Tally TransAm

iTrader: (17)

I think my dual derale 12" fans are drawing too much amperage because i have popped my second 40 amp fan fuse since installing them. they are wired in just like factory. this is the fan LINK

first question is do you think this is because they are on too much as a result of my wideband being wired through my ac pressure switch, or just the fact that they draw too much amperage.

i know two options if it is the former, i will either rewire it through the egr sensor, or install a switch so it only sees ac voltage when im logging it. (i didnt know this at the time but when the ac high pressure switch sees a voltage is kicks the high speed fans on, as a result anytime the wideband is leaner than about 13.0 the high speed fans are on no matter the coolant temp)

but if it is the amperage issue, what are my options? i would like to retain the pcm control of the cooling fans. but the only thing i can think of is to rewire the fans to a thermostat and a separate relay. . .



thanks

OUTLAWZ RACING

iTrader: (9)

Why not program the fans to come on at a set temp through the pcm? I figured just wire them from the factory harness and set the values thru the pcm. You would only need the hot and cold wires from the factory harness.

Tally TransAm

iTrader: (17)

thats how they are wired and set now, but they are on pretty much all the time because if the wideband reads higher than 13.0 (which is during 99% of street driving, WOT is pretty much the only time is drops below) the voltage signal being sent by the wideband through the ac pressure switch triggers the pcm to turn the fans on high. again this is something i found out after i finished the build, i would have never had wired it like this if i had known otherwise

so my concern is i dont want to go through the hassle of rewiring the wideband signal if im going to end up having to re wire the fans anyways.

just kinda thinking out loud on how to fix this and looking for opinions

onfire

iTrader: (17)

What's the amp rating on the dual fans?

I have a baby Derale on a transcooler that draws 5 amps...would not be surprised if two big fan motors exceeded 40amps...should be on their website.

98Camarod

iTrader: (43)

Why not use the trigger wire at the desired temperature for the fans to come on? I don't remember exactly how mines wired, but I know I changed it from power being supplied from the fuse box to supplying it from the battery because I popped two of the relays myself.

I can look and see which pcm wire for my 98 I used, but I'm sure the answer is in the conversion section.

ZLEEPER

iTrader: (24)

My dual pusher fans were creating the same issue. I didn't rewire, I just bought a HO alternator. Probably not the answer you were looking for, but is an alternative option.

1CAMWNDR

iTrader: (21)

Wouldn't it be fairly simple to change the signal wire from the WB from the A/C switch over to the brown wire on the EGR harness??? Then run it for a while and see if the problem persists.

Tally TransAm

iTrader: (17)

i actually just went outside and clipped the wideband signal wire. i have just over 400 more miles of clutch break-in so i can just log stft's since i wont be going WOT anyway, ill still have the dash wideband display

if it doesnt pop again ill redo it through the egr wire, if it does ill redo the fan wiring

ninetres

iTrader: (35)

Go WOT already. Your clutch will be fine unless its a POS.

OUTLAWZ RACING

iTrader: (9)

Ok help me out here.. Why do u have the signal wire for the widband wired to your fans??? I never heard of this.

MUSTANGBRKR02

iTrader: (91)

So he can log it thru HPT without using one of the external hookups.

I have the same fans and mine are running fine.

Tally TransAm

iTrader: (17)

Like said above its so I can log af through hpt. Its not through the fans its through the ac pressure switch since I'm not running ac now. Problem is the voltage through the ac switch triggers the fans on and you can't edit the fans on vs ac pressure table. I disconnected the signal wire so well see what happens now

1CAMWNDR

iTrader: (21)

Very interested to see what happens. What clutch did you get??

OUTLAWZ RACING

iTrader: (9)

Ok sounds better to me know lmao I just dident understand it.

stevieturbo

uprate your wiring, and/or fit a big single

HUNTER02SS

iTrader: (24)

You probably should install a 5 prong relay in between the fans and the fuse. This will eliminate your fuse blowing issue. I had to do this on mine as well. I installed my fans like you did and was pulling to much current. The relay fixed it.

lazylongboarder

iTrader: (2)

+1. I've got two relays on mine. I'm a conversion guy though. Most common Bosch relay's are 30 amp so I just put two.

Another option would be to turn those damn fans off when you don't need em. Run a toggle switch on your low voltage side of the relay and flip em off when your driving cool. My cam doesn't like it when my fans turn on at idle sometimes...

I'd guess I'm running around the same amp draw with dual 14'' fans. Stock Alt

Another option would be to keep your car running cool with an oil cooler, take your fans off the A/C P switch, and have the car run a constant 195* without the assistance of fans like it should. I added a 26x19x2 oil cooler and the Rad fans rarely flip on. When they do, the water and oil temps plummet immediately and behave. Dynamite.

lazylongboarder

iTrader: (2)

Bingo. 10 gauge is plenty.

1CAMWNDR

iTrader: (21)

His fans are not wired to the A/C pressure switch. They are wired stock. His wideband is wired into the 5v A/C presure switch. In the stock wiring when the A/C pressure switch sees a certain voltage the PCM commands the high speed fans to kick-on. In this case; when the AFR is leaner than 13:1, which is all light throttle cruising.

lazylongboarder

iTrader: (2)

[QUOTE=1CAMWNDR;12898257]Yeah, do away with all that.

I'm well aware. I apologize for my typo. I'll speedily fix that asap. I'M SUCH AN IDIOT!!!

Anyways...High speed fans kicking