ac on .. car is overheating.

ac on .. car is overheating.

Logged in as: Guest

Users viewing this topic: none

Printable Version

All Forums >> [Tech Section] >> Modular Tech >> ac on .. car is overheating.

Page: [1]

Message

<< Older Topic Newer Topic >>

ac on .. car is overheating. - 8/19/2009 1:53:21 PM

pat_tm

Posts: 1500
Joined: 9/4/2008
From: northampton,pa
Status: offline
Car: 1965 Ford Mustang
1/4 ET: 14.600
1/4 MPH: 92.23

I just got the AC fixed on my '97 after owning it for a year now. It was the low pressure switch. Anyway while driving with the ac turned on the car gets to nearly the red on the "normal" temp gauge.
Without ac running the car will sit around in between the "O" and the "R" in the gauge sweep.
I checked and when I turn the ac on the elec fan on the rad will run and the cooiant level is fine in the tank.

bad thermostat? or is there something with those cars that makes them run too hot with the ac on? the car is stock far as I can tell with the exception of some POS "cold air" thing that was put on by someone else before I got the car.

Post #: 1

RE: ac on .. car is overheating. - 8/19/2009 2:08:10 PM

MKurpicski

Posts: 957
Joined: 7/31/2003
From: Millersville, MD
Status: offline
Car: 1995 Ford Mustang Cobra

Well its not strictly a mod motor issue because I'm having the exact same problem with my 95. I just noticed it earlier this week when I pulled the car out for the first time in about 2 months so subscribing to see if someone can provide any guidance.

mk

_____________________________

On the road again :D Holy chit it feels good to have her running right again.

(in reply to pat_tm)

Post #: 2

RE: ac on .. car is overheating. - 8/19/2009 2:09:49 PM

pat_tm

Posts: 1500
Joined: 9/4/2008
From: northampton,pa
Status: offline
Car: 1965 Ford Mustang
1/4 ET: 14.600
1/4 MPH: 92.23

I'm not sure with this one at all. My blower motor only works when it's on "high" but I'm sure that has nothing to do with it. I know the AC is fully charged and oil well.

(in reply to MKurpicski)

Post #: 3

RE: ac on .. car is overheating. - 8/20/2009 12:19:00 AM

pat_tm

Posts: 1500
Joined: 9/4/2008
From: northampton,pa
Status: offline
Car: 1965 Ford Mustang
1/4 ET: 14.600
1/4 MPH: 92.23

Here's what I've found so far.
I left work today with my scanner on the OBDII port and monitored the coolant temo via the computer. Here's what I found

With the AC off and normal driving home at 5pm the car would run between 91 and 92 degrees C. I saw it climb to 98 then a real fast spike to 128 but then right back down to 93 to 93 with no ac still.

Turned on the AC and it ran arond 106 after 10 minutes with the AC on.it seemed to hover right around 108ish with the ac on high and just normal city driving. the temp gauge on the car's dash was at about the "L' of normal right before the red zone.

I can understand that the AC will create a little more heat but to have the gauge read so much higher seems a bit high to me. keep in mind these are not convereted to F temps so I have to do that tomorrow. I will plug the reader back in tomorrow again in both the morning (usually no ac on) and on the way home again to see what I find out.

(in reply to pat_tm)

Post #: 4

RE: ac on .. car is overheating. - 8/20/2009 9:37:30 AM

turfmn

Posts: 4187
Joined: 7/31/2003
From: Bethel, De
Status: offline
Car: 1992 Ford LX hatchback
1/4 ET: 11.132
1/4 MPH: 127.11

Start with the basics. Is the radiator and condensor clean? Check for bugs, leaves and other junk blocking the airflow. Does anyone know if the fan on a 97 is a two speed fan? 108c converts over to 223F.

_____________________________

"When the people find they can vote themselves money,
that will herald the end of the republic."

(in reply to pat_tm)

Post #: 5

RE: ac on .. car is overheating. - 8/20/2009 9:40:34 AM

pat_tm

Posts: 1500
Joined: 9/4/2008
From: northampton,pa
Status: offline
Car: 1965 Ford Mustang
1/4 ET: 14.600
1/4 MPH: 92.23

a few days ago I blasted through the rad with my water hose when I washed the car. So I'm fairly sure the rad is free of blocks through it. I'm not sure what the normal temp for a stock mod engine is.

(in reply to turfmn)

Post #: 6

RE: ac on .. car is overheating. - 8/20/2009 7:27:28 PM

frdfandc

Posts: 3390
Joined: 7/31/2003
From: 15 mins from the Nats
Status: offline
Car: 2003 Chevy Silverado
1/4 ET: 15.420
1/4 MPH:

If you blasted the radiator with a hose from the front, you just clogged up all the vents. You need to spray the radiator from the BACK - engine side - out towards the grille. This will remove most of the bugs/stuff in the radiator.

_____________________________

Darin

ClickClick Racing Forums

FishForum

(in reply to pat_tm)

Post #: 7

RE: ac on .. car is overheating. - 8/20/2009 9:31:15 PM

pat_tm

Posts: 1500
Joined: 9/4/2008
From: northampton,pa
Status: offline
Car: 1965 Ford Mustang
1/4 ET: 14.600
1/4 MPH: 92.23

That's the way I did it. I'm not STA STA STOOOPID>> lol.

(in reply to frdfandc)

Post #: 8

RE: ac on .. car is overheating. - 8/20/2009 9:59:07 PM

turfmn

Posts: 4187
Joined: 7/31/2003
From: Bethel, De
Status: offline
Car: 1992 Ford LX hatchback
1/4 ET: 11.132
1/4 MPH: 127.11

This is a long shot, but did you look imbetween the condensor and the radiator for debris? My Crown Vic is really bad about getting leaves inbetween the two.

_____________________________

"When the people find they can vote themselves money,
that will herald the end of the republic."

(in reply to pat_tm)

Post #: 9

RE: ac on .. car is overheating. - 8/20/2009 10:08:01 PM

frdfandc

Posts: 3390
Joined: 7/31/2003
From: 15 mins from the Nats
Status: offline
Car: 2003 Chevy Silverado
1/4 ET: 15.420
1/4 MPH:

Just checking pat. Someone has to ask the STUUUUUUPID question.

_____________________________

Darin

ClickClick Racing Forums

FishForum

(in reply to turfmn)

Post #: 10

RE: ac on .. car is overheating. - 8/20/2009 10:09:49 PM

pat_tm

Posts: 1500
Joined: 9/4/2008
From: northampton,pa
Status: offline
Car: 1965 Ford Mustang
1/4 ET: 14.600
1/4 MPH: 92.23

Yeah but it's usually ME..

I was told there is a 2nd speed to the electric fan? Maybe it's not jumping to the higher speed?

(in reply to frdfandc)

Post #: 11

RE: ac on .. car is overheating. - 8/25/2009 2:26:35 PM

sc302

Posts: 1741
Joined: 7/31/2003
From: Joisey
Status: offline
Car: 1995 Ford GT

if the ac is on max, the high speed fan is always on. if ac is on norm, the high speed only kicks on when needed.

you could have one of several issues. run it on max at all times, and use the temp adjuster if it is blowing too cold. your immediate issue will be resolved. It is probably a simple coolant temperature sensor, this sensor kicks the fans on when it registers too hot.

A lot of people enable the high speed fan to always run by jumping a wire in the ccrm, doesn't exactly fix what is wrong but it is a work around and it helps the car run cooler.

(in reply to pat_tm)

Post #: 12

RE: ac on .. car is overheating. - 9/7/2009 6:33:12 PM

Red Mustang Gt 46

Posts: 1478
Joined: 7/31/2003
From: Hazard County Maryland
Status: offline
Car: 2004 Ford 2004 SVT Lightning
1/4 ET: 13.294
1/4 MPH: 105.18

Just read this...you probably need a new fan motor. The 2 speed switch is built into the fan motor and is probably bad (will only run at low speed or not at all). Be careful on letting it go too long because you will eventually burn out the plug that connects the fan motor. If that happens, you may have to buy another wiring harness.

NOTE* Although the fan may be running when you turn the AC on, the fan motor may seem like it's running up to speed when in reality, it is not.

I've replaced two so far in 11 years.

(in reply to sc302)

Post #: 13

RE: ac on .. car is overheating. - 9/7/2009 10:04:40 PM

pat_tm

Posts: 1500
Joined: 9/4/2008
From: northampton,pa
Status: offline
Car: 1965 Ford Mustang
1/4 ET: 14.600
1/4 MPH: 92.23

I'll have to see if that's a part the parts stores carry or if I have to go FOMOCO.

(in reply to Red Mustang Gt 46)

Post #: 14

RE: ac on .. car is overheating. - 9/7/2009 10:28:35 PM

Red Mustang Gt 46

Posts: 1478
Joined: 7/31/2003
From: Hazard County Maryland
Status: offline
Car: 2004 Ford 2004 SVT Lightning
1/4 ET: 13.294
1/4 MPH: 105.18

Napa sells them...

(in reply to pat_tm)

Post #: 15

RE: ac on .. car is overheating. - 9/8/2009 11:16:24 AM

MKurpicski

Posts: 957
Joined: 7/31/2003
From: Millersville, MD
Status: offline
Car: 1995 Ford Mustang Cobra

Let me know if that solves the issue for you, if it does I'll be right behind you...

mk

_____________________________

On the road again :D Holy chit it feels good to have her running right again.

(in reply to Red Mustang Gt 46)

Post #: 16

RE: ac on .. car is overheating. - 9/8/2009 11:34:45 AM

pat_tm

Posts: 1500
Joined: 9/4/2008
From: northampton,pa
Status: offline
Car: 1965 Ford Mustang
1/4 ET: 14.600
1/4 MPH: 92.23

I will be looking into how much a fan is at the parts store since i know i dont have a spare. I'll post as soon as I do. I know my buddy from another board has the same issue with just about the same temps in his '96 cobra. I used my scanner in his car and saw just about the same temps in the coolant.

(in reply to MKurpicski)

Post #: 17

RE: ac on .. car is overheating. - 9/9/2009 4:29:42 AM

Red Mustang Gt 46

Posts: 1478
Joined: 7/31/2003
From: Hazard County Maryland
Status: offline
Car: 2004 Ford 2004 SVT Lightning
1/4 ET: 13.294
1/4 MPH: 105.18

It takes about two minutes to pull the whole fan assembly out. I would inspect the plug on the fan and the wiring harness plug, check for any burn marks. Another way to tell is to run the car normally w/ the AC on and then shut the car off. The plug to the fan should be warm to the touch, if it's scorching hot then the fan/switch is bad.

(in reply to pat_tm)

Post #: 18

RE: ac on .. car is overheating. - 9/15/2009 7:38:07 AM

Red Mustang Gt 46

Posts: 1478
Joined: 7/31/2003
From: Hazard County Maryland
Status: offline
Car: 2004 Ford 2004 SVT Lightning
1/4 ET: 13.294
1/4 MPH: 105.18

By the way, if any of you are changing your fluid without one of these: http://www.autobarn.net/xxxw-uv-550000.html you should be. This tool makes a difference and works the first time...air in the coolant jacket (in the engine block) will make your engine run hot.

(in reply to Red Mustang Gt 46)

Post #: 19

RE: ac on .. car is overheating. - 9/15/2009 9:31:01 AM

pat_tm

Posts: 1500
Joined: 9/4/2008
From: northampton,pa
Status: offline
Car: 1965 Ford Mustang
1/4 ET: 14.600
1/4 MPH: 92.23

Never used one of those. But then again I haven't done much work on the newer cars YET. I may look into one.

(in reply to Red Mustang Gt 46)

Post #: 20

RE: ac on .. car is overheating. - 1/6/2010 9:52:29 PM

flysti06

Posts: 1
Joined: 1/12/2007
Status: offline
Car: Ford

my 96 cobra dose the same thing but no thinking a bout the fan thing when its hot the fan dosent seem to be spinning that fast i thought it would spin faster!!!!!

(in reply to pat_tm)

Post #: 21

RE: ac on .. car is overheating. - 1/31/2010 1:20:30 AM

Big Top GT

Posts: 42
Joined: 1/15/2004
From: Coral Springs, Florida ~ 33076
Status: offline
Car: 1998 Ford Cobra Coupe
1/4 ET: 14.100
1/4 MPH: 103.00

If the fan blows really low when you turn it on and works on high, it's not a bad motor.

You probably just need to replace this:

It's located below the glove box, sticking straight down. You can't miss it, since it's pretty much the only thing down there with a clip with wires sticking out of it.

Here's the old one that caused the problem:

(in reply to flysti06)

Post #: 22

RE: ac on .. car is overheating. - 2/15/2010 5:25:56 PM

Red Mustang Gt 46

Posts: 1478
Joined: 7/31/2003
From: Hazard County Maryland
Status: offline
Car: 2004 Ford 2004 SVT Lightning
1/4 ET: 13.294
1/4 MPH: 105.18

Big top, I think you are referring to the ac/heat blower motor...that is a thermal limiter which controls the blower motor and keeps the components from overheating...the motor I was referring to is the fan motor which cools the engine (he's having overheating problems).

By the way Pat, did you ever resolve the overheating issue??

(in reply to Big Top GT)

Post #: 23

RE: ac on .. car is overheating. - 2/17/2010 10:45:31 AM

pat_tm

Posts: 1500
Joined: 9/4/2008
From: northampton,pa
Status: offline
Car: 1965 Ford Mustang
1/4 ET: 14.600
1/4 MPH: 92.23

Not that I know of. Honestly by the time I really got to start troubleshooting it further it got cold and no ac needed. DAMN DEER!!. Come spring I'll be back on it.

on a side note. my load resister looked worse than the one pictured above. a used one from a parts car I got the airbags out of did the trick for my blower motor issue. ha ha

(in reply to Red Mustang Gt 46)

Post #: 24

RE: ac on .. car is overheating. - 3/20/2010 11:29:19 AM

Red Mustang Gt 46

Posts: 1478
Joined: 7/31/2003
From: Hazard County Maryland
Status: offline
Car: 2004 Ford 2004 SVT Lightning
1/4 ET: 13.294
1/4 MPH: 105.18

Here's another indicator that the fan is going bad, notice the bottom post charred? I had to replace another motor today...at least I got 18 months out of this one!