Radiator fans Wiring diagram help

Re:Radiator fans Wiring diagram help (sprigs)

Sat, 01 Dec 2012 23:03:26 GMT

My theory is, it could be the immobilizer not supplying power to the amp and other components. With no power to the amp means the fans run on full speed. Though I don't understand why it doesn't give power to the amp when you turn the immobilizer off (when the key is in IGN ON position). Maybe its the design of the alarm to not to complete the circuit or give power until the engine is running as an extra precaution?

Re:Radiator fans Wiring diagram help (MRTurbo)

Fri, 30 Nov 2012 09:26:40 GMT

for some reason when I got my new alarm installed, the thermo fans turn on when IGN is ON and immobiliser is active, but when I press the fob button to disable the immobiliser (then start car), fans go off and work normally... weird.

Re:Radiator fans Wiring diagram help (robk)

Fri, 30 Nov 2012 00:03:48 GMT

Nice one :-)

Re:Radiator fans Wiring diagram help (sprigs)

Thu, 29 Nov 2012 21:20:10 GMT

Just an update, got a replacement a/c amp from ebay, installed it, now the fans are quiet :) I guess its fixed

Re:Radiator fans Wiring diagram help (Road and Track)

Mon, 29 Oct 2012 08:45:05 GMT

i've had numerous cars with simialr faults. there are several versions of the a/c amplifier and i would strongly recommend you remove it and get the part number off it before ordering. the location changes slightly between models, but its always on a bracket up behind or beside the a/c box under the glovebox.

Re:Radiator fans Wiring diagram help (sprigs)

Sun, 28 Oct 2012 19:20:55 GMT

oh yeh just noticed that your car is a 1990 the locations should be the same but the part number will be different, since they changed the air con system after the 92 models.

Re:Radiator fans Wiring diagram help (robk)

Sun, 28 Oct 2012 19:15:38 GMT

Thanks for all your help mate!
Now I have plenty of things to check once I get a chance.

Re:Radiator fans Wiring diagram help (sprigs)

Sun, 28 Oct 2012 18:59:17 GMT

Not too sure myself but if i have to guess it just turns on/off diff parts of the air con system (inc rad fans) based on the signals it gets from the sensors/switches in the system. Its located on the passenger side, behind the heater bulk (sh!t a$$ location). Its attached to a bracket which is screwed onto the heater bulk, just unscrew the two screws, once you do that try to loosen it and disconnect the harness via feel because its quite tight down there. Once you get it out you can just unclip the top and slide the circuit board out.

Re:Radiator fans Wiring diagram help (robk)

Sun, 28 Oct 2012 16:45:11 GMT

Where exactly is the A/C amplifier? Maybe I should pull mine out and have a look regardless of what else I check. All I know is it's under the dash somewhere.

Re:Radiator fans Wiring diagram help (sprigs)

Sun, 28 Oct 2012 13:43:31 GMT

robk - sorry the exact online saving price is $135.28, the msrp is $173.08

cogs - whoops 'shorted' was probably the wrong word to use more like fried! Behind the circuit board where those little black chips are, there's a small area there where a few of them are burnt out. I'll post up a pic when I can, dam battery went flat on the camera.

Burnt out area is behind that circled resister.

Re:Radiator fans Wiring diagram help (cogs)

Sun, 28 Oct 2012 02:20:48 GMT

The A/C amp internals are all discrete components and it can be repaired. Mine was wrecked by an incompetent A/C mechanic trying to get a stupidly overgassed compressor to fire up by blindly pumping 12V into any connector that seemed A/C related. The fault ended up being a transistor connected to pin 10 that switches the no. 1 and 2 fan relays. A simple fix and 5 years later is still working. PM me for more info if you're interested.

BTW, the diode you mentioned is there to short out back-EMF from the relays (a high reverse voltage created when they de-energise) that would otherwise damage the transistor in the A/C amp. I think it's taped to the loom somewhere near the heater box. You don't need to find it to test it - with the relays and A/C pressure switch unplugged you can connect a diode tester to the coil connections on one of the relay plugs.

Re:Radiator fans Wiring diagram help (robk)

Sun, 28 Oct 2012 01:26:19 GMT

Oh, only $130, I thought it would be a lot more.

Re:Radiator fans Wiring diagram help (sprigs)

Sat, 27 Oct 2012 23:00:46 GMT

yeh sucks bad according to lithia toyota the amp cost $130+shipping, i guess i could just do w/o air con, till i find a second hand one.

Re:Radiator fans Wiring diagram help (robk)

Sat, 27 Oct 2012 22:24:33 GMT

Hmmm, that sucks, that's probably the most expensive of all the parts that could cause the problem. At least that explains the problem for you though!

Re:Radiator fans Wiring diagram help (sprigs)

Sat, 27 Oct 2012 21:38:43 GMT

Apparently my a/c amp's internals have shorted, which means i need a new one.