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Rad fan problem
welderman - 29/10/12 at 07:50 PM

Fireblade set up with car radiator and slim fan.

As soon as I turn the ignition on the fan comes on. If I switch the wires around the fan stays on !

What am I doing wrong ?

Help

rusty nuts - 29/10/12 at 08:14 PM

Using a bike engine?? Sorry couldn't resist it. What happens when you disconnect the sensor wires? Do you have e relay for the fan? Is it the correct type of relay?

welderman - 30/10/12 at 08:11 AM

i will try it without sensor at dinner

relay is part of the blade (bec) loom

welderman - 30/10/12 at 08:56 AM

Just done a quick check

Fan runs with sensor unplugged !

ShaunB - 30/10/12 at 09:00 AM

If it's ECU controlled, does the ECU provide the +12v or Earth?

welderman - 30/10/12 at 10:16 AM

quote:
Originally posted by ShaunB
If it's ECU controlled, does the ECU provide the +12v or Earth?



not a clue lol

all i know its running the original fireblade loom with ecu,cdi etc

ShaunB - 30/10/12 at 10:40 AM

OK slightly different question, do both wires to the fan come from the bike loom, or does only 1 wire come from the loom and the other goes straigh to a local earth? I know nothing about the ECU you are using, but know that sometimes it's easier for the ECU to switch the earth side than the power side, i.e. the ECU may be initially providing +12v but switches to earth when it wants the fan on, if you have the other side to earth already then the fan runs when the ECU intends it to be turned off.

Get a multimeter on the fan wires and check what's happening.

Shaun.

ShaunB - 30/10/12 at 10:54 AM

OK, ignore my previous posts, as according to this wiring diagram the ECU isn't involved at all. Basically there is a +12v supply enabled by the ignition switch, and the earth is connected by the temp switch. If the fan is running as soon as you turn on the ignition it sounds like the temp switch is duff.

Does the temp switch have 1 or 2 wires? If 2 then measure the resistance between the contacts, if 1 measure the resistance between the single contact and a earth point. I would expect a high resistance reading when the engine is cold, low resistance when needing the fan.

Shaun.

welderman - 30/10/12 at 01:28 PM

Sender is working I think. It shows temp on dash and as engine warms it goes up

ShaunB - 30/10/12 at 01:39 PM

According to that diagram the temp sensor for the gauge/dash module is seperate from the cooling fan switch. However it was the first Fireblade wiring diagram I found.

welderman - 30/10/12 at 01:43 PM

wonder if the wire to the fan has to go via the sensor, what do you think ?

ShaunB - 30/10/12 at 02:20 PM

The sensor for the dash temp varies it's resistance as the temp increases and the dash sees this as varying voltage and hence can work out the changing temp. The coolant fan switch works in a different way, it is designed connect 2 contacts at a given temp and allow 10A of current to flow to power the fan itself. It's an on-off switch compared to a variable signal.

welderman - 31/10/12 at 09:37 AM

Shaun

thanks for all your help, im just about to order a temp sender unit, apparently that will sort it out. The old blade engine just has the sender working the temp guage/clocks and then i need a temp sensor for the fan, just like you said.

Thanks again

welderman - 4/11/12 at 11:51 PM

Bought one of these. Should be with me Monday. Will get it fitted and try it out