11 replies to this topic

[A-GAME]

Right- thanks to all your suggestions I've been able to fault find just why my vxt fan doesn't kick in...

- Relay and fuses checked/replaced- STILL NOTHING
- fan linked directly to 12v feed- FAN WORKING/OPERATES FINE

Am I right thinking it therefore must be the thermostat switch which turns the fan on/off?????
Do you know where is this located as I'm thinking I can bridge the wires to at least keep it on permanently when I take it for my MOT?

Thanks in advance!
Andy

[techieboy]

As far as I know, there isn't a "switch" that turns it on as it's controlled by the ECU and relies on the coolant temp sensor readings. When the ECU decides it's too hot, on it goes.

[A-GAME]

As far as I know, there isn't a "switch" that turns it on as it's controlled by the ECU and relies on the coolant temp sensor readings. When the ECU decides it's too hot, on it goes.

Thanks- The coolant temp sensor seems to be doing it's job fine, and the fan works off a direct feed. Is it worth unplugging the temperature sensor or trying anything else? I've reset the ecu and will swap the fan fuse (NO 12) and also the relay again- but this has me pretty much stumped!!!

Any ideas?

[Roberty]

I've reset the ecu and will swap the fan fuse (NO 12) and also the relay again- but this has me pretty much stumped!!!

Any ideas?

I have seen that some suggest that the fan kicks in at 97 deg C but when I asked a similar question the other week I was told that it doesn't kick in until 106 deg C (like the Elise).

Might be worth confirming at exactly what temp it is mean't to come in at?

It may work fine but you've never actually got it hot enough to kick in!

[A-GAME]

I've reset the ecu and will swap the fan fuse (NO 12) and also the relay again- but this has me pretty much stumped!!!

Any ideas?

I have seen that some suggest that the fan kicks in at 97 deg C but when I asked a similar question the other week I was told that it doesn't kick in until 106 deg C (like the Elise).

Might be worth confirming at exactly what temp it is mean't to come in at?

It may work fine but you've never actually got it hot enough to kick in!

Fan usually kicks in at 95/96 deg I was reliably informed. However, the 106 degrees mark rang a bell in my head too (but wasn;t sure if this was for the vxt or NA) so I did reluctantly let it reach 106/107 degrees whilst carefully watching the tank/pipes, and it STILL didn't come on!! Then shut it down asap!

[Roberty]

Fan usually kicks in at 95/96 deg I was reliably informed. However, the 106 degrees mark rang a bell in my head too (but wasn;t sure if this was for the vxt or NA) so I did reluctantly let it reach 106/107 degrees whilst carefully watching the tank/pipes, and it STILL didn't come on!! Then shut it down asap!

Might need to check the state of your wiring then, could be a loose connector or cut wire somewhere?

Other option is to wire a switch in and control the fan yourself.

Edited by Roberty, 13 August 2009 - 11:43 AM.

[SteveA]

Just out of interest, which fuses did you check? Number 12 is the one to look at. If that is fine get yourself a continuity tester and check the following; X31 pin 29 to X2 pin 13 X2 pin 13 to fan power plug.

Edited by SteveA, 13 August 2009 - 01:45 PM.

[Ren]

Fan usually kicks in at 95/96 deg I was reliably informed. However, the 106 degrees mark rang a bell in my head too (but wasn;t sure if this was for the vxt or NA)

As far as i am aware, 96 degrees is for the turbo and 106 degrees for the N/A.

[mcarrick69]

I'd let it go to 112-115 degrees and if it doesnt kick in then have a very clear road at hand that you can drive down briskly. I think it will come in by then. sure its taken till over 106 to kick in on mine.

[A-GAME]

I'd let it go to 112-115 degrees and if it doesnt kick in then have a very clear road at hand that you can drive down briskly.

I think it will come in by then. sure its taken till over 106 to kick in on mine.

surely yours is a NA rather than a tubby though??

[A-GAME]

Just out of interest, which fuses did you check? Number 12 is the one to look at.

If that is fine get yourself a continuity tester and check the following;

X31 pin 29 to X2 pin 13

X2 pin 13 to fan power plug.

Thanks- yeah I've tried/replaced fuse 12 and I'mm trying to get hold of a continuity tester off an electrician friend today. Excuse my ignorance but how do i check the fuse/pin combinations you've mentioned when i have it??
thx
andy

[SteveA]

The ECU has two connectors going into to these are X31 & X32. One of them (X32 IIRC) can't be removed without drilling out a security bolt. Uplug the X31 and count along to pin 29. Then measure resistance between there and the power wire (loom end) of the fan plug. You will deffo need some long bit of wire to test it. If that shows a reliable resistance there is no break in the loom so check the earth side of things. If it shows nothing track down the X2 (under the front bonnet IIRC) and unplug it. Test resistance as in my last post. This should narrow things down. A copy of the TIS will help as it has wire colours and connector locations.