Radiator fans constantly on

[MattLG]

While fiddling with my stereo a couple of days ago I heard the radiator fans on, even though I hadn't switched the engine on. It was dark but I had a quick look at the engine bay and noticed some disconnected wires and assumed that was it.

In daylight however, those wires seems to come from a HKS Twin Power Ignition amplifier that I didn't know was there. It appears to be pretty much completely disconnected and I assume that's nothing to do with it anyway. I can't see anything else disconnected.

Any ideas as to what might be causing this? Also, is it worth getting the Ignition Amplifier reconnected? What do insurance companies generally reckon to them?

Cheers.

MattLG

[MattLG]

SC Mk1 BTW

[Lauren]

I can't see these two things being connected in any way.

About the only reason the rad fans would come on if the engine isn't on would be if you had been driving it minutes before and the cooling system was still hot. Other than that i would expect it to run all the time then if there was a fault, which would be most likely in the temp sensor which is on the rad. If it is disconnected this might cause the fans to run all the time (much like if you disconnect the engine bay fan sesnsor which will run constantly if you disconnect it from the sensor).

I don't really think its worth connecting this HK$ igniter up tbh, but if you did i'd doubt the insurance would be that interested, but you should declare it.

[Dave Goodhand]

When I was re-wiring my MK2 (maybe different, but I'd expect the fundamentals of the circuits to be the same (being Toyota) I got to a point where the rad fan was always on (once the ignition was turned on) I found it to be a short ciruit where I had connected some of the ignition wires to get power for various things in the cockpit.

The rad fan seems to be on the same circuit as the ignition circuit, and the stereo power one. I would say check these to see if you've tapped into any wires causing a short circuit.

[MattLG]

A definite possiblity then. I didn't notice it until I was putting in a new stereo so it may well be that.

This could be a nightmare to track down

MattL

[Jayng]

Hi Matt,

Is this the first time that you`ve had the ignition on without the engine running?? Maybe the fans have always been on even when the engine is cold and you haven`t noticed it before because of the engine drowning out the fan noise.

I`m asking all this and I don`t know if it helps, but on the MkIIs there is a sensor clipped onto the underside of the engine lid. If unplugged, the fans will come on constantly even with just the key switched to ignition and engine not running. Maybe worth you checking this out before you go over the whole stereo wiring.

[MattLG]

I'll check that out too. I've only had the car since september so it's possible it's always been like that and I've just not noticed.

MattLG