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cooling fan load idea

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Old 03-20-2011, 07:33 PM
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cooling fan load idea

i installed 4th gen fans on my 1992 rs. i removed the a/c a while ago. when the fans come on it loads the engine down some. since i no longer have a/c i was wondering if i put the positive signal from the fans coming on to the a/c positive signal to the pcm for it to compensate for the extra load.

im using a flexalite controller. i have a positive signal going to a light inside to know when the fans are on.

8746 ecm.
Old 03-21-2011, 10:56 AM
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Re: cooling fan load idea

Can try it and see if it works. There is a table and a set number of steps that can be added when the A/C is active.

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Old 03-21-2011, 06:52 PM
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Re: cooling fan load idea

cool i am going to solder the signal wire in this week to see if it will raise the idle any by itself. i suppose i could get the chip i have reburned or a new one to raise the idle as i want it to. if i were to get about 150 rpm's out of it it would be perfect.
Old 03-22-2011, 08:00 AM
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Re: cooling fan load idea

The fans shouldn't be that big a load IMO... do you have undersized pulleys?

Maybe first check your charging system for proper operation and load test the batterey. If the batterey is weak or has a bad cell this could be why the load on the altenater is high enough to notice the fan load. HTH!
Old 03-22-2011, 05:01 PM
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Re: cooling fan load idea

the reason it is drawing the engine down is cause third gen fans draw like 5 to 10 amps. 4th gen fans turned on draw like 20 to 30 amps.

charging system is perfect as well as the battery. and i have the 6 gauge power wire from the alt to the battery. 14.89 while running. all wiring is correct and new. it is just the amps drawing it down some.

it draws it down 100 rpm's. thats all. tbichips told me it will only raise the idle 25 to 30 rpm's.
Old 03-26-2011, 09:47 AM
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Re: cooling fan load idea

ok took the 6 gauge wire from the battery to the alt. yes it is a 105 amp. put in a good 8 guage wire. i also hooked the a/c request wire to the ecm. now the draw is less and the idle does kick up to make up for it. works great.
Old 03-26-2011, 12:53 PM
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Re: cooling fan load idea

Originally Posted by one92rs
ok took the 6 gauge wire from the battery to the alt. yes it is a 105 amp. put in a good 8 guage wire. i also hooked the a/c request wire to the ecm. now the draw is less and the idle does kick up to make up for it. works great.
Good to hear, it is the IAC bump that really helps out. This is when the A/C input goes active the ECM steps the IAC out to make up for the load.

I wasn't sure if it would actually work as it is dependent upon how the calibration is set up.

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Old 03-26-2011, 08:14 PM
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Re: cooling fan load idea

i was told it was only 25 rpm's. but i think it is about 50. when the fans kick off she runs up about 100 rpm's and then back down.
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