cooling fan doesnt automatically cut in

[SweetWagon]

Ok i have had this problem since i got the Vn, but today i got stuck in peak hour traffic and the temp rose to about 1 bar below HOT and the cooling fan doesnt cut in.... I know what your going to say, i should have put the A/C on and control it manually, but i got to fix that as well. Anyway when my A/C was working, the fan would cut in but it still doesnt work automatically. So what would cause it to stop cutting in automatically??

[azkwazere]

If its a SI VN thermostat is at the back of the engine, VNSII - VP the thermostat is at the front. Thats what it will be. Was mine anyway. Your stat will be ceased and the ECU wont know to turn it(thermo fan) on. When its running... feel each side of the engine, one will be colder than the other as the thermostat isnt allowing coolant to pass properly.

hope it helps.

aZk.

[2greedy]

Does you air con die too when this happens? cause if it does it will most likely be 1 of the relays under the bonnet cause mine done it the cooling fan went first then the aircon compressor wouldn't kick in and it was a series of a relay and fuses.

[VNPOWER]

Either its not plugged in or you're coolant temp sensor has had it, thats what tells the cpu when to turn the fan on.

The dash temp meter has its own sensor..

[SweetWagon]

Firstly thanks for all your replies, i been heaps busy with work lately, anyway

If its a SI VN thermostat is at the back of the engine, VNSII - VP the thermostat is at the front. Thats what it will be. Was mine anyway. Your stat will be ceased and the ECU wont know to turn it(thermo fan) on. When its running... feel each side of the engine, one will be colder than the other as the thermostat isnt allowing coolant to pass properly.

hope it helps.

aZk.

thermostat was changed recently, i couldnt be it anyway cause as i said it got to 1 bar below HOT and didnt cut in.

Does you air con die too when this happens? cause if it does it will most likely be 1 of the relays under the bonnet cause mine done it the cooling fan went first then the aircon compressor wouldn't kick in and it was a series of a relay and fuses.

no, everything fine with air-con. the engine fan still comes on when the air-con is switched on so that rules out any fuse/relay/wiring.

Either its not plugged in or you're coolant temp sensor has had it, thats what tells the cpu when to turn the fan on.

The dash temp meter has its own sensor..

i think you have been the closest so far, the only thing is coolant temp sensor seems to be working fine, economy wise anyway. I will try to a resistance test on it today to rule it out. after i fix my fan speed switch today (so i again manually control the engine fan via aircon), i'll run it to over half temp and see if that does anything, but it didnt before so i'm not keeping my hopes up.... i did a diagnostic test and the ecu didnt show any temp sensor fault either.

thanks again for the replies.

[2greedy]

well my engine fan would come on too when i turned the aircon on but it still turned out to be a relay and fuses?

[lilkel]

i had the same problem with my VP and it was under the bonnet where the relay plugs in had melted and the relay wasn't contacting to the wiring properly at first it would work every now and then but eventually it wouldn't contact at all!!!

[SweetWagon]

ok i have fixed my A/C so i can again manually control my engine fan, Just a quick question, at what temp if the fan "supposed" to cut in?? so then i can heat it up and see. cheers

[VNPOWER]

mine comes on just after it goes over the third line from the bottom.

[SweetWagon]

cheers i'll go out for a drive today to see, thanks.

[SweetWagon]

Its all sweet now, comes on exactly on the 3rd line as you said. No more manual controlling the temperature for me now next thing is to fix these sticky gauges