Driving to New Orleans in my 1994 Accord LX the other day, I found that I had cold air blowing out of my AC when driving on city streets, but once I hit about 70mph, the AC stopped blowing cold air. Only warm air came out of the vents.

When I reached New Orleans, and my speeds dropped back to 35-50mph, cold air started coming out of the vents again.

Searched up and down and can't figure this one out. Any help?

Also, I did notice my antifreeze was pretty low, but otherwise, everything looks in good working shape and levels of all other liquids adequate.

Thanks.

 

if antifreeze is low or too hot the sensor on the front cooling outlet will tell them a/c to shut off. cooling system has to be filled AND AIR FREE!!!!!!!!!!!!!!!!!

 

or maybe low freon levels

 

I assume the line is air free. I paid a shop to do my AC repair about 2-3 months ago, because of that worry, but you know what they say about assuming...

I've filled the antifreeze and will test it on the freeway again to see if any change was made.

 

not sure i ever heard of a situation like this but if it was me i would swap out the expansion valve ... it could be causing a blockage

 

Before throwing parts at an issue I'd want to know what the readings from the high and low side are as well.

 

Normally I would agree in most situations, however considering it appears the ac works for the most part until there is a steady drive(highway speeds), this means the system works but apparently gets blocked off, which in my two cases of ac fixing has been expansion valve fails. Plus the expansion valve is only $15 bucks or so.

 

Maybe something a little more serious - and unexpected. Looked everything over the other day, and found the antifreeze nearly empty.

I think the 1 1/2 hr highway driving caused my engine (with low antifreeze) to start to overheat, and that overpowered any coolant from the ac.

I filled the antifreeze, and made the drive again - granted it was at 6AM instead of noon - but the ac didn't turn hot like before (it also wasn't really cool like before it broke/was fixed - but I'm thinking now that might be a separate issue).

I also noticed that I had to refill the antifreeze 1 week later (returning from vacation). Never had a leak before, and noticed no spots on ground under car, so wondering where the fluid's going...

Think this could be the answer? I'll hopefully look at high/low readings, etc., this weekend.

 

yes a expansion vavle can cause this. i talked to my dad, asked him to ask what he things hes mechanics think about this. my dad came back to me with one solution expansion valve, story is one of my dads co worker at the shop had a 1991 nissan sentra back in the day his a/c would shut off at idle and blow cold, not to cold but cold once the car was going. changed expansion valve and it stared blowing COLDER then it was before and never had that problem. i don't know if he still has the car, i doubt it lol, but i brought you some useful information

 

look for white spots on coolant hoses leaking coolant usually leaves a residue on hoses if the leak is small enough it will pool up and leave like a scale residue

 

the ac and cooling system are completely separate and unrelated .... you need to look for a coolant leak and if none you can do a compression test to check if coolant leaking into the combustion chamber

 

I know they're unrelated, but i figured if low coolant, engine got hot enough to overpower AC. Anyway, probably incorrect thought. I'll look at the hoses and expansion valves. I didn't find anything the other weekend. But, the AC's running (semi)cold since I started keeping the coolant full...

 

make sure vents are on recirculate and not outside air

 

Found my distributor o-ring leaking oil onto the heater hose. That's probably the source of my coolant leak.

Also, I've had no further issues with the A/C since, although it's never been too cool since I had it worked on.

 

I would highly appreciate for telling me what if Battery light keeps off while Ignition Switch is turned on, & when engine is on and ALT fails to charge the Battery?
Battery is brand new, I just seviced the ALT ( Bearing Changed ) Fuse on both under Hood & Dash are intact and seems OK,
Once few days ago it came on and Battery got charged , but again head lights dimmed and battery weakend.
Is there any hidden cause for such defect? the overal check showing all connections & body strap are in place and fixed. could it be caused by the defected Voltage regulator ? What do you think.
Best regards and
Much appreciated and welcome your comments.
_________________
MSP
1991 Accord EXi , F20ZI,