Thermo Fans Not Working Vp calais

[DONKEYFAPPER95]

Alright so, my fan wont come on causing my car to get hot, i have hardwired it to a battery to see if it was the fan itself, the fan works. i replaces the sensor underneath the alternator, still no fan kicking in, i have checked all fuses, (switching the horn with the fan) and still not working, i dont want to run a switch cause its a case of cbf, if worst comes to worse i will, id like some feedback about the problem, im also aware that it could be a computer issue, so yeah love some feedback

 

[hi_ryder]

there was a recent thread started on this, have a read and if you still have some questions post away. also if all else fails it could be a problem with the ECM not telling it to come on.

http://forums.justcommodores.com.au/vn-vp-holden-commodore-1988-1993/216613-car-overheating-thermo-fan-not-working.html

 

[FXST01]

Checked the relay near the battery? Swap it over with the headlights.

 

[Cheap6]

Easy enough to see if the ECM is trying to switch the fan on. The fan relay has a switching side, with power and ECM connections and switched side with power and fan connections (that's the side with the thicker wire). There's even a little wiring diagram on the side of the relays.

The white wire with blue stripe on the switching side is earthed by the ECM to switch the fan on. You can get the ECM to switch the fan on by disconnecting the CTS, turning on the A/C or putting it into diagnostic mode with the paper clip on the ALDL connector (same as checking for fault codes) and turning the ignition on (not running).

With the ECM set to switch the fan on, if you lift the relay out of the connector a little way you can get a test light to the wire that goes to the ECM. That should have battery voltage to it until the ECM switches the fan at which point it will drop to 0V (earth). If you do see that, then there's something wrong on the switched side of the relay. If you don't then it's either that there isn't battery voltage to the relay or the ECM isn't switching it. It will be fine to jumper to earth that W/Blu wire with the ignition on as a test instead (or as well). That's what the eCM is or should be doing and will tell you that there is battery voltage at the relay.

The ECM pin that switches the fan can be found by matching the wire colour (W/Blu) at the ECM connector. I'm going to say it's C10 but don't hold me to that.

 

[DJ_Cosmic_Fire]

Alright so, my fan wont come on causing my car to get hot, i have hardwired it to a battery to see if it was the fan itself, the fan works. i replaces the sensor underneath the alternator, still no fan kicking in, i have checked all fuses, (switching the horn with the fan) and still not working, i dont want to run a switch cause its a case of cbf, if worst comes to worse i will, id like some feedback about the problem, im also aware that it could be a computer issue, so yeah love some feedback

IMO ECU is unstable - Refer to ^ if you understand it, if not get a reco'd ECU with warranty for VN/VP V6/V8 (Delco 808) GM-A01 which are the same - even Astra LD/ Camera JE, auto or manual). Keep your stock MemCal & presto, everything will be working again. I keep a few ECU's & many more performance MemCals around JIC or JFK, all are completely ready for swap over if need be or I feel like it. Key is to have spares of all sorts for your vehicle at hand for when the situation arises (which it does), many moving parts = ongoing checks/maintenance..

 

[Pub247]

if you put te ecu in diagnostic mode the fan should come on if not then its ecu related if all the fuse and relays check out ok

 

[VPRob]

Which sensor did you replace? There's 2. One feeds the dash gauge and the other does the computer, thermo fan etc.
My thermo fan wasn't working recently and it was just poor contact at the plug next to the fan (where you disconnect it to take it out). Check that out before you do anything more complex
PS the fan should only be needed when doing a lot of sitting in traffic