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Not working A/C

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jarek_rugby

Not working A/C

i have problem with A/C.
There is no power. I checked on wires. Cluch is working (when i put wires directly from acu).
Where is AC relay in 1986 EFI 5.0 F-150?
I could not find it.

Chicks dig us 'cause we play RUGBY
F 150 1986 302 ci EFI
Pontiac Firebird 400 ci 1973

Gary Lewis

Re: Not working A/C

Administrator

Jarek - I'll bet that your system leaked some of the "freon" over the winter and the pressure is below the cutoff of the Clutch Cycling Pressure Switch, shown circled below. You can find the schematics here: Electrical/EVTM's/1986 EVTM/AC & Heater.

And note that in the upper left corner of Page 143 there's a description of how that switch works. But it isn't unusual at all for these systems to leak a bit over the winter and the pressure be below the cutoff point of the switch. However, add some refrigerant and it'll probably work.

Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

PetesPonies

Re: Not working A/C

Remove the plug from the cycling switch. Jump the terminals. If the compressor comes on, you either have a bad switch, or as Gary said, not enough freon.

Pete's Ponies
Mustang RUSToration & Performance

1982 F100 Flareside
1983 Bronco

jarek_rugby

Re: Not working A/C

I will check, but next question is :
what kind of liquid should be in? r134 or freon?

Chicks dig us 'cause we play RUGBY
F 150 1986 302 ci EFI
Pontiac Firebird 400 ci 1973

Gary Lewis

Re: Not working A/C

Administrator

The truck came with Freon/R12. But since you can no longer buy that surely it has been converted to R134a. Does it have a fitting like the ones below, or any of those shown here: https://nostalgicac.com/fittings-hose-kits/r12-r134a-adapter-charging-port-fittings.html? Those are conversion fittings and that would indicate it has R134a.

Gary, AKA "Gary fellow": Profile

jarek_rugby

Re: Not working A/C

No, it has only for freon.
I read that r134 is based on synthetic oils but freon on mineral and in future r134 could damage seals and compressor.
I read on my import papers that in Germany they suck r12 from my bullnose :(

Chicks dig us 'cause we play RUGBY
F 150 1986 302 ci EFI
Pontiac Firebird 400 ci 1973

Gary Lewis

Re: Not working A/C

Administrator

So they didn't put anything back, just removed the R12? If that's the case then you almost for sure need to get with an A/C company and have them pull a vacuum and fill it with R134a.

Most, if not all, of these trucks are now running R134a, without problems. You really don't have much choice.

Gary, AKA "Gary fellow": Profile

jarek_rugby

Re: Not working A/C

OK, thx.

Chicks dig us 'cause we play RUGBY
F 150 1986 302 ci EFI
Pontiac Firebird 400 ci 1973

85lebaront2

Re: Not working A/C

Administrator

You will need to get a new R134a compatible accumulator (large can on underhood A/C casing) possibly a new orifice tube and new oil to replace the mineral oil in the compressor and rest of the system. Be sure you get the correct oil for the conversion, the normal R134a oil will not mix with the mineral oil and can make a huge mess of the system.

Properly done, it will cool very well, I ran my crew cab with a converted system for a number of years and it cooled quite well unless it sat and heat soaked after stopping, then it took a bit to get cold again, but it did that before being converted so it was more of a design issue than a conversion issue.

Bill AKA "LOBO" Profile

"Getting old is inevitable, growing up is optional" Darth Vader 1986 F350 460 converted to MAF/SEFI, E4OD 12X3 1/2 rear brakes, traction loc 3:55 gear, 160 amp 3G alternator Wife's 2011 Flex Limited Daily Driver 2009 Flex Limited with factory tow package Project car 1986 Chrysler LeBaron convertible 2.2L Turbo II, modified A413

jarek_rugby

Re: Not working A/C

In reply to this post by PetesPonies

I jumped it and compressor comes on :) But now i have to check pressure

Chicks dig us 'cause we play RUGBY
F 150 1986 302 ci EFI
Pontiac Firebird 400 ci 1973

Gary Lewis

Re: Not working A/C

Administrator

If they sucked all the refrigerant out then that explains why it wouldn't come on. And, if so, you'll have no pressure to speak of.

Gary, AKA "Gary fellow": Profile