fan always on
 

Hello everyone,

I've megasquirted my N/A miata (come from canada 1990) according to wiki of miataturbo (HR10g code) and modified my board for fan control.
I've used a 2N2222A like described here: datasheet 2N2222A.

My issue is the following: when I switch on my msquirt fan is turning on.
I've modified temperature for
fan on: 78°C
fan off: 75°C

my setup:

http://img399.imageshack.us/img399/774/codebase.jpghttp://img260.imageshack.us/img260/3633/outputs.jpg

I've checked pin of transistor linked to JS0 through a 1K resistor and I always have a 0.5mV. If I have a 0.5mV at Base pin it's logical to have my fan switch on (correct me if I'm wrong!). But I don't understand why I have this voltage since I swith on with my key.

To resume: I don't understand why my fan is always on!!

Thanks for your help!

Romano

It should send a 5 volt signal to switch the fan on; 0.5 mV is an off signal.

Hello Matt,

You said that a 0.5mV from JS0 is an off signal?

ok but if it's an off signal why my fan is on?

That the thing I don't understand.

Romano.

romano, RHD miata?

Hello Braineack,

no it's a LHD. Steering wheel is on the left side of car.
I don't live in UK or JAPAN but in FRANCE!
My miata is a canadian one.

see:
http://img527.imageshack.us/img527/2803/1004961r.jpg

Sounds like your transistor is damaged.

Mine recently started doing this, about 2 months after having my MS out. I've just put it on the back burner for when I pull the MS out again. Figured it may have been a firmware problem. I've not had any problems with warmup till today, 45* out.