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Radiator fan switch question (clutch fan replacement)
I replaced the clutch fan on my '86 a year or two ago and used a temperature switch spliced in the upper radiator hose to trigger the relays for it. That location is less than ideal for a cooling fan switch, and I was thinking of ways to try and use the stock radiator fan switch location to activate both the new electric fan and the old auxiliary fan.
944 Turbos have a 2 stage temperature switch in the radiator that gives a switched ground at 92* and iirc 102*. It seems to me that if the switch has the same thread size as the 928 aux fan temperature switch then it could be used to activate the main cooling fan at 92* and then the aux fan at the higher temperature.
Does anyone know if the 944 switch will thread in to the 928 radiator or see any reason this wouldn't work?
I've thought about as well. I wouldn't imagine they'd be different in thread size. Find a second hand one and see.Or go over to the 951 forum and ask if someone has a bad one they don't need.
I deleted the belt driven fans years ago and installed the dual Ford Contour fan set up. I deleted the front AUX fan at the same time as the dual Ford fans both ran when the AC was on.
Recently I switched to the Hayden digital dual fan controller that came with a threaded temp switch versus a in the fins temp switch. I bought an adapter and installed it into the Aux electric fan temp switch port on the radiator, The Hayden digital soft starts the fans and runs them on High when AC is on,
Thanks for the info. Looks like it will work just fine. I Don't really want to replace the electric fan I have in the car now. It's a big single unit and has no problem keeping the temp steady even stuck in south Florida traffic, I just want to change the location of the temp switch to the radiator outlet to keep the fan from coming on before the engine is fully warmed up.
I'll post back when I have the dual temp switch wired in.
Porsche, sensibly, put the fan switch near the outlet of the radiator so that the fans come on only when additional cooling is needed. Putting the sensor in the upper hose means the fan(s) come on when the thermostat open. No "credit" is given for cooling when driving at highway speeds.
Electrical fans became popular as transverse engines don't provide easy mechanical fans and that they save power (energy) over a constantly-running mechanical fan. There are thermostats to reduce fan drag in mechanical fans but that's not as good as turning an electric off. There's no advantage for the electrical fan, power-wise, if it's running constantly as the alternator and fan motor aren't as efficient as just running a belt.
The radiator tank thread is M22x1.5. There are MANY switches that will fit this, including some with 2 sets of contacts at different temps. Look here for a big selection :- http://www.tridon.com.au/products/Tr...o-fan-switches There will also be many on ebay.
I have a SPAL dual 11" assembly in my car, triggered by a top hose switch. I find the temp gauge indicates whats happening more in sync with the fans operating with the top hose switch.
944 and 928 switches are the same thread size.I have used a 944 dual temp switch in my 79 for decades,using the lower temp contacts to turn on the electric fan I installed in place of viscous drive mechanical and have the OEM electric booster fan hooked up to the hi temp contacts.
Anyone know if this just screws on without having to drain the radiator of coolant?
Also anyone know if this will fix the non working temperature gauge on the instrument cluster? I've already replaced Thermo stat 1 and 2 sensors.
The temperature gauge on the instrument cluster gets its temperature from 92860620101 which is on top of the regulator housing above the temperature time switch. It has two spade connectors, one large and one small, that connect to it. The one you have pointed out is the aux fan switch that will turn on the electric fan for additional cooling and it will not help the with the temperature gauge working. It can be changed will coolant in the system, but you have to be quick to prevent too much leaking out. I have done this a few times without losing too much coolant as long as you are ready with the replacement in hand.
Last edited by Flinstigator; 01-25-2024 at 11:11 AM.
The one with the red arrow is the part. You may start with replacing the spade terminals since they look a little corroded and the insulation looks a little suspect. You can replace those and see if that fixes the issue. There is a test in the WSM to test the sensor to see if its functioning. The fan switch in the radiator controls the temperature that the electronic fan comes on. I would start with replacing the spade terminals and inspecting the wires. If could also be the connections in the ribbon cables going to the POD or something internal to the gauges.
Can anyone help with the correct connections?
The blue arrow spade houses the two light blue connection wires.
the red arrow spade houses the single brown wire.
Which connect to the "L" connector?
Which connects to the "R" connector?
The auxiliary fan does not turn on.
I have disconnected and put the fan's connectors directly to a 9v battery and the fan blanes turned(albeit slowly) so i dont believe its the fan.
Any help much appreciated.
12-05-2017, 04:11 PM
Radiator fan switch question (clutch fan replacement)
