[Mk2] [Turbo] Radiator Fan always on - even with Key removed

[mtechmatt]

Hi everyone

had a good google -lots of rad issuesbut this one is probably a new one?

Car has had gearbox change, was fine before.

Car started up (battery was dead so used booster) and ran fine then just switched off. And rad fan came on.

Now the rad fan is always on (even with key removed) indicator lights are on, but dim (not flashing), and although I get lights on the dash the car wont run (it cranks of a starter switch)

The SAFC and ACVR in the car are not powering up. Almost like the alarm isnt disarming + the fan fault.

Anyone seen this before?

Cheers in advance,
Matt

[Peter Gidden]

Start by checking what was disturbed when gearbox was changed:

Assuming engine not removed, battery terminals and main earth between gearbox and N/S chassis near engine mount.

[mtechmatt]

Peter,

Just checked - they look good. Engine cranks strongly (it has a 'push button and relay' in there and cranks strongly so can ssume engine ground is ok.

I think it might be an alarm issue as the alarm is now 'not working'.

Only just got the car today from a friend (though have known of it for years!) He did the gearbox change yesterdya, after we brought it round to my unit from storage for last 3 years) we got it running, I handed him some money and it just cut out - he is not automotive electronicy beyond mechanics. I am electronically minded (its my job) so if this isnt a common issue (with the tell tales given) then I may need to start checking things.

I am thinking alarm (or some hidden turbo timer) type of issue though...

Matt

[2mad]

In some cases turning the car on and the fans coming on is normal (mine did it) turning the car off and they keep going is not (unless turbo timer) , (but engine would still run) very odd mate .

[Peter Gidden]

Immobilser when not disarmed can cause the symptoms you mention.

Assuming all alarm wiring is in car as opposed to engine bay, would appear not to be related to gearbox change.

[mtechmatt]

2mad - yes aware of that one - dont think its the issue I have though

Peter - the car wa sin storage for several years. After gbox chnage it did indeed start and run, the alarm worked;' and the AVCR etc would only powr up once alarm disarmed.

Then as i said whilst running it on the ramp, it just cut out, and now has the faults - so indeed although it may not be gbox related (ie it did run after) I think you are onto something with immobilsor as now alarm does not work, SAFC/AVCR does not power up, and pressing alarm button does naff all - that and the idnicators are on but dim...

What do you recommend to probe to confirm an alarm issue? Is there a main EFI relay point somewhere I can see if it is coming live (or give it a feed so it does)?

I also assume that this car does not have factory immob so I could just take dash apart, locate alarm box and bypass it all?

Regards,
Matt

[2mad]

It has to be immobilizer related ... or .. well there is not an or .. why would this happen .. somethings powering up the fans ignition off .

[mtechmatt]

Yep... so where to check

I assume there is an OEM immobo in there or would it just be the aftermarket alarm in there?

Matt

[2mad]

I'm at a loss mate .. this is a new one on me ... in for the answer if it happen s to someone else ... sorry

[2mad]

Probably aftermarket for the immobilizer.

[thomp1983]

Efi relay is in rear fuse box. What revision is the car?

[mtechmatt]

Its H reg so I believe Rev2 but am no MR2 expert

Pics are on my facebook but I am not allowed to post URLs yet?

Cheers
Matt

[mtechmatt]

Ok good news

Went through wiring and stuck 12v to drive the EFI relay (and obviously everything 'car side' of the immobilizer - everything works properly fans etc engine runs yadda yadda.

So it looks like the immob is powering something but not the whole keyside properly. For now its all good on a toggle switch so will go through it, either bypass, fix or replace the alarm and we have a winner

Cheers chaps

For googles sake:
MR2 Turbo fans always on even without key
mr2 fans always running no key

[2mad]

Good for you .. well done mate

[mtechmatt]

Cheers bud

Was a b*gger but got there now.... just having some paint and tidy up on the old girl now