Help, overheating

[discostuee]

Hi

Now hopefully someone can help me,
i pruchased a 91 Vn V6 Commodore. The engine has been replaced with a v6 Vp engine, Now i have a problem with the thermo fan not turning on and it over heats. Ive done the paperclip trick and the only error was the MAT (manifold Air Temp) and the thermofan came on, but when i removed the paperclip the fan never came on again till i put the paperclip back in, So i replaced the sensor, still the same, so then i replaced the Coolent temp sensor (not temp sender) and still the same problem, someone then suggested that the ECU migh be faulty so i replaced the ECU with the eact same model and yet again still the same problem, But still same problem, by hte way the Aircon wont work either which im guessing is related to the fan issue. Ive checked Fuses, relays and all is good. HELP me please with ideas.

Just one thing left im thinking is, is the VN ecu different to the VP ecu as i think its got the VN ecu still in it?

Thank in advance

[Benboy]

Apart from a faulty sensor 'somewhere' in or on the engine, check that the plug connecting the fan is securely in place and connected to the wiring harness. If not neither the fan or A/C will work. You should obviously check all your fuses.

[J_D]

Mine had the same type of problem which turned out to be the fan fuse plug had melted from arcing and wasnt making positive contact with the fuse, I bypassed the fuse which fixed it for a while but it started playing up again so I replaced the temp sensor which didnt fix it so I bypassed the whole system with a switch on the dash so I can turn the fan on any time I like, now I dont have to worry about sitting in traffic.

The fan should switch on whenever the aircon is on. If it doesnt turn on the aircon will still work as long as the car is moving but will stop working when the car is stationary. If your aircon doesnt work at all (moving or not) then there is some other issue at play other than the fan, the most common ones being no gas in the system, faulty clutch on the A/C compressor or a worn A/C compressor.

[totq]

Hi

Now hopefully someone can help me,
i pruchased a 91 Vn V6 Commodore. The engine has been replaced with a v6 Vp engine, Now i have a problem with the thermo fan not turning on and it over heats. Ive done the paperclip trick and the only error was the MAT (manifold Air Temp) and the thermofan came on, but when i removed the paperclip the fan never came on again till i put the paperclip back in, So i replaced the sensor, still the same, so then i replaced the Coolent temp sensor (not temp sender) and still the same problem, someone then suggested that the ECU migh be faulty so i replaced the ECU with the eact same model and yet again still the same problem, But still same problem, by hte way the Aircon wont work either which im guessing is related to the fan issue. Ive checked Fuses, relays and all is good. HELP me please with ideas.

Just one thing left im thinking is, is the VN ecu different to the VP ecu as i think its got the VN ecu still in it?

Thank in advance

The ecu controls when the fan should come on or off, depending on temp signals from the coolant temp sender....check wires between those 2 circuits.
But I reckon a consultation with your local mechanic/auto elect may have saved you a lot of time and possibly money than what you have been doing so far....