mldave

On my 86 22 RE truck A/C was added last year.The A/C amp board was non functional and the wrong part # so my friend bypassed that part.The coolest it blows at the vent is 51 degrees on a 95 degree day after running for 20 minutes on the road.What should the temp be?

93YotaGuy

It depends what kind of refrigerant you are running. I would assume it is an R134a system since it was recently put in. If it were R12 it would blow 5 to 10 degrees cooler or so I've heard.

I have an R134a system on my 4x4 and 51 degrees on a 95 degree day seems about right. I would assume that you are getting that reading when it is on full blast right? If so, you might find that at a lower setting it will blow out cooler air. The way the AC system works is by turning the liquid into a gas through the expansion valve which is directly where the hot air comes in. Inside the air box it looks like a "mini-radiator". When you turn it to a lower setting the expansion valve is able to cool down the "mini radiator" or evaporator a little more due to less hot air being blown through which in turn gives you colder air.

The AC temperature can also depend on the amount of cooling that your fan is able to provide at the condenser. When driving down the road or even on the freeway you will notice it will be cooler because the condenser is being cooled more efficiently from the amount of air being passed through it.

4runners with AC came with 2 fans wired in front of the condenser to help cool it down a little more and give you cooler air. You can certainly wire them up and try to make it work. It's tough though with the grill and the limited amount of room you have. I doubt that it will really make that much of a difference but if you are not satisfied it is certainly worth a shot.

Below is a 93 PU FSM for the AC system components in case you wanted to read up a little more on how it all comes together. You'll find that they are similar to what you have.

http://www.ncttora.com/fsm/1993/airconditioning.html

Keep in mind that these are 20+ year old trucks. The AC system isn't the greatest but it certainly does the job especially on a 95 degree day.

Hope this helps!

mldave

93YotaGuy,thanks for the great informative post.Don't have a shady place to park,so that certainly dosen't help.

93YotaGuy

Your welcome!

abecedarian

51 at the vent on 134a is about right. I'd expect around 45-48 with R12.

Did the truck have A/C to begin with, as in already had an evaporator, or was it parts from salvage or a kit added on?

If the former two, the 86 had R12 as the refrigerant; changing the expansion valve to the evaporator could help lower the vent discharge temps.
If the latter, was the kit intended for R134a or R12? If the former, it probably has the different expansion valve but if the latter could probably benefit from changing the expansion valve.

Additionally, some of the 4Runners (such as my '88) had a condenser unit which was known as "supercool" or such, while the trucks and most 4Runners didn't. It basically amounts to a smaller condenser in front of the "standard" one, presumably to help remove a little extra heat from the refrigerant so the air blowing into the cab of the 4Runner was just a little bit colder.
Just a thought- installing that condenser could help drop the vent temps a little even without changing the expansion valve.

mldave

abecedarian,salvaged parts were used as far as I know,and a 134A kit installed.Thanks for the reply.Mostly do in town short trips,so that dosen't help.

abecedarian

Even short trips would benefit from the "supercool" / pre-cooler equipped condenser. It adds some volume to the coolant- I think another 6-8 ounces for some reserve capacity and more area to scrub heat so make the interior cooler even with an R12 evaporator in the pickup.

But, okay. If you're happy, so be it.