Thread: Relays .. One for the Auto spark in us

An agricultural fix would be to only use two relays one for low speed fan feed by ac clutch and one for high speed fan feed by your temp feed same result but much simpler

Originally Posted by THE BOOGER

An agricultural fix would be to only use two relays one for low speed fan feed by ac clutch and one for high speed fan feed by your temp feed same result but much simpler

Good suggestion ... BUT ... I can't alter the 3 Ford relay setup ... as that is how Ford have set them up for the fans ... My diagram (Slightly) glosses over how they work .... as I think the low side feed relay, has a resisted feed wire ... but shows it's basic functions of how Ford set them up



I can only alter the AC & Temp input switch relays

Mike

I was under the impression that they ran the fans in series for low speed and parrallel for high speed... but I could be wrong.

The description of what is happening and the diagram don't gell for me.

That middle relay (blue one below the three red ones); all it is doing is making the circuit go into a don't care what the aircon switch is doing state. Once the Temp Switch powers that middle relay up you can turn the aircon switch off and the low speed feed of the fans will still be energised.

I suspect that the fans have two windings and to run at high speed they need both the low speed and the second windings to be energised to produce high speed. That middle relay just means that when you have hit the temp switch threshold it does not matter if you turn the aircon switch off the fans will run at high speed until the temp switch senses the temp to be below the ON threshold.

I can't see how the middle relay would latch ON, once the temp switch goes to OFF the middle relay should deenergise.

There must be some other wiring that is not shown on the diagram to explain the described behaviour.

Originally Posted by slug_burner

I can't see how the middle relay would latch ON, once the temp switch goes to OFF the middle relay should deenergise.

Neither can I .... but here we are


Mike

try asking on Australian Ford Forums - powered by vBulletin , theres been more than a few people on there who have put the EF/EL/AU thermo fans into earlier falcons

Originally Posted by mike 90 RR

I have put a multi meter on it (bridging relay) and found that it spiked 3v with a drop to 1/2 volt constantly ... (measured on the input + line feed of the temp input wire) ... Basically the coil is "making volts" because of the current of volts passing thru it

IS there a more agricultural style relay I can use?? ... as this one is too trigger happy for this application

I can't work out how it's making volts .... IE energising ...

I recon it could all be solved with a more agricultural style relay ... So what kind of relay would suit???

Originally Posted by BigJon

I was under the impression that they ran the fans in series for low speed and parrallel for high speed... but I could be wrong.

I recon your right

Originally Posted by Sprint

try asking on Australian Ford Forums - powered by vBulletin , theres been more than a few people on there who have put the EF/EL/AU thermo fans into earlier falcons

I was hoping that it wasn't gonna be that complicated

Mike

It might be the time of day, but I think if you take out the blue relay in the middle it will work?
Can I ask why you have the aircon relay operating another relay, would it not be better to operate the low directly from the aircon relay?
I think the coil in the centre relay is providing enough voltage from the low relay output to keep the other relays energised.
I still can't see why the centre blue relay is there.
Fraser