Not running elec fans on 730...

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Aug 14, 2005 | 06:19 PM

V8Astro Captain

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From: 600 yds out

Car: Bee-Bowdy

Engine: blowd tree-fity

Transmission: sebin hunnerd

Axle/Gears: fo-tins

Not running elec fans on 730...

I'm swapping to a 730 ECM in my '89 Astro which has a mechanical fan with a thermal clutch. Will leaving pins D12 (A/C press fan sw input) and E8 (coolant fan control) blank affect the ECM?

I see at $8019 bit 5 has something to do with a fan input...

?

Aug 14, 2005 | 11:37 PM

JP86SS

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From: Browns Town

Car: 86 Monte SS (730,$8D,G3,AP,4K,S_V4)

Engine: 406 Hyd Roller 236/242

Transmission: 700R4 HomeBrew, 2.4K stall

Axle/Gears: 3:73 Posi, 7.5 Soon to break

I don't run electric fans and it hasn't done anything to mine.
A/C input signals to raise the idle and a few other IAC related items. (I do have that connected cuz I have the A/C)
Fan request input just enables the fan output from what I'm seeing. The bit 5 is to select a normally open or normally closed switch on the input.
Wouldn't worry about it.

Jul 1, 2012 | 11:14 AM

lakeffect2

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From: Rochester,NY

Car: 1993 Caprice wagon "Shammoo"

Engine: tpi'd 406, with P4 ebl EBL 730 ECM

Transmission: custom "4L65" swap.

Axle/Gears: 3.42:1 with posi

Re: Not running elec fans on 730...

Quote:

Originally Posted by JP86SS

I don't run electric fans and it hasn't done anything to mine.
A/C input signals to raise the idle and a few other IAC related items. (I do have that connected cuz I have the A/C) Fan request input just enables the fan output from what I'm seeing. The bit 5 is to select a normally open or normally closed switch on the input.
Wouldn't worry about it.

On the question of "normally open" or closed. I have mechanical fans as well. I've been attempting to test the fan circuit for correct operation before I actually swap. Test LED's hooked up to pins E8 and F8 are on at all times when when in "key on". To energize the circuit properly, do I want bit 5 to be selected with a check mark in the box or left empty ?

Dave Buchholz
Rochester NY