Revotec fan

[80Sprint]

Just fitting a new revotec fan controller to a Revo fan. The controller is not working. I would send it straight back but the sticker that states void if removed has come off ( too easily on fitting) . Before I have an argument with them I assume it may be the relay. What can I check with a multimeter.? The fan works direct to the battery using the same earth.

[MIG Wielder]

Hi Mike, Revotec kit is normally pretty good, but have a look at the following.
* Can you check for +12V (ish) on both the red wires going to the relay please. ( IGN on or off depending if you need it running when the IGN is OFF ).
* With the IGN off can you check for zero ohms from the black wire on the controller to a good Dolomite earth point.
* Also ( IGN OFF ) please check the resistance between the blue wire from the controller to the red +12V supply. This should measure about 100 ohms. If it doesn't then the relay coil is open circuit.
* With a hot engine can you measure the voltage from the blue wire on the controller to a good Dolomite earth point. It should be +12V again. Then using a small screwdriver turn the adjuster gently from clockwise from one end stop to the other. When you get about 2/3 of the way round on the adjuster the voltage on this blue wire should drop close to 0V.
If there is no change on this voltage the electronic bit is dead. If you see the voltage change on the blue wire the relay is faulty.

HTH,
Tony.

[80Sprint]

Hi Tony
I replaced a kenlowe one for reliability and better fitting. Not sure that plan worked.
There are two red and two blue in to the relay.
Ignition on I have 12v to 3 wires, not the larger blue one to the fan.
Ohms test was 1 if I connected the blue to the large power red but using the smaller red to blue/fan I got 80 ohms.

Not done the controller check yet.

Thanks

[MIG Wielder]

Hi Tony
I replaced a kenlowe one for reliability and better fitting. Not sure that plan worked.

Either fan should still work with the Revotec kit

Do you still have the Kenlow override switch wired in anywhere please ?

There are two red and two blue in to the relay.

This looks fine.

Ignition on I have 12v to 3 wires, not the larger blue one to the fan.

There should be 2 wires to the relay each with +12V on and a link wire between 2 terminals.
At this stage no voltage to the large blue wire is O.K.

Ohms test was 1 if I connected the blue to the large power red but using the smaller red to blue/fan I got 80 ohms.

Do I understand that you measure 1 ohm if you measure between the thick blue wire and the red wire to the fan ?
If so that is roughly correct and is the d.c. resistance of the fan motor.
The 80 ohms resistance looks about right for the relay coil but should be between the small diameter red wire and the thin blue wire. The thin blue wire should only go from the electronic unit to the relay. It should not go to the fan as well.

Not done the controller check yet.

Thanks

Cheers for now,
Tony.

[80Sprint]

It seems to match what you have described Tony. I have not been able to warm it up but does it seem like it’s the sensor in the pipe then that is faulty ?

[80Sprint]

Just an update. All working now.
The new relay was faulty and Revotec replaced it.

[tamtrucks]

thats good news