The_Punisher454

I am having an issue with both fan's coming on all the time.
My fan is running at high speed as soon as the key is on, and only shuts off while flashing a new bin file.
I tried setting word-7 bit-6 both ways, no change.
I have the fan 1 wire on pin E8, and fan 2 on F8. I have no A/C stuff on this car at all. The WUD shows fan1 and fan2 both lit up all the time also.

My fan speed control module is a custom variable speed PWM fan controller. It has 2 ECU inputs which are triggered by the fan1 and fan2 lines being driven low. The variable speed controller uses 10k pullup resistors on these 2 lines to filter false signals. The fan controller works correctly, I think its the settings in the EBL-P4.

Am I using the correct pins, and do any other settings or external inputs influence this?

Thanks
Marvin

RBob

iTrader: (1)

With no A/C and having the ECM control both fans (or low/high), there is no need for the D12 input (fan request). If there is a wire there I would remove it (at least until the fans are working correctly).

Using the E8 and F8 outputs are correct, they are the fan enables (when low).

Change the 10K pull ups to 1K (1/4 W minimum), the quad driver can only sink current, it can not supply current. The drivers have some leakage that the 1K can easily cover.

I would start with the KOEO fan running on high. Until the engine is running the fan should not run, this is built into the ECM firmware. Unless of course A & B are shorted together on the ALDL connector.

Same when flashing, after a short delay the primary fan should run until the flashing is finished. During flashing the ECM is in limp mode, which runs the primary fan output.

RBob.

The_Punisher454

Everything is working good now, Seems I had the AC request polarity set inverted and forgot about it.
And the 1k pullups did the trick just right. The variable speed controller works as expected now as far as the fan1 and fan2 input are concerned.

Question,
Should I use 1k pullups on my external injector driver box I was trying to build? I had 4.7k pullups and something wasnt working right in the car, so we pulled it off and ran the injectors directly from the '730 in the usual way. So we disconnected 2 of the 12 injectors (all squirt into a common plenum above the blower) since I was concerned about running too much current through the stock 730 drivers. Were not quite hitting 80%DC on 10 injectors yet, so the other 2 aren't needed yet...
Anyhow when I get the time to re-visit the external injector driver I'll probably go with 1k on the pullups as well.
Thanks

RBob

iTrader: (1)

Good deal on the fans. I'd use the 1K PU on the injector driver.

RBob.