Shorting pins A and B results in cooling fans on. Normal?

[gehirin]

Hi all, trying to troubleshoot a crank and no start issue with my '93. I shorted A and B on the ALDL. Turned the key to the RUN/ON position (not the start position) and immediately the cooling fan turned on. I turned the key off since I didn't know if this was normal. Is this what happens when you short A and B when trying to get the flashing codes? Never tried this before.

Thanks for any help.

Tony

 

[Robertwav1]

I did this a few times and I believe my aux fan came on. Never worried about it though cause upon restart, it was off till the car called for it to be on (my car 228°). I just did all my heater hoses on my car, what a fiasco as some parts were wrong, about 5 or 6 hoses. Anyway, living in Florida, never use the heat in the car however in test the hoses on a cool day here, around 62°, turned the heater on and the aux fan turned on as well? I didn't think was normal but it must be since as soon as I turn off the heat, the aux fan stops. I used AUTO and put the increment up to around 80°, maybe because of the auto position it did this.

 

[raymmnz]

The cooling fan will go on when you short A and B then turn on ignition. This had me worried the first time I checked the ALDL. All will be OK when you remove the short key.

 

[DaveP85C4]

Shorting A&B energizes all ECM controlled relays and solenoids except fuel pump. The little B4P boost fan on 84-90 is NOT ECM controlled.