HVAC binary or trinary switch?

[FE3X CLONE]

Here's the deal. I have an after market A/C setup that I am hooking up to my 455. All the wiring diagrams call for a trinary switch if your using electric fans, otherwise you use a binary switch. The trinary switch engages the electric fan(s) if the system pressure gets too high.

From the get go I planned on installing a trinary switch since I have electric fans but do I really need to?

My Accel Thruster EFI controls both my electric fans as well as the WOT A/C clutch cut out. It is also setup to turn the fans on anytime the A/C is turned on. If this is the case, then wouldn't I be okay with just a binary switch in the A/C system?

Thanks,

 

[tc1959]

It sounds like it would work OK. As long as the fans are running while the AC is commanded on you should never see a high pressure situation.
The trinary switch would be needed if you weren't using a controller module. I am assuming that the Accel EFI controller is set up to trigger a single fan or a set of fan relays.

 

[FE3X CLONE]

Yep. The Accel ECM can be setup to control two fans individually through a pair of relays. You can have each fan set to different operating temps so that there is less draw on the electrical system by only running what is actually needed to keep the engine cool.

My other thought was to wire the trinary switch into the secondary fan.

 

[tc1959]

Yep. The Accel ECM can be setup to control two fans individually through a pair of relays. You can have each fan set to different operating temps so that there is less draw on the electrical system by only running what is actually needed to keep the engine cool.

My other thought was to wire the trinary switch into the secondary fan.

That should be Ok, that way both fans will run when AC is on which is ideal to keep AC head pressures in line.
Sounds like it's gonna be an awesome set up.

(something I learned by trial and error get a alternator that will make about 100 amps loaded at idle if necessary..)

 

[FE3X CLONE]

(something I learned by trial and error get a alternator that will make about 100 amps loaded at idle if necessary..)

I currently have a 105 amp delco alternator from a '95 S-10 that I will be using. The plan is to see how it holds up and if need be, upgrade it to something like 140amps or so.

 

[tc1959]

(something I learned by trial and error get a alternator that will make about 100 amps loaded at idle if necessary..)

I currently have a 105 amp delco alternator from a '95 S-10 that I will be using. The plan is to see how it holds up and if need be, upgrade it to something like 140amps or so.

I am running a 105 amp CS130 for a 91- 94 Astro van or any Gm car or truck with a serp drive set up .
( you can get any alternator from that era ,you just have to clock the back half to fit what you want to mount it on.)

With the serp belt drive my voltage stays at 13.3 - 13.9 At Idle with the AC on.
While all three fans are running and compressor engaged .
But I am still Running a Q- Jet.


I originally built this set up with a Tuned port intake in mind .
But when a cowl induction hood became available I went that way. ( my uncle hat a 69 chevelle and a 70 camaro) with cowl induction so I went for that , with this car.
I found all the Air cleaner parts also.
The Serp drive just kinda happened. I really like it better than the old v-belts

 

[FE3X CLONE]

Very cool. I have the same serpentine setup from a 4.3l/305/350 out of a truck that I'm adapting to my 455. I just got tired of the stupid v-belts and their brackets.