What are your A/C Temps? FZJ80 Looking for A/C help (1 Viewer)

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@Arizona Jeff thanks for posting this.
I’m in the same spot. 97 LX.
Blue fan clutch mod and less than 1000 miles on whole system.

New OEM (or Denso)
Compressor
Condenser
Expansion valve
Filter/Drier
Evaporator
Radiator is new TYC.

Engine runs in the low 190s always.

Not getting cold dash temps at idle or at speed. Only gets to mid 60s to low 70s.

I installed an electric fan but it’s not working right yet.

I need to check pressures too.
May be check the AC amplifier for water damage?
 
May be check the AC amplifier for water damage?
Will check tonight. Also need to check my aux fan wiring. I have a spare a/c amplifier that is clean and dry.
 
What was the air temp at the cowl when those pressures were taken?

Was the ac on outside air or recirc?

What was the temp in the center vent?

Was the hood closed?
I took air temperature away from the vehicle. It was approx. 95 degrees. A/C was on recirc. Air temp was from center vent with both front windows down. Hood was open. Couldn't get lower than about 60-61 degrees. I swear my old unit would get down at least 10 degrees colder under the same conditions but I didn't even think to check it before doing the replacement. I appreciate your feedback!
 
I took air temperature away from the vehicle. It was approx. 95 degrees. A/C was on recirc. Air temp was from center vent with both front windows down. Hood was open. Couldn't get lower than about 60-61 degrees. I swear my old unit would get down at least 10 degrees colder under the same conditions but I didn't even think to check it before doing the replacement. I appreciate your feedback!
I’m the same.
60-61 degrees at vent.
Recirc and 100 degrees ambient.
Aux is running when car is on.
Engine temp 194 from Ultragauge.
Vent Temp is the same with heater valve (firewall under the hood) open or closed. Is that weird?
 
Here’s the inside of my ac amplifier.
Edit: no evidence of water intrusion or damage.
Can’t believe the complexity of this thing.

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I’m the same.
60-61 degrees at vent.
Recirc and 100 degrees ambient.
Aux is running when car is on.
Engine temp 194 from Ultragauge.
Vent Temp is the same with heater valve (firewall under the hood) open or closed. Is that weird?
Is the cabin air temperature sensor connected to the electrical connector and air hose properly?
 
I’m the same.
60-61 degrees at vent.
Recirc and 100 degrees ambient.
Aux is running when car is on.
Engine temp 194 from Ultragauge.
Vent Temp is the same with heater valve (firewall under the hood) open or closed. Is that weird?
I don't know if it's weird but mine is the same. It only varies by a degree or two when I operate the heater valve.
 
I took air temperature away from the vehicle. It was approx. 95 degrees. A/C was on recirc. Air temp was from center vent with both front windows down. Hood was open. Couldn't get lower than about 60-61 degrees. I swear my old unit would get down at least 10 degrees colder under the same conditions but I didn't even think to check it before doing the replacement. I appreciate your feedback!
Based on those pressures, either the system is overcharged, it has too much oil, or you have a lack of airflow across the condensor.

Were all of the components that were not replaced flushed with a proper solvent? I always start fresh every time I replace a component in the system. you will not be able to get the system charged properly if it has too much oil.

Does your radiator have all of the gap sealing foam installed?

My method for charging any 134a vehicle via pressures that does not have a precedure outlined in the FSM:

1. Connect gauges, pull vacuum, leak test for at least 30 mins
2. Fully warm vehicle up, preferrably an 80+ degree day for most accurate charge.
3. Close hood, place one thermometer 3" in front of the condensor for 2-3 minutes to take the amibient air temp
4. Place a thermometer in the center vent, controls on outside air, slider all the way to cold, fan on high speed
5. Place another thermometer in the cowl, out of the sun
6. start charging via low side port, the compressor will kick on and off several times as the low pressure cutoff switch cycles
7. Verify proper high idle speed when compressor is engaged (750-850rpm on an 80 in park)
8. pay close attention to the weight of the can, pressure will drop as it gets cold. you can either submerge the can in hot water OR the professional method, heat it with a torch in 5 second bursts while watching the low side pressure gauge. Stop the torch off when the pressure gauge spikes - dont go past 100psi. You want to make sure you get ALL of the refridgerant out of the can, most people stop when the pressure equalizes. At that point there is still a lot of liquid refridgerant in the can. The can is empty when the low side pressure equalizes with the valve open and the can is at ambient air temp.
9. Once you are getting close to the approx charge weight, close the low side valve and let it sit for 1 minute before checking pressures. Refer to an R134a temp/pressure chart like the one below. The ambient temp is the air temp in front of the condensor for the high side and the temp at the cowl for the low side. The cowl will always be a few degrees warmer due to engine bay heat.

press.jpg


10. Do not rely 100% on pressures, as they vary a lot. Use the cowl and center vent thermometers to determine the temperature split across the evaporator, you should be able to hit a 35-40f split. I watch for the point of diminishing returns, then back the charge off to the peak.
11. Once the split is at peak, close the doors/windows, turn the controls to recirc and let the truck idle and cool off inside for about 10 mins. if it is below 95f ambient and evertything is working properly, the compressor should cycle on and off at idle in park. If it is 95-105f, hold the throttle around 1200rpm and the compressor should cycle. if it is above 105f, hold it at 1500rpm and the compressor should cycle.

Every time I charge a system it takes at least an hour. Make sure to take ambient temp readings as neccesary during that time.
 
Based on those pressures, either the system is overcharged, it has too much oil, or you have a lack of airflow across the condensor.

Were all of the components that were not replaced flushed with a proper solvent? I always start fresh every time I replace a component in the system. you will not be able to get the system charged properly if it has too much oil.

Does your radiator have all of the gap sealing foam installed?

My method for charging any 134a vehicle via pressures that does not have a precedure outlined in the FSM:

1. Connect gauges, pull vacuum, leak test for at least 30 mins
2. Fully warm vehicle up, preferrably an 80+ degree day for most accurate charge.
3. Close hood, place one thermometer 3" in front of the condensor for 2-3 minutes to take the amibient air temp
4. Place a thermometer in the center vent, controls on outside air, slider all the way to cold, fan on high speed
5. Place another thermometer in the cowl, out of the sun
6. start charging via low side port, the compressor will kick on and off several times as the low pressure cutoff switch cycles
7. Verify proper high idle speed when compressor is engaged (750-850rpm on an 80 in park)
8. pay close attention to the weight of the can, pressure will drop as it gets cold. you can either submerge the can in hot water OR the professional method, heat it with a torch in 5 second bursts while watching the low side pressure gauge. Stop the torch off when the pressure gauge spikes - dont go past 100psi. You want to make sure you get ALL of the refridgerant out of the can, most people stop when the pressure equalizes. At that point there is still a lot of liquid refridgerant in the can. The can is empty when the low side pressure equalizes with the valve open and the can is at ambient air temp.
9. Once you are getting close to the approx charge weight, close the low side valve and let it sit for 1 minute before checking pressures. Refer to an R134a temp/pressure chart like the one below. The ambient temp is the air temp in front of the condensor for the high side and the temp at the cowl for the low side. The cowl will always be a few degrees warmer due to engine bay heat.

View attachment 3089305

10. Do not rely 100% on pressures, as they vary a lot. Use the cowl and center vent thermometers to determine the temperature split across the evaporator, you should be able to hit a 35-40f split. I watch for the point of diminishing returns, then back the charge off to the peak.
11. Once the split is at peak, close the doors/windows, turn the controls to recirc and let the truck idle and cool off inside for about 10 mins. if it is below 95f ambient and evertything is working properly, the compressor should cycle on and off at idle in park. If it is 95-105f, hold the throttle around 1200rpm and the compressor should cycle. if it is above 105f, hold it at 1500rpm and the compressor should cycle.

Every time I charge a system it takes at least an hour. Make sure to take ambient temp readings as neccesary during that time.
Sounds like you know what you are doing... Message me if you are interested in checking/fixing my system. I keep thinking it can't be anything too serious since it worked great before the new compressor & dryer. Thanks for the great input!
 
Drove mine around town today. Got the engine temp up to 207 sitting and idling, but usually at 194.
A/c dash temp got to about 57 at its lowest with 10 minute drive at 70mph on freeway.
It stayed mostly right around 60 at the center vents. This is with the system on auto max cold and same when I clicked the fan to high when it kicked off auto. Always recirc.

I ordered some gauges from Amazon so I’ll have some measurements tomorrow.
 
Ok. Ambient 98. Engine 190.
Here are the readings. I have not researched to guess at what they mean. Vent Temps still around 60+/-

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Ok. Ambient 98. Engine 190.
Here are the readings. I have not researched to guess at what they mean. Vent Temps still around 60+/-

View attachment 3090793

View attachment 3090797

View attachment 3090798

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View attachment 3090800

Definitely undercharged.

Follow the directions I posted above to get the charge up, then repost how its doing.

By the way - don’t ever buy anything but pure R134a. Do not put anything that has stop leak or dye in it, they cause nothing but problems. Walmart has it for about $8/can.

Also, purge your charge line before charging.

Send me a PM if you want a hand, I can talk you through it over the phone.
 
Sounds like you know what you are doing... Message me if you are interested in checking/fixing my system. I keep thinking it can't be anything too serious since it worked great before the new compressor & dryer. Thanks for the great input!

I am up in flagstaff, but I will be down there in early september (if you can wait that long). Ill send you a PM
 
Here are my temps.
Starting at 91° outside temp.
First is just a few minutes driving with fresh air
Second is about 10 minutes driving recirculate air
Third and fourth are idling and parked. I think outside air is 95°

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Where would I find this connection? Going wheeling Saturday and I’d sure like some cooler air!
Hi, I believe this connection would be in the driver side wheel well, in the middle section kind of behind radio and up high, it’s tough to get to.
 
Definitely undercharged.

Follow the directions I posted above to get the charge up, then repost how its doing.

By the way - don’t ever buy anything but pure R134a. Do not put anything that has stop leak or dye in it, they cause nothing but problems. Walmart has it for about $8/can.

Also, purge your charge line before charging.

Send me a PM if you want a hand, I can talk you through it over the phone.
Thank you for your input. I took it to a local shop that I trust and they hooked up all the equipment to it, they vacuumed it down and said that it held vacuum and no leaks!
It only had a half a pound of Freon in it so they sucked it out and brought it up to 2 pounds. Also the auxiliary fan (that I so painstakingly installed with a fuse and relay )was blowing air backwards. Somewhere between flipping the fan blade around and changing the wires I messed it up.I’m sure that was not helpful.
 

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