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-   -   A/C Questions before I take it in... (http://www.focusfanatics.com/forum/showthread.php?t=262073)

USARice 07-01-2011 09:07 PM

A/C Questions before I take it in...
 
Long story short I have no A/C. In addition, the blower motor runs for awhile then starts slowing down while making a noise like the blade is hitting something. Leave it off for awhile and it'll start back up. It seems the speed setting has a direct effect on how long it'll blow before dying. The vent position switch is currently disconnected because it stopped turning. I manually switched the vent to "Vent" at the box by gas pedal. The A/C and RECIRC lights both come on as they should. The compressor clutch does not engage at any point, but interestingly enough the cooling fans don't turn on either which they should automatically come on when the A/C is turned on AFAIK. It's like the car doesn't know the A/C has been turned on. I couldn't test switching the relays because the plastic caps came off both the headlight ones but the relays wouldn't budge.

I read through the thread at the top of this forum but I'm wondering if the fan and A/C not working are related and if i'm right that the fans should come on when the A/C is on.

USARice 07-02-2011 02:39 PM

57 Views and nobody knows if the fans are supposed to turn on with the A/C? Ugh.

More info if it helps.

1) I have now either unplugged or swapped out ever single relay, fuse, or diode related to the A/C system. Unplugging any of them had no effect at all in the way the system operated until I got to the inside fuse for the A/C Switch/Instrumentation.

2)The idle does not increase as it should when I turn the A/C on. It should fluctuate in time with turning the A/C on an off and as such does not increase air pressure either with cycling the system. The RECIRC switch does increase air pressure.

3)Turning to Defrost does not engage A/C clutch as it should.

Like I said before, it's like the car doesn't even know the A/C is on. To me that makes it seem like it's not a compressor problem because the other signs of the A/C being on aren't there.

And then there's the whole thing with the blower but I found a guy who'll sell me a blower and new Vent Control Cable for $45 so at least I'll get those parts fixed even though they aren't the source of the problem.

vaboom123 07-02-2011 02:44 PM

It could be possible that the freon is low and it's not letting the compressor kick in. That could be a simple check to evac the system and see how much is in there.

Also I wonder what's up with the blower motor. I'd probably check and make sure nothing worked it's way in there. When I put a cabin filter in my svt (don't have them stock from the factory) you could see right down to the squirrel cage for the blower motor.

USARice 07-02-2011 02:54 PM

Quote:

Originally Posted by vaboom123 (Post 3726757)
It could be possible that the freon is low and it's not letting the compressor kick in. That could be a simple check to evac the system and see how much is in there.

Also I wonder what's up with the blower motor. I'd probably check and make sure nothing worked it's way in there. When I put a cabin filter in my svt (don't have them stock from the factory) you could see right down to the squirrel cage for the blower motor.


Maybe, but wouldn't the idle still kick up as that's a computerized function? And then there's still the issues of the cooling fans not kicking in when the A/C is turned on.

The blower is a matter of it heating up and getting out of round as far as I can tell. It will run a long time on 2, but not so long on 4. That looks easily replaceable so I'll just just do it.

vaboom123 07-02-2011 03:05 PM

Maybe the blower motor resistor is failing when you're running on high for an extended period of time. I've also seen the breaker for the high speed for blower motors get weak and kick out on high speed.

I'm not sure if there's some kind of fail safe that won't let the a/c system kick on if it's low on freon? I'm a heavy duty tech for a living, but just trying to lend a hand. I guess you could check the a/c connections for "dust" build up around them for leaks.

USARice 07-03-2011 07:16 PM

I haven't looked at the connections yet as they're kind of buried and I just had lung surgery a couple weeks ago so I won't be jacking up the car to get in there for a few days or so. Since I have a SAP front bumper now I can see the condenser perfectly clear and I can say it looks fine and the connections on it are clean so if there is a leak it's not there. The A/C worked just fine before the engine got replaced and I watched the guy who put my new engine in evac the system and refill it; he even taught me about what he was doing. We tried it at the shop and it seemed just fine and I didn't really use it much that summer because it was August by that point. That was last summer. Now it doesn't work at all. So yeah, I'm sure there's a leak.

(oh, and the compressor only has like 20k on it)

iroc34 07-03-2011 07:45 PM

No , if the compressor is not kicking on the IAC will not raise the idle. Most likly the freon Is low , and it is not letting the ac pressure switch close. Need to check the pressures in the system. And the blower motor fan hitting some thing. The bearing is shot and the blower needs to be replaced, easy job.

USARice 07-03-2011 08:35 PM

Thanks, that's what I was hoping to hear, that there was a reason the other things weren't happening. I wanted something difinitive in regards to how the parts work together. Well, today was my first pain free day in a couple months, maybe I'll get a gauge and test it later this week. And the fans are also controlled then by the pressure switch or just somehow the system knows the comp isn't kicking in so it's also not kicking in the fans?

AFA blower, yeah, I'm replacing it. I guess bearings are more likely than it warping out of round, eh? :)

Diesel 07-03-2011 09:50 PM

The a/c fan should still be comming on. Your statement of car dosen't know the a/c is on sounds TRUE. On my focus if the selector is in certain positions it won't let my ac run. Bypassing it and manually changing doors might have something to do with this.
need to check for signal at he relay. You can jump the compressor to test the clutch activation

You can use a 90degree pick or screwdriver to pry relay from underneath to check for power or swap in a known good relay

Blower hitting probally bad blower mabey bad cage also, Turning off probally resister/melted resister plug end or just a dead fan motor need to check power and ground at fan when it's not running. I would fix this Piece by piece. And need to take freon pressure should be around 45lbs at low side.

whynotthinkwhynot 07-04-2011 08:03 AM

Quote:

Originally Posted by Diesel (Post 3728125)
And need to take freon pressure should be around 45lbs at low side.

NO: suction (Low) side pressure is dependent on ambient temperature if everything is working correctly. 45 psi might be the correct reading- but IMO I try to get it as low as possible because psi= evaporator temp. The worst that can happen is that your AC will not work at lower temperatures- like when it's 60 outside. Your LP switch is going to cut off the compressor when pressure gets low enough for the evaporator to collect ice which on 134 systems is around 25 psi. I generally look for 30-35 psi when temps are high so I have ice cold air, then if it doesn't work in the fall or spring- add freon sparingly until pressures are high enough for the system to run- and always double check your psi at higher than idle rpm. Another trick to ice cold air is to spray out your condenser periodically- like when you drain your coolant, take the extra hour to remove the radiator, and spray the condenser out from behind to remove bugs and road crud.

That's all beside the point ATM. USARice, your AC problems are most likely all in the dash. The whole AC system is connected so that if one part is not functioning- nothing works. For example, if the blower inside the cabin isn't working, the AC controls aren't going to allow the compressor to engage. That means that the engine cooling fans aren't going to kick on. If I were you, I'd fix the blower and vent selector first. Barring any other problems, that will likely fix your AC for you. The vent selector works on a cable, so follow the cable down and make sure there's not a physical obstruction behind the dash causing your vents from not switching. You can purchase a new cable from Ford if needed. I'll bet it's a physical obstruction though- like a coke bottle cap that got bounced up in a bad spot.

If you get around to getting the AC working, then when it dies due to a leak, we can help you fix it.

BTW, if you have gauges, without the engine or compressor on, the readings will be the same on low and high side. I would expect to see figures about 20-30 psi over ambient temp in F. Don't read too much into those figures unless you read lower than ambient temp- higher is ok for now.


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