[sogone]

I'm in the final stages of testing all my electrical equipment on the baleno conversion into sierra. Checking things like connections, making sure their are no fire hazards, all fuses are in good nick and the like. Thought i'd test out the radiator electric fan and make sure it comes on when warm. I got the zook up to about 105 degrees Celsius on a speco gauge whilst idling and lightly revving the motor to bring the heat up.

The electric fan didn't turn on. The fan is wired into a relay that is powered by the baleno ecu stock radiator fan control switch. PJ who I brought the converion from said it worked fine when he pulled the whole lot out and sold it to me. I can turn the fan on by earthing the ecu wire that goes from the ecu to relay, which i presume turns the fan on. What do I need to check to make sure that the temp sender plug is sending the temp back to the ecu and that once it reaches a certain temp that the ecu is sending a signal to the relay to turn the bugger on? I have a multimeter and a test light, however no idea what to look for. Does anybody have any ideas on where to start?

[steak_knife]

Sound's like a sen or plug, please don't earthing ecu wire.....

I also wouldn't trust the speco gauge, cause they are shit....

Take it for a spin....be 100% sure the thermostat is open to.

[sogone]

Isn't that what the ecu does but. Negative switch when the sensor opens? Checked the gauge it's about 2 degrees out with a mercury gauge. Still it should be switching before a 100?

Let it idle for half an hour with 5 minute spurts at 3k rpm. Can't take it for a drive as its still missing a window and other stuff. And unregistered.

[losfer]

the wire that goes back to the ecu is actually earthed by the ecu when the temp sender tells the ecu that the temp is over 96-98 degrees , so i dont see a problem with earthing this wire to test it.

check your connections at the fan relay , they should be something like .. pin 87 constant 12v + , pin 30 to positive side of fan , pin 86 and 85 should be ignition power one side and the wire going back to ecu the other side (to act as a switch when it earths out to close the circuit between 87 and 30)

ohh yeah make sure the other wire from the fan motor is earthed as well ..

[whincup]

i'd be starting with the wire that comes from the ecu to the fan relay, make sure that that is actually getting power first... if it is, then its a fault somewhere between relay and fan. if not, its temp sensor/ecu side of things...

[sogone]

Can isolate the signal from ecu to relay and manually over ride it to turn fan on. Relay checks out, fan is earthed. The sensor reads different resistance from cold and warm. I think it may be ecu. But everything else works fine. :/

[steak_knife]

sogone wrote:

Isn't that what the ecu does but. Negative switch when the sensor opens? Checked the gauge it's about 2 degrees out with a mercury gauge. Still it should be switching before a 100?

Let it idle for half an hour with 5 minute spurts at 3k rpm. Can't take it for a drive as its still missing a window and other stuff. And unregistered.

Yes, but leave the ecu out of it, you have prove the power & relay work, now go look at all your earth's.... ALL of em to do with the eng...

[sogone]

I'll triple check them tomorrow w

[losfer]

the ecu earths the fan relay, if the ecu had a bad earth you wouldnt get spark , and in turn , injector pulse . considering you can get the fan to run by manually earthing the wire to the ecu , you can assume the ect sensor is faulty , or you have a faulty ecu .

[sogone]

I'm leaning towards ecu. Im getting 5 ohm at cold and 35 ohm at 90 degrees Celsius.

Ps. I think it's ohms? Is that what resistance is measured in? Multimeters and I are just starting a wonderful relationship.

[sogone]

From the ect btw.

[jake_]

sogone wrote:

I'm leaning towards ecu. Im getting 5 ohm at cold and 35 ohm at 90 degrees Celsius.

Ps. I think it's ohms? Is that what resistance is measured in? Multimeters and I are just starting a wonderful relationship.

yep, ohms it is. While your going with the multimeter why don't you check continuity between the ECU and Relay, and the ECU and temp sensor

my advice: rule out the ECU last as its unlikely to have such a specific fault and KISS (keep it simple, stupid), much more likely to have bad connection than a bad ECU

[sogone]

How do I do this with a multimeter? Same setting as the resistance test? Will there be continuity between them while it's meant to be switching? How do I check Continuity?

[jake_]

continuity means the wire is "continuos", i.e not broken, between to two points. So your looking for 0 ohms (or close) between the pin on the ECU and the pin on the relay.

This will tell you that the relay is really connected to the ECU.

[whincup]

if your trying to test if the ecu is activating the relay, check the volts (not resistance) from the wire/s coming from the ecu to the relay. should read nothing below a certain temperature, then something like 12v above whatever that certain temperature is.

[JrZook]

whincup wrote:

if your trying to test if the ecu is activating the relay, check the volts (not resistance) from the wire/s coming from the ecu to the relay. should read nothing below a certain temperature, then something like 12v above whatever that certain temperature is.

Other way around. The ECU has a low side transistor switch. The ECU pin should be at 12V when the relay is off and 0V when active. Note you can only measure this with the relay connected.

[sogone]

I will pay airfares for you to come fuck my shit up true and teach me. It all doesn't make sense. The sensor seems good due to resistance testing change once hot. Could it be my ecu?

[Bugsta]

sogone. If you haven't tested continuity of your interconnecting wires, or the voltage output... the change from +12 to 0 at temp, then you can't make that assumption or conclusion. Test the simple things first.

Ok, a little teaching - When using a multimeter to test voltage on a Negative Earth system, (and by this I mean, the negative terminal of the battery is connected to the earth of the vehicle), connect the black probe to a good earth point on the car (not a painted surface). I'd suggest using an aligator clip so you have your hand free. Set the meter to a DC volts range (say 20v - this will vary between meters). Use your red probe to contact your test point. Place your meter in a position you can see it and take the engine through its stages.

[sogone]

Thanks bugsta! As I've said before. Me and my multimeter are just dating. I have no idea of whats going on really. She has many settings. Something upset her. Something's don't. I'll give that a shot tomorrow. What is my test point? The sensor bit that switches once it reach a set celcius?

[Bugsta]

Well, your test points (plural), would be anywhere you need to check for levels. So perhaps eiher side of a connector, on the relay contact and on any other accessible metal conductive points of the path you are in doubt of... until you find something that is not right.

Happy probing

[sogone]

Fixed. New CTS fixed it. Thanks guys!