VH45 ecu question

[RichZilla]

My VH45 came with a clutch fan, but I'm using an electric fan. The wiring diagram shows an output from the ECU for a fan relay. However there's no pin in my ECU plug for this. Is it likely that the output would still be programmed into the ECU?

Can I just put a pin in there and connect it to a relay?

[elwesso]

What ECU are you using and what wiring diagram are you looking at?

The early VH45s had fans controlled outside of the ECUs, the 94s fan was controlled by the ECU. one of the few differences between early and 94+ ECU.

[RichZilla]

I'm using the '94 diagrams because they are the closest match to my loom. Don't know what year the ECU is. I guess I'll pull the lid off and see if that pin goes anywhere on the board.

[elwesso]

can you give me the number on top fo the ECU? Does your CAS have the side mount connector or the top mount connector?

I have an early FSM that I can take a pic for you.

[RichZilla]

I'd have to get back to you about both of those questions. I'll pull the lid off and see if that pin goes to a transistor or driver. Then I'll measure voltage with the engine running. That'll answer my question. I was just hoping somebody knew.

When I work it out, I'll post up my ECU number and my results. I'd much prefer to have the ECU control the fan. I don't like those adjustable temp switches that you put in the radiator.

[qsiguy]

Doubt that output will have voltage on it unless the ECU is ordering the fan to turn on because of high temps. Don't expect an output as soon as you start the motor.

Just post the ECU part number and we can look up what year it's from and some of the options the car had.

[RichZilla]

According to the FSM, there is a small voltage at the ECU with ignition on, but no fans operating. Still haven't got around to looking at the ECU. So many other things to do at the moment.