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Topic: blower motor comes on by itself only at low battery (Read 912 times) previous topic - next topic

blower motor comes on by itself only at low battery

while working on my car the past couple weeks, i have allowed the battery to get low several times.

when i turn the key forward and the battery is whats considered not useful,, lets say the industry standard of 10.5vdc,  the blower motor comes on by itself.

whats up with that?

my climate control temp display is not illuminated nor is the system on, but the blower comes on and again, this happens only on critically low battery.
upon getting the car running again, alll is normal ,, i dont have a problem ,,, i just wanted to know if anyone else has noticed this event.

blower motor comes on by itself only at low battery

Reply #3 –
Has to be a mod you did that battery's up the motor on low volts. I am guessing an electronic component powering up a relay. Post the print like Trinom suggested. That should clear the mystery up. Also find a relay that is activated that powers the unit up with a low battery. New cars with weak battery's do very strange things. In the body shop we see this all the time. You would not believe the fascinating things that happen with low battery's and new cars.
I spend money I don't have, To build  cars I don't need, To impress people I don't know

HAVE YOU DRIVEN A FORD LATELY!!

blower motor comes on by itself only at low battery

Reply #5 –
Nevermind. I just re-read your OP, you have got EATC. Like I said, I've heard of early blower speed controllers doing this during low voltage conditions (< 9v). Below 9v, Ford's modules no longer store KAM, and can't process properly if they're supposed to be in on state or off state.  I commonly see newer cars come in with almost dead batteries or bad batteries that don't hold charge, and very often in that condition, they'll barely start and when they do, the cluster will sweep, and they're radio will have to have the clock reset, or a number of other issues like that.

blower motor comes on by itself only at low battery

Reply #6 –
I've read it once again and it does this only with key in run position (is it right?). Then it makes sense, EATC may be the problem. But if it's EATC bug, you won't be probably able to fix it.

blower motor comes on by itself only at low battery

Reply #7 –
Yes, i have EATC.

I did not slave relay mod the blower system, i was helping another member mod "manual Heat" controls  because of the heat and almost melted connector on the rear of the controls.

today i only have the ign sw run and accy slaved to relays.  i suspect that will be the only two i need.
 

blower motor comes on by itself only at low battery

Reply #8 –
Jay i apologize for not making a call to you. The shop is swamped and with the snow we have been so busy with the body shop. Will make sure to ring you Tuesday. Please remind me if i forget thanks tom
I spend money I don't have, To build  cars I don't need, To impress people I don't know

HAVE YOU DRIVEN A FORD LATELY!!