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It sounds like he's waiting on conversion lines before he really dives into it, but it looks like the plan is to keep the GM compressor, use the Toyota equipment, but bypass the a/c amplifier and just use a relay. Does the system need a pressure switch? And I have no idea how the idle up works on the TBI350's. But I'd like to get that working so it doesn't bog the idle way down.It is just air conditioning. You can out think it! It really is not complicated.
Dyno
See that makes sense to me. Not sure why he'd circumvent that system?Why not use the amplifier. its there the switch feeds through it and the thermister safety feeds through it too. It is all Toyota except for the compressor. And that gets triggered the same as the Toyota compressor.
That makes sense to me! Thanks for sharing. And it works fine without an a/c idle up?I'm no expert but what I did was (1) used a NEW GM compressor that matches my engine (in my case 5.7 vortec) (2) use the OEM condensor and other misc hard parts (3) used a factory GM A/C hose that mates to the compressor, then had the toyota ends put on the other end of the hose where it mates to the toyota parts. Used relay to control a/c compressor (toyota OEM wire triggers relay which then turns the a/c on /off, based on the a/c amplifier. I recall there being some mod or something done to the negative side of the coil (I know I've explained that before , but was not my idea...it does work) I don't recall the details off hand of what I did...as I type this msg, but Ive posted up notes on this before. I have A/C functional on my truck, and run mechanical radiator cooling fan. GM radiator fan (vortec 5.7) and matching GM fan clutch, 4 core OEM type radiator, custom radiator fan shroud. Others helped me and I learned a little here and there so I did not figure all of that out on the first round, so far I've been able to run R12. I would want to use the amplifier. I think there are some notes on using a modified amplifer as well, out on mud also.
That makes sense to me! Thanks for sharing. And it works fine without an a/c idle up?
Shop has hit it's first biggest obstacle with the A/C conversion. They can't find compressor adapters for the TBI350 compressor. Mosley has them for the LS style compressor (Denso 10S17F), but no dice for the 88-95 tbi.
**UPDATE**
We were able to find the adapters, in case anyone else runs into this issue. Vintage Air Compressor Adapter Blocks 34108-VUG
yes it works fine without a/c idle up. I've not gotten around to looking to address that function.
Of course it would work better at idle with the idle up function working.... I have an electric pusher fan on the front of the condenser that I can turn on if needed. I think with the R134 its probably better to have more air flow across the condenser.
When I had my ECM re-programmed I asked for the idle speed to be bumped up from stock to about 800 rpm as I recall, but I don't think that was ever done and I was too busy trying to get it running to screw around with another 2-3 weeks down time. ON truck with manual trans....non issue to increase idle speed RPM within reason...might be a simple option if available. With the 5.7 vortec as I understand the high idle function, the ECM has to get a trigger signal to know that the A/C is on, and therefore to increase the idle speed. One day I'll look into that as my other projects need to get wrapped up some time this decade.
Don't know if new GM A/C hoses are available for 5.7 TBI setup but a real good solution in my view is to modify a GM OEM A/C hose. Leave it stock where it connects to the GM compressor, modify the other ends (take the GM fittings off and add the toyota fittings to the GM hose) works great. I had a hydraulic hose shop do mine.
Thanks for the feedback! I'm less concerned with the idle up, and I do have an H55 manual behind it, so I'll look into bumping the idle up a smidge. He already ordered the adapters, so we'll see how they do. But I do think you're spot on, and using the GM lines would ultimately work better.I see a Delco hose like I'm talking about on the rock auto site. Is this pic not the stock hose that mates to your compressor on TBI 5.7 ?
Just an idea as I mentioned above to modify. the GM hoses are nearly indestructible, there is more than one way to do this. I did not have much luck with the adapters as I initially tried those on my engine with some customView attachment 2417431 hoses....was not satisfied with sealing issues.
Are those the charging ports built into the hoses?I see a Delco hose like I'm talking about on the rock auto site. Is this pic not the stock hose that mates to your compressor on TBI 5.7 ?
Just an idea as I mentioned above to modify. the GM hoses are nearly indestructible, there is more than one way to do this. I did not have much luck with the adapters as I initially tried those on my engine with some customView attachment 2417431 hoses....was not satisfied with sealing issues.
Yes. The GM hose assembly for that era has the high side and low side as part of it.Are those the charging ports built into the hoses?
as noted above, yes. I would have to say that unless you are doing some nice custom setup with the right hoses.....modifing a GM hose is my preferred choice. I did something similar on my 5.7 vortec, I'm using the stock GM OEM a/c compressor hose where it mates to the GM A/c compressor, then I modified the ends to use the toyta relevant fitting on the end to connect to the evap core and the condenser (best choice on a/c hose setup for engine swaps) in my view.Are those the charging ports built into the hoses?
I’m tackling this over the weekend. I have electric fans with a Dakota digital fan controller. The fan controller has an AC idle up slot. I’ve never worked on a AC system but this seems doable.Take the resistor out of the ac amplifier as mentioned in ac amp thread hook factory wire from ac amplifier ro the gm ac compressor and bam that easy dont worry about ac idle up the gm ecm will see a load and idle up some right when the ac is turned on. It will cycle on and off can also adjust the temp cycle on the ac amplifier careful not to adjust it to low or the coil evaporator coil will freeze up.
I have a 2uz conversion and used a trinary to control the electric fan. The trinary threaded into my existing drier which I think was stock style.I’m tackling this over the weekend. I have electric fans with a Dakota digital fan controller. The fan controller has an AC idle up slot. I’ve never worked on a AC system but this seems doable.
Tell me how my plan sounds. Get a drier with trinary switch, remove RPM resistor from stock AC amp, hook up both AC amp and Dakota digital fan control to trinary and run trinary to compressor and a ground? Forgive my layman terms I hope that sounds correct.
Also looking into making custom hoses what are Toyota parts #s that connect hoses to the evap?
Thanks you guys have lots of great info on here