Need some A/C condenser fan help please
 

Yes, I did a search.

I would like to install some aux fans on my rear deck condenser. Just had the Rennaire system installed on the car, along with a new compressor, kuehl front condenser and pro-cooler. 60 degree vent temps on a 95 degree day. I think I'm going to do some other things to help with the cooling (like tint windows), but I want to try and get my vent temps to around 50 at least.

So - besides looking at the fender coolers from Griffiths, I'm also thinking about adding some electric fans on the condenser. In a search - I found a site for 7.5" puller fans: Size 07.5 pull / Part# 0358 - The Fan Man. My question to this group is - how do I wire them in? I am an electrical system dummy, so please go easy.

Thanks,

Ken

Locate a good 12V source and good Ground, the lid hinge bolt is a good ground.

As far as 12V, maybe the fuse panel, on my 3.2, one of them is not used but has 12V's. You also want to place a switch on it unless you tap off the AC Compressor switched 12v source. This way you don't need to add a switch and use the AC switch in conjunction to the aux fan. But then there may be an Amperage issue. I would at a minimum put a inline fuse or even a relay.

You can pull the wires thru the same hole the defrost system uses on the rear window.

Question, with the famous upgrades, I do not undertand why you are not pulling mid 40's at temps at 90 ambient. I am confused???

What is the high side readings at 90 ambient, is it R134a or R12/R12 type?

Jim

Also most import this Aux Fan will compromise the air flow to your engine.

This is a R134 system. I haven't hooked up my hoses to it to see what the compressor output is.

I'm not too worried about airflow. Given the amount of air that can come in around the grill, and through the bottom, I'm betting the engine can breathe fine. I would like some more air over the condenser.

Maybe I'll wait on this one, and just add another fender condenser from Griffiths.

I hate electrical crap.

Ken

I just did this. I have CIS and had to modify part of the air cleaner to get clearance. Used a relay for the fans and tapped off the clutch wire to pull the relay. I used the three fuse box and tapped of the hot side with an inline fuse. No problem on the right. I was just about to add more freon when my blower motor froze up, so I'm working on that end now. I will post some pictures tomorrow if you want them. It is too dark now. I am beginning to hate all this crap.

I would love to see the pics. Thanks a bunch!

Ken

I know it can get very frustrating. Been there, believe me. I almost had a breaking point when I was under my car for over 11 hours and still towed to the wrench to get it fixed. Not a happy 2 days. My fault, lack of knowledge.

Any who, R134a are you familiar in obtaining a reading with a Gauge/Manifold? ay 90 Degrees ambient 2 inches infront of the front condensor, the level of R134a is critical. Too much and it will not cool properly PERIOD. Acutally less R134a works better some times.

Here is the fill chart: http://www.ackits.com/aacf/ptchart.cfm

You can rent the Manifold from a FLAPS for free.

Simply, hook it up red to Hi side Blue to lo side. High side the hose coming down from the rear condensor. Close the lid,leave it unlatched, maske sure the manifold hoses are not touching any moving parts. Start her and idle at 1750 rpms, note the readings. If too, open hi-side then the center valve of the manifold to remove the R134a. No worries safe for the environment but try your best not to breathe it in, it is suspected cause of testicular cancer.

Jim

P.S. To be clear, I mean air flow to cool the engine down at speed.

Jim - one thing. What does this comment mean:

High side the hose coming down from the rear condensor

thanks,

Ken

Kidasters,

My system is very similar to yours Rennaire w/procooler and desert duty front condensor running 134a and at 95 ambient my vent temps are in the 40s. Are you sure the charge is correct? I agree with DRACO verify that you have correct pressures as a first step.

You may also want to consider adding a fan to the oil cooler in the front fender if you don't have one already. I installed the kit from Elephant Racing on mine and it does make a difference with the AC running.

EDIT: just saw your post in the classifieds for the Sanden 507. Your mechanic is wrong. It absolutely will fit a 3.2 Carrera. That's what I'm running.

Fan Photo
 

http://forums.pelicanparts.com/uploa...1311344717.jpg
http://forums.pelicanparts.com/uploa...1311344767.jpg
http://forums.pelicanparts.com/uploa...1311344799.jpg
These are the pictures,you can see my intake mod (might freak out a purist) the fans and the relay. I think I said that I tapped of the clutch wire to pull the relay and the unfused side of the three fuse block for the power through an inline fuse.

Thanks for that. Mike has installed a bunch of these systems - but maybe he's wrong. Too late now - oh well.

I do have the Elephant Racing oil cooler fan mod, and I like it a lot.

OK - first I will check system pressures (maybe tomorrow), and go from there.

Ededoad, thanks for the pics. Where do the wires on the relay go in relation to the fans and the compressor?

Thanks,

Ken

White to the compressor clutch, black directly above it to ground. Red you can see goes to fan power and the black directly across from it goes to a 12 amp fuse inline with the fans. Notice that I have clamped the rear of the condenser to keep it from draging on the heater hose. I just grounded the fans to the hinge. I used those specialty oil cooler keepers on both sides for the fans but had to move the pax side. I used ordinary tie wraps for that one and it seems more secure.

OK - just measured -

At 2000 rpms -

Low side - 10 psi

High side - 225 psi

ambient air temp - 94 F

Doesn't seem quite right? Low side pressure seems too low.

I got about the same pressure before the fans, high side would build to fast. The system was designed for R12 which will run with lower head pressure. After cleaning the evaporator, plugging some air leaks around the plenum, changing the blower motor and putting on the fans I can get pressures close to the chart supplied by DRACO. I used 16 OZ of R134A. Cools pretty well and I am not stalling the compressor.

Ededoad:

I think you are drawing power from the wrong side of the 3-fuse in the engine compartment. There is nothing on the other side of the fuse. So you should connect there and then it is fused through that panel.

I think that settles it. I'm going to add at least one fan, probably two.

Edeoad, I will be asking you more questions about wiring......

Ken

OK - on the advice of a PM (thanks Michael) I checked temps with my temp gun. I saw 49 degrees with 90 degree ambient temps.

I got the two spal fans from fanman tonight. I Think I'll still try and add them, but it's looking good.

Ken