Our AC system SUCKS

I'll get off the can and post screenshot of the circuit

 

BTW, that slight bump at idle rpm is only there to compensate for the drag the compressor puts on the engine when it cycles on. It's not to increase the engine/compressor rpm at idle

 

The probe/adapter goes in the radiator out/engine inlet line. So the fan and controller are actually controlling radiator outlet temps. You want to have it set to approximately 20 degrees below engine thermostat temp.
The a/c part of the circuit is normally tapped into the a/c compressor hot wire so the fan will turn on and off with the compressor. This is independent of the engine cooling needs.

So you have the temperature sensor in the radiator out line which controls radiator outlet temperature and an independent a/c circuit which will come on to a set speed when it gets a signal from the a/c compressor.

It is a solid state unit but NOT microprocessor controlled so I am hoping it works well in the engine compartment. Not my ideal placement but I don't want to route all the wires in the cab and don't have room for much else in there

 

Interesting. I have never messed with those units before but I understand how they would have to be wired up and tapped into for the coolant system and air conditioner system to work properly.

As for the unit being solid state, no moving parts, which is great, but how have the previous units been designed? Was there some moving parts on them or something?

 

No moving parts that I know of but I think the Delta Current Controls (DCC) controller is microprocessor controlled and because of that is more finicky. Some people swear by them and others have had nothing but problems.

Spal had a pwm controller a few years back but it is no longer available. I don't know why but assume it had issues.

Derale has a pwm controller and they have leased the design rights from DCC so they have a similar system. Once again some people say it works great and others have nothing but problems.

I chose to try the Autocoolguy controller and HOPE it works flawless. If not I will be REALLY pissed!

I am also talking with my Toyota buddy to see if there is any way to obtain the TSB kit even though it cant be installed due to the s/c. I just past my 3 year service date on June 24th. Missed it by one week!

 

Oh dude! I would be super upset about that!

Maybe there is still something we can do despite our large intercooler with a pusher fan. Who knows.

 

Now I may be crazy, but I wonder it we could get a long skinny intercooler and mount it toward the bottom, kind of like the transmission cooler you were talking about. Then that would clear up the room for the condenser fan. Might not be able to make it work though.

 

That's sort of reaching.. we may actually lose efficiency in the process of the blower cooling abilities as well.

 

Yeah. I figured the air flow down there would not be as great either.

Taking a completely different turn, I wonder if anyone has ever tried charging their system with industrial R12. When I talked to the guys at killer chiller or maybe it was the Australian company FI inner chillers. When I asked about getting a kit and brought up concerns with the cabin ac suffering. They said to just charge it with industrial R12 and it will cool better than R134.. I think this is what they are taking about. https://m.ebay.com/itm/Enviro-Safe-...947194&hash=item235ae380f1:g:IXYAAOSwx3Va2Sb2

 

Couple of things (not gonna read through all 10 pages but i skimmed some, so forgive me if these have been mentioned *kisses*)

1. Your truck is a dark truck, this is inherently much harder to cool than a lighter color.
2. Fan speed resistor is only used when you select less than full speed. At full speed its direct 12v connection
3. The major issue at hand here is the fact that when stopped and idle the main fan isnt pulling air across the condenser enough and the innercooler in front isnt helping, (just means your main engine cooling system is working well and fan clutch isnt needed to be fully locked).

Solution, Wire in a pusher fan to push some air through the radiator stack, easy wiring, have it fire off a relay when the AC clutch is locked that turns on the pusher fan.

Not Proper solutions include
1. changing refrigerant, The system is already working like it should and will not work better because of this
2. changing evaporator temp sensor resistor to keep AC compressor on longer, this has the potential to freeze moisture / overwork the AC system when the problem is not this.


The AC system in these trucks are decent, but the evaporator core size is the main problem. That stated, i have been out in the middle of the mojave in 115* temps sitting idling with a nice cool cabin temp, But i do not have a supercharger with an innercooler in front.

 

There are other options which can be done for sure.

1. You could get two smaller fans with standard relays and mount them to the intercooler. Then sealing the intercooler to the condenser would help even more.
2. Seal the condenser to the radiator. I have already done this on the sides of my condenser when I installed my CSF radiator.
3. Make the factory fan clutch more powerful. I have done this and it works very well but I'm never satisfied so we will see how my electric fan setup works.

For me, I am all about removing as much airflow restriction from all of our heat exchangers. Those of us with superchargers and auto transmissions have a stack of 4 heat exchangers so my plan since I have a taller radiator is to:

1. Remove factory transmission cooler completely and replace it with the Trucool 4920 which will fit directly below the condenser.
2. Relocate horns to a (to be determined) location away from the heat exchangers.
3. Install powerful electric puller fan which can provide the proper airflow requirements at idle which is difficult for a clutch fan.

 

Do yourself a favor, Dont remove the mechanical clutch fan. Few have gone full electric with proper results, most that have gone full electric, had issues with overheating and gone back to mechanical and never having engine cooling problems. An electric supplemental fan to move air when AC is on will work like a charm, it wont need to be the full size of the condenser.

 

Noted.

 

MVP right here brother. I am going to take a quick gander outside and investigate just how much space I actually do have for a pusher fan.

As for the interior cabin fan, it sort of sounds like the issue is not so much the resistor, (I have never seen the HVAC wiring schematic for our trucks so I wasn't aware how it was rigged) it actually sounds like the motor itself is just not capable of pushing out more air due to a subpar fan motor if the assembly does indeed receive 12v when it is at max setting. So the issue is not the resistor, it's the fan itself.

@Murphinator , it sounds like we need to continue our move forward with investigating whether or not a Tundra, or Avalon HVAC blower fan will fit.

 

@nd4spdbh I am screwed and tapped out to the max on spacing. Nothing further will fit in there. Worse because I use the URD TCAI.

 

Blower definietly gets 12v when on max

See the top right blue box of the first pic in post 183 above https://www.tacomaworld.com/threads/our-ac-system-sucks.556361/page-10#post-18160775

Note, Lo, Hi, M1, M2. Hi goes directly to blower motor and not through the resistor.


Also, even a small fan to push air over a small portion of the condenser would help, theres gotta be some room up there for one, they are pretty thin.

 

Just finished reading the entire thread and didnt see much mentioned about cleaning the evaporator core where the drip tube comes from. After a few years of operation the fins can get loaded up with dust adhered when warm air condenses on the cold fins after you turn it off. Mine has a musty smell when switched from ac to vent only which I've read is an indicator so I'll be looking into either doing the foam cleaner myself or as part of an AC service. Given the OP's arrangement it seems more likely his is a condenser airflow problem but these systems have two sets of heat exchangers and both need to be maintained.

 

I've noticed that since i installed sound deading in the doors and on the back wall, ceiling and floor, that the truck stays cooler longer

 

134A refrigerant sucks it can never get as cold as R12 was.