Electrical Jumping AC low pressure switch

JD1964

there is enough sticking out to grab on to
15 Year Member
Jun 28, 2013
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Can I test the compressor clutch by jumping the switch with KOEO or does the engine need to actually be running? All I’m looking to get is a click from the compressor clutch to confirm the electrical circuit.

I’m just trying to make sure I have all my ducks in a row before I bother hooking up the lines and refrigerant.

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This thread might help:

 
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This thread might help:

I found what I needed there. Thank you :)
 
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Good news is I vacuumed the system down for 45 minutes then turned the pump off. 2 1/2 hours later it’s still holding 30 inches vacuum
 
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I don't want to neglect important things on this R134 conversion process. I went ahead and ordered a new drier / low line assembly and a liquid line with orifice tube built in. This system is tight as can be. It's still holding vacuum days later.
 
Vacuum and pressure are two different things.
30" of vacuum is one thing.
250+ psi on the high side is a completely different matter.
I not saying you have a leak, I am just stating that you won't really know until the system is charged and running at pressure/temperature.
I have seen a lot of systems hold vacuum but leak once the system is charged.
If you can, put some dye in the system so that if it does leak, it will be easier to spot.
 
Agree. The system is really designed for pressure. So holding vacuum (while a great sign) doesn’t necessarily mean it won’t leak under pressure.

When I did my AC system, I pulled a vacuum and then filled the system with 100psi of nitrogen and let that sit.
 
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I’ll be changing both the liquid and suction lines. Is it worth while adding any extra insulation to either of these lines to prevent heat transfer in the engine compartment?
 
I’ll be changing both the liquid and suction lines. Is it worth while adding any extra insulation to either of these lines to prevent heat transfer in the engine compartment?


I doubt it will make any significant difference. If anything, i think the insulation is more to prevent chaffing.
 
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I got the lines changed, leak tested via vacuum and charged it up including 27 oz r134 and 4oz ester oil. She’s blowing 50 degrees out the vents idling at 93 ambient temperature. That’s a 43 degree drop and good in my book.

One inquiry I’ll need to follow up on is my e fans. I have the dual Contour setup controlled by DC Current variable speed controller. Their instructions say connect ac trigger to the blue wire on the controller. That triggers the fans to run at 50% whenever the compressor is running. There’s another wire on the controller (red) not being used at the moment and I think it may trigger fans to run at 100%. My question is, should I trigger the fans at 100% or is 50% good enough?

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Start at 50 and see how it goes.

The fans are only good for stop signs, traffic, and parking lots.
OK I'll see how 50% works out. So far I've only idled in the garage. Do you think going down the road at a steady speed will result in even cooler air from the vents?
 
Did the fan come with a wiring diagram? On my 2014 Ford F150, it has that “Sounds like a jet engine” speed, that only comes on at slow speeds on stopped when the outside air temp is approaching Hades. I wonder if the red wire is powered by an ambient temp sensor or the water temp sensor?
 
I'd run the fans higher at idle with the AC on, but that's me. You can certainly do better than 50's at idle and airflow across the condenser may be a reason. That's why it's cooler at sustained cruise. Check for debris and crushed fins and straighten if necessary

I'd expect 40-45 degrees at idle from an R134a system, even at idle.
 
I previously said there was a red trigger wire on the DC Current controller. That is incorrect. There’s a blue one (50%) and a green one (100%).

I checked with Brian at DC Current and verified the following. I can use the blue one on the compressor clutch circuit which will automatically run fans at 50% whenever the compressor clutch is engaged. In addition to that I can run a 12v through an interior mount toggle switch to the green wire. This way I can manually override from 50% to 100% anytime I see fit.
 
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I previously said there was a red trigger wire on the DC Current controller. That is incorrect. There’s a blue one (50%) and a green one (100%).

I checked with Brian at DC Current and verified the following. I can use the blue one on the compressor clutch circuit which will automatically run fans at 50% whenever the compressor clutch is engaged. In addition to that I can run a 12v through an interior mount toggle switch to the green wire. This way I can manually override from 50% to 100% anytime I see fit.

Use a toggle switch with a dim amber light.

I always seem to have a difficult time finding aftermarket automotive switches that aren't trying to be the star of every show when it gets dark. LoL