VS commodore thermo fan not working

[pete001]

Ok I just went and did the coolant temp sensor trick and it worked, The fan came on just like brett said it would. So im guessing that the next step is to pull out the computer and check that for signs of charring.[/QUO


Just pulled the computer out and check for charring or anything abnormal, but it all looked fine and in very good condition. May have to just take it to an auto electrician.

 

[Immortality]

try to get hold of another PCM..... beg/borrow/steal etc

 

[delcowizzid]

the dash may be reading wrong theres 2 different sensors for the vs dash one shows higher temp than in reality and can make it look like the fans are never going to turn on

 

[Brett_jjj]

If your cooling fan came on when the temp sensor wiring was removed from the sensor,then the fan system,its wiring ,relays and ECU/PCM are all working ok.It wont be the ECU/PCM causing the problem if the fan comes on during this test.I couldnt get the cooling fan to come on at all when my ECU/PCM burned out,even with the temp sensor wiring removed from the sensor it wouldnt go.Id say its just like delcowizzid said above,some temp gauge senders just read higher than others,a lot of people on here have VS's where the thermo fan comes on at around 3/4 temp or more,with my VS the low fan comes on at about half way on the temp gauge and drops it to around a quarter .I dont think Id like to have the temp gauge reading 3/4 at normal operating temp.I would be worried I wouldnt notice it in time if I got a real overheat situation..Next thing Id be doing is just let the car sit idling and keep a good eye on the temp gauge and let it get to 3/4 or a bit more and then see if the fan comes on.

 

[pete001]

Ok I just went and tested it again by running the car on idle after about 3/4 of an hour it finnaly got to one notch above half and I couldn't believe it the fan cut in. I still think that that it should cut in a little earlier but it could also be the temp sender sending a faulty reading so I will replace that as well. Now to all you fantastic people out there who offered me great helpful hints to fix this problem especially Brett_jjj THANK YOU. I couldn't have fixed it with out you so cheers.

 

[QuickVRII95]

I Overlooked The Thermo Fan Turning On When You Use The AC... Yeah, It's The Coolant Temp Sensor... They Normally Differentiate, Depending On Genuine Or After-Market... Always Use Genuine Sensors On Commodores...

 

[astormsau]

There were 2 gauge temp sensors for the VS, the one fitted to most VS's will mis-represent the engine coolant temperature - it was a hangover from the VR but because mounted in a different location it over-states the engine temp so to speak... Go to Holden and spend $15 on a new guage sender, fit it (sits right next to the ECU coolant temp sensor) and then tell us how you go.

Drew

 

[pete001]

I just replaced the gauge temp sensor today and the now my temp gauge reads a little higher for some reason. so now in total I have replaced the guage temp sensor and the coolant temp sensor, both the low and high fan relays. and even tho the fan does come on now its not until the temp gets to 3/4 and to me that's a bit of a worry so I might have to go replace both of those sensors again with genuine Holden parts. I will repost what happens after I have done that. Fingers crossed.

 

[astormsau]

I could only recommend using the genuine parts. Holden dealer should know there were 2 models of senders for the VS, one was an early one and one was a later one, you want the later one which reads correctly. I was in the same situation as you, fan would only come on about 3/4 up the gauge... now it comes on at just over half once I replaced the gauge sensor with the revised part.

Drew

 

[RX25SE]

When you say the fan is comong on is it high or low speed?

The low speed relay is switched on by the BCM first. If the temp continues to rise, the PCM takes over and switches the high speed relay. (maybe someone could post the switching temps, Im on a differnt computer)

Make sure the earth point above the battery is clean. Remove the nut and emery all the earth wires including the body to ensure a good earth.