Doing the yearly "spring" coolant flush and found that my thermo switch is pitted and looking ready for replacement. I got a stock temp switch and installed it. Fan isn't switching on. I jumpered wires on the thermo switch and the fan kicks on strong. I supply power to the fan via the battery and the fan kicks on. I hook up an aux switch, tieing into the thermo switch wiring directly, and the fan kicks on.
Fuse is good. Relay is good. Fan is good. 81, non AC, single speed fan. Any suggestions as to where I should look now?
The circuit on a non-ac car is simple.
Battery to Radiator switch, Radiator switch to motor.
Your Fan will only come on if the temp at the switch is above Kammy will correct depending on the switch 95 or 105C.
If you are driving the car in cold weather the fan may never come on.
Highest suspect is the switch if you placed a jumper wire or paper clip between the contact pins on the radiator switch connector and the fan runs it is either the switch or you don't have the car up to temp.
There are 195 t-stats that are normal and 180 that they will give you at the parts store. The T-stat and the Radiator switch have to match. So the t-stats are rated at 195F and the switches at 95C or 102C. If you have a full open t-stat at 180 degrees, that isn't close to the 95C or 102C
195 t-stat is 90C
180 t-stat is 82c
95C switch is 203F
102c switch is 215F
So your switch may never close.
You also should of tested the new switch as new switches are bad out of the box. Find the Rating on the switch, place a multi-meter measuring the resistance between the 2 pins. Place in a pan of water with a candy thermometer or similar Keeping only the Brass end in the water. Raise heat on the pan to the rating of the switch if the water gets to the rated + or - 1 to 2degrees, and the switch doesn't short or go to ZERO OHMS bad switch.
Ah hah! 90*C*. That's the issue. I do have a lower temp thermostat so I'll grab my extra low-temp radiator switch and drop it in. I was reading it as 90F. Talk about a simple fix, thank you sir. I'll test them both out of the car as well.
Cabby-info.com has a wealth of information. Kammy has this spelled out in http://www.cabby-info.com/cooling.htm#Thermostat
Ok it is a Cabriolet site, No Diesels stuff, but the CIS and Digifant is spot on as well as the general how to's and fixes that go both hard and soft top... It is a Bookmarker.
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Related Threads
?
?
?
?
?
Volkswagen Owners Club Forum
448.1K posts
78.8K members
Since 2006
A forum community dedicated to all Volkswagen owners and enthusiasts. Come join the discussion about performance, TDI, modifications, troubleshooting, maintenance, and more!