My fan override switch

[QuadCam]

what the hell does Bob A Job Boys mean? is that some british slang?

[lotusespritse]

Originally Posted by QuadCam

what the hell does Bob A Job Boys mean? is that some british slang?

Everything is on google.

http://m.urbandictionary.com/#define?term=Bob-a-job


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[sailorbob]

Unfortunately that small snippet of wiring diagram doesn't show the the connections via the ecu. e.g. A/C radiator control switch to pin 57 and A/C pressure control switch to pin 69.

[lotusespritse]

Originally Posted by sailorbob

Unfortunately that small snippet of wiring diagram doesn't show the the connections via the ecu. e.g. A/C radiator control switch to pin 57 and A/C pressure control switch to pin 69.

The AC radiator control switch in the diagram does not connect through the ECU and is able to turn on the fans regardless of what the ECU thinks.


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[sailorbob]

Maybe by breaking the A/C pressure control switch circuit it can control the fans.

[lotusespritse]

Originally Posted by sailorbob

Maybe by breaking the A/C pressure control switch circuit it can control the fans.

It can't "break" it. Once the coil of the relay is taken to ground, it's turning on the fan. There's no way to stop that, and that switch is taking it to ground. I'm a EE.


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[sailorbob]

Where is fascia splice CC located and is it a -ve or +ve supply?

[lotusespritse]

Originally Posted by sailorbob

Where is fascia splice CC located and is it a -ve or +ve supply?

Just goes to ground.

[stevem]

Having a manual over-ride switch, however it's done, is a great thing when sat in traffic jams. If I get stuck in heavy traffic, as soon as I see the temp gauge get above 90 I hit the switch and can relax knowing that I'm not going to be left in the breakdown lane with steam pouring out of the rear hatch.

Before I fitted the switch, the guage would get to 100 before the fans kicked in which made me very nervous. Sat in slow moving or stopped traffic, the coolant doesn't take long to get from 100 to 120 if the otter switch doesn't click in. Sat wondering whether your engine is going to over heat or not isn't a good feeling, especially in Aussie weather.

[sailorbob]

It would appear then that the V8 fan control for A/C is a step backwards when compared to the 4 cylinder ecu control.

[vbtodd]

This. I looked at the diagram myself thinking...they couldn't have been that dumb... Of course the way they wired up the 4cyl fan setup is not how I'm used to seeing that GM ECM wired either. Their thinking is just *different*

[lotusespritse]

Originally Posted by sailorbob

It would appear then that the V8 fan control for A/C is a step backwards when compared to the 4 cylinder ecu control.

I also installed a fan override switch in my SE because it also let the temp rise too high for my comfort.


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[sleekgt]

Originally Posted by stevem

Having a manual over-ride switch, however it's done, is a great thing when sat in traffic jams. [snip]
Before I fitted the switch, the guage would get to 100 before the fans kicked in which made me very nervous. [snip].

My 88 (with all new cooling system parts including 40% larger aluminum radiator July 2011) works very close to factory spec - runs about 80F normally (slightly cooler than the factory spec of 82F thermostat) and the fans kick in around 92F (again, factory spec).

In hot San Jose, CA, it never gets to 100F because of the 92F kick in. Even when crawling in San Francisco, CA on a rare hot day. Is my 88 simply different?

[Type82]

My car has an 'Overide Switch'
if I'm sitting at a 'Stop Light' or stop amd go traffic on hot day's it helps.


When you have an overheating problem please don't think this is a 'Quick Cure" to the problem... Investigate the problem which is most likely a plugged radiator core or other problems.