86 12 Brutus Posted July 19, 2020 Author Share Posted July 19, 2020 My converted truck doesnt blow that cold. I hope to get it to there by making corrections. First off my '82 is dealer AC, it has the non AC 5 bladed flex fan which I have a 7 bladed flex fan which was a option for AC equipped trucks aside from a 6 bladed clutch fan. I also think I might have a problem with the old thermostatic switch for the cycling of my AC system, it cycles off at around 45* but will blow 58* out the vent all day long at 100* ambient air temp. I am going to swap my thermostatic switch out for one I found on ebay that has an identical plug to mine but is for a 65 mustang that has a AC cutout of 25* and a cut in of 32*. I hope this coupled with the correct bladed and sized fan should help my AC out. if not the next step for me is to junk the tiny dealer condenser and install a full width condenser that is made for 134A. I have to double check but I believe mine is also an expansion valve system since there is no accumulator and just a receiver drier. The thermostatic switch is to allow you to control the temp out of the dash as there is no blend door for the AC. I am not sure there is a upgrade for the expansion valve, the one on my '78 Mercury I converted to 134a would get the inside of the car down into the 30`s and would actually ice up the top of the cast iron compressor. we have had trouble with the blend door on this truck and some lincolns we had out of the 80's. they are cheap plastic. take the ploon out and do a repair on the blend door with small hinges and washers from the hardware store. it will work like new again and never break Link to comment Share on other sites More sharing options...
86 12 Brutus Posted July 19, 2020 Author Share Posted July 19, 2020 we have had trouble with the blend door on this truck and some lincolns we had out of the 80's. they are cheap plastic. take the ploon out and do a repair on the blend door with small hinges and washers from the hardware store. it will work like new again and never break ill take some pics later today to show you what we did to the blend door Link to comment Share on other sites More sharing options...
86 12 Brutus Posted July 19, 2020 Author Share Posted July 19, 2020 ill take some pics later today to show you what we did to the blend door I am assuming that all of your conversions are with 80% 134a. I've done quite a few and blew some compressor seals over charging. 134a has a much higher head preasure then r12. Link to comment Share on other sites More sharing options...
86 12 Brutus Posted July 19, 2020 Author Share Posted July 19, 2020 I am assuming that all of your conversions are with 80% 134a. I've done quite a few and blew some compressor seals over charging. 134a has a much higher head preasure then r12. Steve, every single thing in the ac system is brand new condenser, evap, compressor, hoses, receiver drier, fixed orifice tube, cycling switch, expansion valve, even the blower motor Link to comment Share on other sites More sharing options...
FuzzFace2 Posted July 19, 2020 Share Posted July 19, 2020 The other thing I forgot to mention is that you have to change the clutch pressure switch on the receiver/ dryer to one that is for R134 as the pressures run different then they do for R12. That makes a big difference in the way the AC performs. Not meaning to sound mean or anything, but it sounds like someone did dident do a complete job when your system was converted to R134. Steve, what switch (part number) are you using for 134a? I looked up the switch for my truck, 81 factory AC, and for a 85 and both were for R12. If I was to get one say for a mid 90's truck, should be 134a by then, I don't know if the plug would be the same as mine. I also seen a post that mine might be adjustable, need to look when back in the garage, and just a vary little turn is needed. Factory AC 300 / 4.9 trucks came with fan shrouds the non-AC trucks only had a fan guard on the top so you did not get eaten by the fan. Because my truck was a mix of parts when I got it has I think has a 5 blade fixed fan. I had to come up with the shroud and it made a big difference on the amount of air pulled thru the grille. BTW the radiator supports are for AC or non-AC trucks, I have an AC one. The new condensers do not bolt in. You have to space it forward so even less room between it and the grille. From what others have posted over the years on 134a change over I don't see any issues not having a pusher fan out front as long as you have a good fan & shroud. Still working on getting my AC system together and working. I am this close .......... LOL Dave ---- Link to comment Share on other sites More sharing options...
86 12 Brutus Posted July 19, 2020 Author Share Posted July 19, 2020 I am still using the stock clutch fan. If it is not coming on when the pressure on the high side this between 250 and 300 lbs, it needs to be replaced any ways. What alternator do you have? If it still has the stock 40 amp alt, you might want to swap it out for a bigger one first. The reason I am saying that is that the smaller alternators dont put out much if any at an idle, say sitting at a traffic light in the heat of the day. When you add the load of the AC blower motor, an aux fan for the AC system, and what ever else you have on, you can kill a battery quick. Is the AC factory or add on. The reason I am asking is there is a different fan shroud for the trucks with factory air and without air. The fan shroud makes a big difference with the amount of air pulled through radiator and AC condenser which is in front of the radiator. Just some thoughts. Dont take what I say as gospel. Just some thoughts to help out if I can. Dont quote me on this yet, i am waiting to hear from my ac guy. The clutch preasure switch would say is for r12 systems. When you fill a 134a system you only fill to 80% which gives you the same preasure. Do not take my word on the switch yet, ill post as soon as i find out. I need this info as well. Filling the system to 80% is absolutely right though. this part i know first hand. Link to comment Share on other sites More sharing options...
86 12 Brutus Posted July 19, 2020 Author Share Posted July 19, 2020 Dont quote me on this yet, i am waiting to hear from my ac guy. The clutch preasure switch would say is for r12 systems. When you fill a 134a system you only fill to 80% which gives you the same preasure. Do not take my word on the switch yet, ill post as soon as i find out. I need this info as well. Filling the system to 80% is absolutely right though. this part i know first hand. I am also having issues with the expansion valve. everything i find is for dealer ac and not factory ac. Link to comment Share on other sites More sharing options...
Gary Lewis Posted July 19, 2020 Share Posted July 19, 2020 I am also having issues with the expansion valve. everything i find is for dealer ac and not factory ac. Have you found the page at Documentation/HVAC/HVAC Systems? It has the section from the 1985 factory shop manual on factory-installed A/C systems. Link to comment Share on other sites More sharing options...
86 12 Brutus Posted July 19, 2020 Author Share Posted July 19, 2020 Have you found the page at Documentation/HVAC/HVAC Systems? It has the section from the 1985 factory shop manual on factory-installed A/C systems. I have the whole set of books on the truck, all 5 of them. they come in handy If anybody needs anything i will be happy to send copies of whatever you need Link to comment Share on other sites More sharing options...
86 12 Brutus Posted July 19, 2020 Author Share Posted July 19, 2020 I have the whole set of books on the truck, all 5 of them. they come in handy If anybody needs anything i will be happy to send copies of whatever you need As far as it goes for us right now. I'm just asking the questions that i have some doubts about. We haven't started installing anything yet. All the ductwork is done and complete. Once the dash goes back in we are going to get started on it. Just want to get my ducks in a row if you know what i mean Link to comment Share on other sites More sharing options...
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