Waterpump Sensor

prooutlaw · 05-12-2005, 08:04 AM

Where is the Waterpump Sensor located for the electric Waterpump on a 944 Turbo ?
My Waterpump runs all the time , it will not shut off unless you disconnect the Power.
Is it the Sensor that mounts on the Turbo ?

ae1969 · 05-12-2005, 08:08 AM

THere is a cooling line running from the coolant tank across the front of the turbo.....over to the passenger side of the housing (center section) of the turbo.
On top you will see a sensor with a wire on top.

The wire gets grounded which gets the pump moving....... Check to see that the wire is not grounding on something.

You can run without the pump if you need to until you fix it.....(disconnect the wire)......Just run the car for a couple of minutes before shutting the car down especially after spirited runs.

prooutlaw · 05-12-2005, 08:16 AM

The wire that comes off the Sensor goes into the Harness , so i can not see if it is disconnected on the other end.
How else can i check it ?

ae1969 · 05-12-2005, 10:07 AM

It should have nut to hold it on the sensor.... (remove the wire from the sensor)

Otherwise I would just cut the wire

You can easily use connectors later if you replace the sensor.

Now if you cut the wire and it still running ....... you have a short in the harness........ yuck

DannoXYZ · 06:35 PM

The temp-sensor is actually a thermo-switch, it's either on or off. When it activates at 235-degrees F, it's ON and grounds the wire on the harness. That's what activates the relay. So in the normal state, or disconnected altogether, your water-pump shouldn't run more than the 30-seconds that is determined by the timer in the relay.

So if you disconnect the plug from the sensor and the water-pump stops, then the sensor's bad. You can get a new one from NAPA auto-parts: Turbo coolant switch.

This is a lower-profile unit that works with large turbo upgrades.

However, if you've already disconnected the plug from the sensor and water pump still runs, then you've got a short in that wire somewhere. Trace all the way back to the firewall and see if it's grounding on a metal edge somewhere...

Dan in Pasadena · Dan in Pasadena's Garage

I think this thread probably answers one of the questions I just put in a new post.

Can someone post a picture of the temp sensor/fan switch (whichever is the correct term) installed? AND where the wires connect into the harness? Thanks very much.

DannoXYZ · 03:23 PM

Here's a picture of where the turbo temp-sensor is located:

And with the intake-manifold removed:

And a lower-profile aftermarket unit you can get at NAPA
that doesn't run into the bottom of the intake-manifold when using larger aftermarket turbos:

You can test the pump-relay by sticking a nail into the female plug and grounding it on the intake-manifold. The pump should run for 30-seconds and shut off.