You didn't mention what kind of vehicle you're talking about, but here's a
guess.

Probably a failing A/C clutch. Many times they will work at first, then after
cycling off, fail to re-engage when cycled back on. A weak clutch field, too
large of an air gap or just plain worn out.

Next time it's in fail mode, give the compressor a tap near the clutch. It may
get the clutch to engage. If it does, you've found the problem. Another way
would be to unplug the clutch field and check for power while in fail mode.
Just watch your fingers around the belt and other moving parts. 1st test is the
easiest, but not always conclusive if it fails to re-engage.



In message <20040805000720.10918.00001979@mb-m25.aol.com>, "Handywired" wrote:

>Works fine for 5 or 10 minutes, then stops working. I had it checked and the
>guy said it has the correct amount of refridgerant. He could not get it to
>fail at his place though. Here's a couple more specifics:
>
>when it is in it's failure mode, IE engine is running and the dash control is
>set for A/C and it blew cold and then stopped working, if I pop the connector
>off the high pressure switch the switch shows continuity. If I pop the
>connector of the low pressure switch, same thing. Does this tell anyone
>anything?
>
>Generally speaking the vehicle needs to sit a while before the A/C will work
>again. Just leaving the dash sontrols set to A/C does not work; you can drive
>for an hour and still no A/C.
>
>ANy ideas? WHat else can I check?
>
>-jeff

 

You didn't mention what kind of vehicle you're talking about, but here's a
guess.

Probably a failing A/C clutch. Many times they will work at first, then after
cycling off, fail to re-engage when cycled back on. A weak clutch field, too
large of an air gap or just plain worn out.

Next time it's in fail mode, give the compressor a tap near the clutch. It may
get the clutch to engage. If it does, you've found the problem. Another way
would be to unplug the clutch field and check for power while in fail mode.
Just watch your fingers around the belt and other moving parts. 1st test is the
easiest, but not always conclusive if it fails to re-engage.



In message <20040805000720.10918.00001979@mb-m25.aol.com>, "Handywired" wrote:

>Works fine for 5 or 10 minutes, then stops working. I had it checked and the
>guy said it has the correct amount of refridgerant. He could not get it to
>fail at his place though. Here's a couple more specifics:
>
>when it is in it's failure mode, IE engine is running and the dash control is
>set for A/C and it blew cold and then stopped working, if I pop the connector
>off the high pressure switch the switch shows continuity. If I pop the
>connector of the low pressure switch, same thing. Does this tell anyone
>anything?
>
>Generally speaking the vehicle needs to sit a while before the A/C will work
>again. Just leaving the dash sontrols set to A/C does not work; you can drive
>for an hour and still no A/C.
>
>ANy ideas? WHat else can I check?
>
>-jeff

 

You didn't mention what kind of vehicle you're talking about, but here's a
guess.

Probably a failing A/C clutch. Many times they will work at first, then after
cycling off, fail to re-engage when cycled back on. A weak clutch field, too
large of an air gap or just plain worn out.

Next time it's in fail mode, give the compressor a tap near the clutch. It may
get the clutch to engage. If it does, you've found the problem. Another way
would be to unplug the clutch field and check for power while in fail mode.
Just watch your fingers around the belt and other moving parts. 1st test is the
easiest, but not always conclusive if it fails to re-engage.



In message <20040805000720.10918.00001979@mb-m25.aol.com>, "Handywired" wrote:

>Works fine for 5 or 10 minutes, then stops working. I had it checked and the
>guy said it has the correct amount of refridgerant. He could not get it to
>fail at his place though. Here's a couple more specifics:
>
>when it is in it's failure mode, IE engine is running and the dash control is
>set for A/C and it blew cold and then stopped working, if I pop the connector
>off the high pressure switch the switch shows continuity. If I pop the
>connector of the low pressure switch, same thing. Does this tell anyone
>anything?
>
>Generally speaking the vehicle needs to sit a while before the A/C will work
>again. Just leaving the dash sontrols set to A/C does not work; you can drive
>for an hour and still no A/C.
>
>ANy ideas? WHat else can I check?
>
>-jeff

 

>
> The computer will shut off the air conditioner if the engine's
>running too hot.

That's interesting... but i don't think it's hot, unless the temp sender is
bad. It stays just under 210 pretty much all the time...

-jeff

 

>
> The computer will shut off the air conditioner if the engine's
>running too hot.

That's interesting... but i don't think it's hot, unless the temp sender is
bad. It stays just under 210 pretty much all the time...

-jeff

 

>
> The computer will shut off the air conditioner if the engine's
>running too hot.

That's interesting... but i don't think it's hot, unless the temp sender is
bad. It stays just under 210 pretty much all the time...

-jeff

 

>
> The computer will shut off the air conditioner if the engine's
>running too hot.

That's interesting... but i don't think it's hot, unless the temp sender is
bad. It stays just under 210 pretty much all the time...

-jeff

 

>You didn't mention what kind of vehicle you're talking about,

Yeah, I realized that about the time i hit "send"... it's a '97 TJ with the
4.0L and a manual tranny. The A/C is factory original, vehicle has 85K miles.

>Probably a failing A/C clutch.

I'll give it a whack, literally! Thanks.

>Another way
>would be to unplug the clutch field and check for >power while in fail mode.

I assume there's a pretty obvious electrical connector at the clutch? I'll
give it a try.

Thanks!!

-jeff

 

>You didn't mention what kind of vehicle you're talking about,

Yeah, I realized that about the time i hit "send"... it's a '97 TJ with the
4.0L and a manual tranny. The A/C is factory original, vehicle has 85K miles.

>Probably a failing A/C clutch.

I'll give it a whack, literally! Thanks.

>Another way
>would be to unplug the clutch field and check for >power while in fail mode.

I assume there's a pretty obvious electrical connector at the clutch? I'll
give it a try.

Thanks!!

-jeff

 

>You didn't mention what kind of vehicle you're talking about,

Yeah, I realized that about the time i hit "send"... it's a '97 TJ with the
4.0L and a manual tranny. The A/C is factory original, vehicle has 85K miles.

>Probably a failing A/C clutch.

I'll give it a whack, literally! Thanks.

>Another way
>would be to unplug the clutch field and check for >power while in fail mode.

I assume there's a pretty obvious electrical connector at the clutch? I'll
give it a try.

Thanks!!

-jeff