Fan Conversion and Electrical Question

[Ken K]

Their are two types of cooling fan motors. Those with traditional series wound fields are larger in size and can pull 20-30 amps. The "Flat" type motors use a round magnet (Toroidal) use 10 -15 amps. Newer fan blades with an "S" shape are very quite and move from 200 to 500 cfm either in push or pull applications. I do not know what alternator you have, but a GM Trucks in the late 90's come with CS133D as later C/K have AD244. They change be interchange to upgrade to the AD244, one of the toughest on the market. The website "Alternatorman" has a voltage regulator D200SEL that converts a junk yard find to a one wire alternator. To increase the life of the AD244, look at his D897SE kit, that uses 80 amp diodes, copper diode plate, brushes and previous regulator. Outputs of 250 amps or higher can be achieved with the AD244 if needed, but heat kills the diodes and engines both. Find a simple screw-in one wire temp switch, get it as close to the engine side of the thermostat and use it to ground a fused relay to control each fan, with common switch. To be on the cheep, you can install a toggle switch to control one or both on those days you need it. Note: Many digital amp clamps are sold for under $30 that are extremely accurate as compared to my Fluke toys and will give you the current used over all, or in each circuit. If you have a lot of electrical toys other than stock, check each circuit to ensure the correct fuse is selected for harness protection. Fuse pop due to the heat generated from over amperage from it's rating. Time v Amps for fuse operation as cold copper coils may pull 22 amps when first turned on, but operate continuously at 15 amps heated up while running.

 

[ThAt_blueZ]

A lot of fellas on here (myself included) are running AD style NBS alternators with more output than the CS style factory alternators. Also, there are better factory GM clutch fans that bolt on & fit in the GMT400 factory shroud like they're meant to be there. I swapped from the metal 5 blade fan to a plastic fan from an S10 and immediately noticed less fan howl, cooler engine temp, and cooler AC.

Now isn’t the nbs alternators just a quick swap on application or is there some tinkering to do get them to fit and belt size was just wondering cause I’m thinking about doing the nbs alternator and wanted some insight before I just went ahead and threw it together and then had issues later.

 

[slowburb]

It's appropriate to replace cables with those of a heavier gauge. I have the same belt on with mine.

 

[ThAt_blueZ]

It's appropriate to replace cables with those of a heavier gauge. I have the same belt on with mine.

Alright 10-4 thanks man

 

[RussKincaid]

I built an E-fan system for mine, first tried out the budget stuff from Hayes I think and ended up almost blowing my engine when it failed. Now I have it pretty nailed down, I used a CS 144 from an Olds for the Alternator. I did have to Fabricate a Bracket, but my truck is TBI, and Vortecs have a different setup. I cut my old shroud and fitted it with dual e-fans from a Cadillac LT-1 Eldorado, since it was designed for a similar engine. I had to cover some holes with Sheet plastic to ensure all the air went through the fans.
I chipped the computer and wrote a program for fan control, but you probably don't have that option, so I would advise to run Dual fans with one fan per relay and coolant switch, then add an override switch in the cab in case something unexpected happens. Keep a couple extra relays in the glove box for insurance, and don't forget to wire in control for the A/C compressor clutch, when it turns on you want your fans on as well.
My setup was pretty budget friendly as most of it came out of the JY but it works flawlessly, and I spent a pretty good bit of time on making it as reliable as the rest of my truck is.
+1 on bigger cables BTW I did that too.
Point being it can be done on a budget, but to create a system as reliable as a factory setup does require thought and patience. If you need some specifics ask.

 

[gmachinz]

I use the CS144D 140A alternators also-here is a pic of the adapter bracket I use on GM serpentine conversion setups. Those alternators are extremely durable and stable for high amp drawing electrical systems.

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[gmachinz]

I also build my own 3-speed resistor control fan harnesses for extreme duty OEM fans also.

This harness allows you to control the fan voltage so it isnt such a hard hit to the charging system.

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[RussKincaid]

That's a nice looking kit! how does the resistor work, is it IC controlled or turns on certain relays at different temps integrally?

 

[gmachinz]

I experimented with a lot of various types of fixed stainless resistor boards and basically came up with one that provided 3 smooth speeds, when used with a properly wired relay bank, one coil resistor basically "drops out" and since electricity follows path of least resistance, voltage goes up. So for example when wired for low speed, voltage must push through all 3 sets of coils, medium speed pushes through just 2 coils and med/hi pushes through 1 coil. Then I add a high speed bypass for AC applications so all 3 coils are bypassed. Its a very mechanical approach to controlling fan speeds and is overkill on anything other than extreme duty OEM fans which typically pull big amperage numbers. Without using sensitive (ie failure prone) PWM fan controllers or PCM controllers I dont think theres anything better-and its all replaceable parts too at most parts stores. Relays are rated at 250,000 switching cycles so their lifespan is incredibly long as well-at least the ones I use are.