I wondered about my cabin size too. It's a fairly small car, but with lots or room-especially in the back (hatchback). I don't think it's very well insulated either because I can hear everything outside with the windows up.
Is my AC cold enough?
- Thread starter Jonas
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You might have an air flow problem, or the fan isn't working properly. Is the condenser clean with no bent fins? They also fail internally.
I have Yellow Jacket and Master Cool, Robinair is a great choice as well. It pays to pay up a bit more for quality gauges imo.
In the case of the old E-150 I'm pretty sure it matters, especially when it doesn't have rear AC. I can't speak specifically for your vehicle, some have better AC units and are insulated better than others. Years ago many said GM cars had the best heat and AC. I agreed, but I don't want to hi-jack this thread and take it way off topic.
I cleaned the condenser yesterday and it was a bit dirty. I'd say the fins are about 98%. It wasn't as hot yesterday (about 90/partly cloudy) but I was comfortable in my car for the most part. I'll put some gauges on it and report back with the numbers at idle and 2000 RPM if I can find a helper.
If it is now working well I'd be inclined to leave it alone. Each time you put the gauges on the car you can lose a bit of refrigerant. If you weighed the charge, didn't get air in the system switching cans, and you have no leaks I'd be looking elsewhere for the problem, or leave well enough alone if you're comfortable now.
I haven't taken the temp with the fan on low - just 2/3 and high. I'm sure the air is even colder on low as it now has an even longer time to be cooled but you get diminishing returns because the volume being moved is too low. In my experience 2/3's represents a good combination of cold air + enough volume but if it's really hot I still go fan on full for the first few mins - it's not like there's a 30F difference in air temp and so moving and cooling the maximum volume of air still makes sense.
Yes, I'll give it a rest for now and see how it does next heat wave. Cleaning the condenser didn't make it drastically colder, but it seems to cool down faster now. Before, it wouldn't get below 60 until I started driving.
Yeah, med-high is the sweet spot.
No harm in cleaning it a bit more.
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This can actually be normal. But your problem seems to be while you sit still.
Still think it is the condenser fans being too slow or at least part of it.
I wonder if that car has CANBUS so you can see the RPMs of the fans?
I doubt it, but if it does, my cheap scan tool doesn't recognize it. My coolant temps always look good and are a bit cooler with the AC (fan) on. Although, I'm also leaning toward it being a fan relay or the fans themselves because of the drastic temperature difference based on airflow.
I tried to buy all quality AC tools when buying all of this stuff. My Vacuum pump is a Robinair. It's a high CFM one, Model 15600. I think my refrigerant scale is a Master Cool.
It couldn't hurt if you can get access to it without too much trouble. I think you probably have an airflow issue given that while driving the temps are fine but when stopped they go up quite a bit. Whether it's from the fans or something else, I'm not sure.
Go to this website's forum and register and describe your problem. There are some very knowledgable people on there as well as some AC Techs. I learned a ton from this site when I was first learning how to do AC work.
https://www.autoacforum.com/
Thanks for all the help so far.
I'm not sure if this is even a thing, but perhaps there are separate relays for low and high speed fan operation? If the high speed relay is bad, that would explain a lot. I can't find any info on the relays for my car as in which one does what. The three smaller ones (2 blue, one brown) are all labeled fan relays. Is there a way to tell which one(s), if any are bad? Here's a pic: (2 small blue, 1 small brown, near the top)
I'm not sure if this is even a thing, but perhaps there are separate relays for low and high speed fan operation? If the high speed relay is bad, that would explain a lot. I can't find any info on the relays for my car as in which one does what. The three smaller ones (2 blue, one brown) are all labeled fan relays. Is there a way to tell which one(s), if any are bad? Here's a pic: (2 small blue, 1 small brown, near the top)
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are there 2 fans? if so they get switched in series fro low speed and parallel for high speed, that would explain needing 3 relays.
There are two fans. So, if one of the relays was bad, one of the fans wouldn't work at all?
in high speed, yes.
The main relay only, gives power to fan A, one of the blue relays passes this power then to fan B and it continues to an earth. Both fans essentially get half voltage, and 1/4 power.
At high speed, the blue relay provides an earth to the first fan so it gets full voltage and power, and the second blue relay provides 12v to the second fan which has a fixed earth, so also full power.
if the first relay doesn't work, the first fan won't work, if the second doesn't work, the second fan won't work (for hi-speed).
The main relay only, gives power to fan A, one of the blue relays passes this power then to fan B and it continues to an earth. Both fans essentially get half voltage, and 1/4 power.
At high speed, the blue relay provides an earth to the first fan so it gets full voltage and power, and the second blue relay provides 12v to the second fan which has a fixed earth, so also full power.
if the first relay doesn't work, the first fan won't work, if the second doesn't work, the second fan won't work (for hi-speed).
I think I understand. So, if one of the high speed relays were bad, that would cause one of the fans to only operate at low speed? The two blue ones are the high speed relays I assume?
Or, in other words, is it possible a bad fan relay is causing my airflow problem?
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