New owner to a 99 xlt 4.0 sohc with an AC question

[CDblazers]

I have a 99 xlt with the 4.0 sohc that i just purchased with 62000 miles on it I am very happy with this truck and just thought I would post a concern about the ac system to see if any others had recomendations for it. The blower on the interior ac system will decrease speed when accelerating from above 40 or 50 mph doesnt seem to do it from a stand still only highway merging speeds or such. If you really get in the gas it will actually stop all together... any ideas would be appreciated. Thanks all learning alot around here!!

 

[SaleenEXP]

Ford has a switch on the ac that turns it off when your floor it (highway merging or just gunning it. Thats why it will shut off for a sec or starts to blow warmer air. I'm guessing it has to do with either lessening up the stress on the engine when flooring it so it doesn't have to run the compressor.

Better get some flowmasters or magnaflows on your truck ! Than you'll have your air turning off all the time because you won't be able to let off the gas lol!

 

[CDblazers]

thanks for your help... man who would have thought ford would make you think there was a problem

hehhehhehehehe

 

[Robert]

If you are just talking about the compressor cutting off at wide open throttle (WOT) then that is the way it is designed. Anytime you floor it, the compressor will turn off to give you a bit of additional power. What you described though sounds more like a vacuum leak. Do a search. This issue came up twice now in the last couple of months. Basically if your fans stop blowing whenever you get on the gas then you have a vacuum leak somewhere. When there isn't enough vacuum to hold your A/C blend doors in their selected position they default to defrost position. Ford does this so that your defrosters will always work (more important than keeping cool). When your WOT cuts your compressor off, your air will still blow from the vents. When you have a vacuum leak, your air will stop blowing from the vents. That is how you can tell if it is normal or a problem. If it is not your WOT relay, then a search should turn up what was found to fix it.

 

[CDblazers]

Thank you. This is the best site I have come across for usefull explorer info.....

Yes it does not blow air from the vent under acceleration load above 50 mph. stand still is fine but its not even WOT (maybe 30% to 70% throttle) that seems to cause a significant reduction in AC air flow , once you get above 40 mph or so the harder you accell the more it reduces until you let off the gas. When you say search? you mean check for vac leaks in the ac control system?

 

[yob_yeknom]

Search, as in search this site. There's a little row of gray buttons near the top of the screen. One of them is a search button, the most useful tool on this site. It tends to bring up all the info you could ever need.

 

[Robert]

Search Lesson

Search = "A/C Problem"

Find = 252 threads, one of which is "A/C BLOWING THRU DEFROSTER UNDER LOAD" on the first page.

Go to: Dead Link Removed

and look about half way down the thread for what Firedawgy found that caused his problem.