it and run a relay yourself, although you would want a timer for the run-on period I suppose.
 
Re: Is there a relay or fuse that operates the aux. waterpump? (barrygti)

Quote, originally posted by barrygti »
Your radiator fan control unit is what powers it up. You could bypass it and run a relay yourself, although you would want a timer for the run-on period I suppose.

x2 - may be the theromoswtich in the rad also. Do the fans come on?
This is the piece we're taking about in case you didn't already know: (sits near the coolant bubble on the LF strut tower)
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Discussion starter · #4 ·
Re: Is there a relay or fuse that operates the aux. waterpump? (Scotty_2.0)

Yeah,my fans kick on when the temp gauge gets a little over halfway.The fan control unit looks ok,from what I can tell,it still has the strip that goes across to make the connection.I'll check out what youv'e told me.I may have to put a toggle on it.I was going to try and see if I have any broken wiring down the line.I appreciate the response and will still take any suggestions.
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Re: Is there a relay or fuse that operates the aux. waterpump? (Stormgrey93)

Quote, originally posted by Stormgrey93 »
The fan control unit looks ok,from what I can tell

A bad FCM can look just like a good FCM. Mine did.
 
Discussion starter · #8 ·
Re: Is there a relay or fuse that operates the aux. waterpump? (Stormgrey93)

Thanks everyone.I will check the FCM out again.

Does anyone know or remeber if there was a fuse or relay which one it was or what it may have been linked/joined up with?
 
Re: Is there a relay or fuse that operates the aux. waterpump? (Stormgrey93)

The FCM is actually a combination of multiple fuses, relays and at least one timer. If you look at the image from earlier in the thread, there are multiple fuses integrated into the FCM beneath the clear plastic window to the lower left.
 
Discussion starter · #10 ·
Re: Is there a relay or fuse that operates the aux. waterpump? (Kenji)

Seems like my FCM works.The fan does kick on.Just can't get the Aux.water pump to run.I have a new CTS.I checked my fan just for sh@ts and giggles and it runs when I fused it.I did notice that I have only one speed on my fan when it runs.When I fused it the fan would run High and low.Does the FCM control the fan speeds?Or the switch in the rad?All my fuses check out as well.Man I am getting confused there seems to be so many things that run the fans,lol.
When the Aux. pump runs,does it run as soon as the car is started?Or is it timed out to run once the thermostat opens?Just wondering,cause if I do wire it up I want to make sure that the coolant is flowing through it .Any help is appreciated.
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Re: Is there a relay or fuse that operates the aux. waterpump? (Stormgrey93)

Quote, originally posted by Stormgrey93 »
Seems like my FCM works.The fan does kick on.Just can't get the Aux.water pump to run.I have a new CTS.I checked my fan just for sh@ts and giggles and it runs when I fused it.I did notice that I have only one speed on my fan when it runs.When I fused it the fan would run High and low.Does the FCM control the fan speeds?Or the switch in the rad?

The speed is controlled by the FCM, but is also triggered by coolant temperature via the rodiator thermoswitch. If you want to check both the speed operation of the FCM and fans simultaneously, turn the ignition on and jump different pairs of terminals on the connector for the thermoswitch. The fans should run at all speeds this way. If the ignition is not on, then the fans will not run on high speed.

Quote, originally posted by Stormgrey93 »
All my fuses check out as well.Man I am getting confused there seems to be so many things that run the fans,lol.

It's a complicated circuit, most of which is hidden inside the FCM.
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Quote, originally posted by Stormgrey93 »
When the Aux. pump runs,does it run as soon as the car is started?Or is it timed out to run once the thermostat opens?Just wondering,cause if I do wire it up I want to make sure that the coolant is flowing through it .Any help is appreciated.
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The aux pump is not controlled by temperature. It only depends on the state of the ignition switch. The pump will come on as soon as the condition is turned on. It will stay on while the engine is running. When the ignition is turned off, the pump will stay running for a timed amount. As far as I know, the time is just a single value and does not vary with coolant temperature.
If everything is hooked up and the ignition is turned on, then the pump should run. If not, and if all fuses and wiring are good, then it's either a bad pump or a bad FCM. The FCM could still operate the fans correctly, but be broken with respect to the pump. Don't use the fact that the fans run when triggered (only) as evidence that the FCM is 100% OK.
 
Re: Is there a relay or fuse that operates the aux. waterpump? (VgRt6)

Quote, originally posted by VgRt6 »
The FCM could still operate the fans correctly, but be broken with respect to the pump.

Exactly. Mine was.
 
Discussion starter · #13 ·
Re: Is there a relay or fuse that operates the aux. waterpump? (VgRt6)

VgRt6 said:
The speed is controlled by the FCM, but is also triggered by coolant temperature via the rodiator thermoswitch. If you want to check both the speed operation of the FCM and fans simultaneously, turn the ignition on and jump different pairs of terminals on the connector for the thermoswitch. The fans should run at all speeds this way. If the ignition is not on, then the fans will not run on high speed.
OK.I checked the thermoswitch by jumping and it kicked the fans on at different speeds. So,would it mean that the problem therefore lies in the FCM?Damn,I think I'm starting to confuse myself,lol.
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Discussion starter · #14 ·
Re: Is there a relay or fuse that operates the aux. waterpump? (Stormgrey93)

I did run a hot and ground to the pump itself and the pump did operate,so I know it's good. I was hoping this would all be much more simpler than it is,lol
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Plus I am/was hoping it wasn't the FCM since it cost so much.
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Re: Is there a relay or fuse that operates the aux. waterpump? (Stormgrey93)

Looking from the front of the car at the fcm pictured ealier in this thread. The fuse on the right is the auxillary water pump fuse. Hope this helps.
 
Discussion starter · #17 ·
Re: Is there a relay or fuse that operates the aux. waterpump? (VgRt6)

Quote, originally posted by VgRt6 »
It sounds to me like the pump portion of the FCM is bad. This is assuming that all fuses and wiring are good.


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Just great,lol.I am thinking you are right.I was really hoping it wasn't the FCM. May be easier and cheaper to just run my aux. pump wired to the ignition,lol.Any suggestions on which wire I could do this to?Thanks all.
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Discussion starter · #18 ·
Re: Is there a relay or fuse that operates the aux. waterpump? (98vw-vr6)

Quote, originally posted by 98vw-vr6 »
Looking from the front of the car at the fcm pictured ealier in this thread. The fuse on the right is the auxillary water pump fuse. Hope this helps.

Inside the FCM?
 
Re: Is there a relay or fuse that operates the aux. waterpump? (Stormgrey93)

Quote, originally posted by Stormgrey93 »


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Just great,lol.I am thinking you are right.I was really hoping it wasn't the FCM. May be easier and cheaper to just run my aux. pump wired to the ignition,lol.Any suggestions on which wire I could do this to?Thanks all.
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Or you could just go without the pump operating. A bunch of people do this without any obvious issues.
 
Discussion starter · #20 ·
Re: Is there a relay or fuse that operates the aux. waterpump? (VgRt6)

Yeah,thats an option.I have been driving w/o it for awhile.I did notice that inside my overflow that the coolant seems to just kinda trickle out of the hose into it.Wondered if it was because of the pump or if I may have a blockage somewhere?I already changed the whole thermo.housing,crack pipe,thermostat and all.Even have a waterpump to put in. Man is there anything cheap on these cars,lol.I do appreciate your help on this. http://****************.com/smile/emthup.gif
 
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