Can tap into the wire that charges the AC clutch. That's how done with the nelson harness. Think I've read that the AC PCM output doesn't drive enough voltage to pull in a relay.

 

anyone know if these pull more or less air that the flex-a-lites... I have the flex-a-lites and am somewhat happy...they are loud...I would change them out if I knew these were equal or better for air volume...by the way ... did you have to change the radiator too?...is th '05 radiator bigger?
Thanks for all the info.
Damon

 

The FALs':
I ran FAL's fans on my 03 and the OE alt was not up to it as far as heavy brown outs. Like at night with AC on, low beams on, stopped in drive on the brakes, the fans come on and everything dimmed.
So I get a 200 amp from Alterstart and it is no better in this situation. I call them and we spoke about large amperage ALT's no doing as well at low RPM as a lower amperage units especially with today's low RPM idles. I told them I was not happy with the 200 or any ALT that could not hold up at idle. He mentioned a 145 unit they make for H2's that does them very well. We traded out and Walla all is well. I traded the 03 without the alt or FAL's. My brother has the Alterstart 145 in his 04 RCSB and it works just as well.
The 05:
With an OE 145 it does not brown out at all. Even if I work both of the windows at night with AC on, low beams on, stopped in drive on the brakes, fans running, I get no dimming or even a flicker at all. This is with the 05 smart ALT that monitors BATT Temp and voltage and shuts off the ALT when it is not needed.
The relays and such are by the fuse box on the fire wall side. I hear everyone going to a Nelson harness and such but not any reports of duplicating the OE harness of the 05's. This may be worth looking into.
Also, FAL is hard core about hooking the large Positive and Negative wires directly to the battery. I originally had the posi to the junction box and the ground to the frame, but changed it as recommended and it did seem to improve but not as a cure.
As for fuse holders, the new version FAL supplies is a hard plastic unit with screw on terminations. The old rubber cased units with the tethered cover was prone to melt down because of problems in the injection molding process. Plastic got into the connection female spade slots and made for less contact area creating resistance\heat melting them down. Their vendor put the screws to them there. They are actually good folks at FAL.

 

The PCM puts out a negative, it will trigger a relay no problem.

I dont think hooking it up to the AC clutch line will be good, every time the clutch cycles, the fans will cycle.....

 

The OEM fans do seem to work better than the Flex-a-lites.

 

I assumed the AC output from the PCM did the same? If no,it is on all the time so the fan runs 100 % anytime the AC is on?

 

I am pretty sure the AC request will send out a constant ground signal as long as the AC is on. We will see............

 

http://www.pswired.com/misc/pacaudio/05fans.JPG

 

Thanks, I have that info.....

 

Hope so. Problem I see with it is that the fan will run anytime the AC is on. Even when rolling down the highway and there is enough airflow that you wouldn't need it. Same boat I am in. Except cycling with the AC clutch. I only want the AC fan coming on when not moving and the AC condenser is hot enough it needs cooling down. Defeats the purpose of installing the electric fans if the parasitic load to the crank is just passed along to the alternator. Thats why I'm thinking about an adjustable thermostat in the AC condenser core and in series with the AC fan relay. I've not found one that looks like will fit the bill. All this is for highway cruise. The PCM shuts down the the AC circuit at WOT.

I'm considering getting this relay kit from Painless the appears to have some shock absorbing (current limiting) relay...hopefully will take care of the lights dimming when going from 0 to 10000 rpm on the AC fan .
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FAN-THOM ELECTRIC FAN RELAY
#30101 - Designed as inexpensive protection for your electric fan. Provides constant voltage, protects from voltage and amperage spikes and keeps fan from feeding back through the system. An absolute necessity if adding an on/off switch to your electric fan circuit.
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Sorry if getting off topic or thread whoring here. Trying to find a solution controlling these fans without PCM support. I think you will be in same boat.