tcrisp

my problem is my dual fans don't work i have done new relay new sensor i made sure i have correct voltage going to ecm from the cts can my ecm be bad and causing the fan not to come on going crazy trying to get this problem solve help will be great

Tuned Performance

iTrader: (92)

C1 green/white wire of the ecm grounds the fan relay when the cts reaches the desired temp.
If c1 is not grounding you won't have ecm fan control.
This wire is in cavity F of the relay.
D of the relay is hot fan fuse blue wire
E battery fusable link hot red wire
A out to fan pink/blk wire
I'm not sure if there is a dedicated ground for the fan driver but check the Ecm pins A12 , D1,D3 , d6 ( o2 ) ground I think.

RBob

iTrader: (1)

Since neither fan works I doubt it is the ECM. It only controls one fan.

A quick test of the secondary fan is easy. Locate the head temperature switch between cylinders 6 & 8. Disconnect connector and get a jumper.

Do a key-on, engine-off; now ground the pigtail connector to ground. The fan should run, if not then you need to start troubleshooting. Is there power to the relay? Does the relay have +12 volts to the coil? Does the coil ground actually get grounded with the above jumper connected to ground?

Is the relay OK? Are the fan grounds OK?

RBob.

tcrisp

i can get the fan to come on bye insert a paper clips in each of the pigtail for both fan so that sure tell me the the fan are good and ground right and all of my a/c stuff is not on the car will that cause a problem

RBob

iTrader: (1)

I don't know what you are trying to say...

Are you jumping the power from the fusible link power feed to the relay to the feed to the fan, via the relay socket? Is this with both fans?

RBob.

tcrisp

i put the paper clips in this for the fan relay and they came on i don't remember which slot .

Tuned Performance

iTrader: (92)

Great way to backfeed power to the ecm if you dont know what cavities you jumped.
You can do your testing off post #2.

RBob

iTrader: (1)

OK, you are correct , that means that the power to the relay, then on to the fan(s) is good. Plus the grounds for the fans is good. So now either the relay is bad or the signal from the ECM is bad.

Did you jumper two fan relays or just one? If just one and both fans run then the wiring has been modified.

Stock, the ECM only controls the primary fan. With the secondary fan being controlled by the head temperature switch and A/C system pressure switch.

RBob.

keykey

My ECM was bad, and it caused the ECM controlled fan to run sometimes when it was NOT supposed to (KOEO + KOER cold engine), so I'm sure it could also fail the other way around.

Tuned Performance

iTrader: (92)

If just part of the fan 16042368 quad driver is fried without effecting other outputs the fan wouldn't work. The same driver is for the ses so I could see that odd issues could occur.

tcrisp

i check voltage to the ecm and it was good and i got i new coolant temperature sensor . the fan switch i have not change out yet

Tuned Performance

iTrader: (92)

Voltage to the ecm ?
Do you mean the voltage on the yellow wire of the cts ?
At normal operating temperature this will be about 1.6v.
Iirc if the cts is unplugged koeo the yellow wire would measure 5v reference.
Grounding c1 has no primary fan control ?

tcrisp

I unplug the connecter from the cts on turn key on did not start car took my meter wire and touch the yellow wire and ground the other wire from the meter to the car and got 5 volts and that telling me I have signal to the ecm is this the correct info on checking the ecm signal

RBob

iTrader: (1)

Quoting my own post, it could also be that the relay coil isn't getting +12 v ign switched. There is a fuse for this feed, not sure what it is labeled.

RBob.

tcrisp

where is the relay coil at

Tuned Performance

iTrader: (92)

In the relay !

tcrisp

i know what your talking about now. the relay or brand new i know you can get bad one i did buy them from auto zone

Tuned Performance

iTrader: (92)

Tan/white wire at the relay