AC questions for 85 pup. Need help!

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JoeIsuzu
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Re: AC questions for 85 pup. Need help!

Postby JoeIsuzu » Sat Jun 09, 2018 12:36 pm

You're heading down a difficult path. You should avoid any custom wiring at all costs. Your harness should have the appropriate connectors. You should definitely not put the compressor on a direct, manual switch. It will freeze up the evaporator if it's not connected to the thermoswitch on the core.

Do you have a wiring diagram?

Jack

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puttputtinpup
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Re: AC questions for 85 pup. Need help!

Postby puttputtinpup » Sat Jun 09, 2018 7:14 pm

Im backing out of this thread. I've owned maybe 1 pup with air and it didnt work, so I'll leave the rest of the discussion to those who have more experience. I drove my non-ac pup for about 20yrs and survived
Good luck.

missionkiter
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Re: AC questions for 85 pup. Need help!

Postby missionkiter » Sat Jun 09, 2018 9:11 pm

Ok Jack I will follow your advise. I will keep looking for the right part. No I don't have the wiring diagram. Can you please tell me where I can get it?

Thanks for your help!!!

missionkiter
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Re: AC questions for 85 pup. Need help!

Postby missionkiter » Thu Jun 28, 2018 11:16 am

Jack,

I have all of the parts and I am ready to start the instal. Can you tell me which wire goes to the A/C compressor? There are two empty wire leads close to where the compressor goes. See pic. I am guessing one of these goes to the compressor.

Thanks,
Lorne
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Screen Shot 2018-06-28 at 10.16.08 PM.png

missionkiter
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Re: AC questions for 85 pup. Need help!

Postby missionkiter » Thu Jun 28, 2018 11:24 am

I also need to run a vacuum line to the blower assemble. Do you know the diameter of the vacuum line I need? I think I also need to buy a "T" fitting.

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JoeIsuzu
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Re: AC questions for 85 pup. Need help!

Postby JoeIsuzu » Thu Jun 28, 2018 12:51 pm

I hope someone else can answer these questions. It may be awhile before I can look it up or take pics.

Jack

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Re: AC questions for 85 pup. Need help!

Postby Darby » Thu Jun 28, 2018 6:24 pm

Small bit of info here:
Recirculation flap; Nice to have but not necessary. I've seen a bunch of the early models with aftermarket AC that did not have it and they worked just fine.
My compressor is connected with a bullet connector. The bottom one in your picture.
You're working with a bunch of old parts here and I would guess the AC died before the truck you took it off of. Do you know if the compressor is good?
I would find a way to pressure test the evaporator and expansion valve together before I installed it. When you get all the mechanicals installed, put a good vacuum pump on it for at least an hour and see if it will hold it overnight, preferably 48 hours. If it won't hold vacuum, it won't hold freon. Then you can play with the wiring.
Original owner of a 1993 Isuzu pick up, 2.3 engine, 5 speed with power steering and air conditioning. All original except the radio (still have factory radio).
It's cheaper to fix what you have than to buy someone else's problems.

missionkiter
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Re: AC questions for 85 pup. Need help!

Postby missionkiter » Fri Jun 29, 2018 4:47 pm

I don't know if the compressor works although I bench tested the clutch.

Ok I will do like you say with function testing everything I can before I get in too deep.

Thanks for your help!

zenapup
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Re: AC questions for 85 pup. Need help!

Postby zenapup » Sat Jun 30, 2018 9:50 pm

Two things:
Wiring diagram for 1.9L as that is what mine is (very close for all engines though). Click to enlarge
The wiring connector for the A/C compressor should be taped to the 6 pin engine harness connector going to a coolant temp sensor and the oil pressure sending unit. Should be a bullet connector.

SCAN0104.JPG


Following Darby's advice, I would basically mock up the system outside the truck (connect it all together) and pull a vacuum on it before installing it to the truck. When I did this to mine I found a hole in the low side line from the compressor that was not visible otherwise and it was actually a sizeable leak.
1987 Isuzu P'UP Normal Cab Short Bed 1.9L FED RWD 4-speed manual
1988 Honda Accord LX-i Coupe 2.0L FI 5-speed manual
1995 Suzuki Sidekick JX 4DR 1.6L 5-speed manual
2005 VW Jetta TDI 1.9L Diesel 5-speed manual
2013 Mazda3 iSV 2.0L 5-speed manual

Darby
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Re: AC questions for 85 pup. Need help!

Postby Darby » Sun Jul 01, 2018 1:47 pm

Great idea zenapup. It never occurred to me. I'm always working on a system on the vehicle.
Original owner of a 1993 Isuzu pick up, 2.3 engine, 5 speed with power steering and air conditioning. All original except the radio (still have factory radio).
It's cheaper to fix what you have than to buy someone else's problems.

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JoeIsuzu
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Re: AC questions for 85 pup. Need help!

Postby JoeIsuzu » Sun Jul 01, 2018 3:40 pm

I replaced my original a/c evaporator, condenser, and lines from a late 1st-gen Trooper. I connected everything but the compressor and had it flushed at a local a/c shop, just to remove any old oils and residue ("black death") from a prior compressor failure. They charged me a whole $20. I used a new expansion valve, receiver/dryer, and compressor.

I'm sold on the Trooper condenser--it's thicker than the one used on the P'up. The rest of the Trooper components are identical to those in the P'up.

Jack

missionkiter
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Re: AC questions for 85 pup. Need help!

Postby missionkiter » Tue Jul 03, 2018 4:45 pm

I was able to set the whole system up on the floor and successfully pull a good vacuum. Thanks for suggesting this test.

I have one small issue that has came up. I was able to replace all o-rings with R-134 complaint o-rings except one. There is a 22mm o-ring that is on the compressor that I can't find. I have looked on the internet and auto parts stores and I can't find one. I did find a new black o-ring to replace it. Can anyone tell me if this is a big deal?
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puttputtinpup
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Re: AC questions for 85 pup. Need help!

Postby puttputtinpup » Tue Jul 03, 2018 4:53 pm

I was browsing around Harbor Freight the other day and saw a box with a large assortment of green ac orings. I couldnt tell you exactly what sizes were included, but their website might list the sizes

missionkiter
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Location: San Diego, CA
Isuzu vehicle(s): 83 pup

Re: AC questions for 85 pup. Need help!

Postby missionkiter » Tue Jul 03, 2018 5:47 pm

yea I have searched all around town and all of the large assortment boxes don't have this o-ring.

Darby
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Re: AC questions for 85 pup. Need help!

Postby Darby » Wed Jul 04, 2018 10:16 am

A city the size of San Diego should have a shop that specializes in AC. They should have it or tell you where you can get it.
Original owner of a 1993 Isuzu pick up, 2.3 engine, 5 speed with power steering and air conditioning. All original except the radio (still have factory radio).
It's cheaper to fix what you have than to buy someone else's problems.


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