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Item Posts    Sort Order

overheated cobra

 
murdochdemers
New User
Posts: 6
Joined: 12/13
Posted: 03/24/14 01:57 PM

my 95 overheated yesterday. I had the air on for the first time this season, probably for 30 miles or so and when I pulled in the driveway I could see the steam arising. my temp gauge does not work (I suspect this may have happened to the previous owner)so I had no inclination it was about to happen. there are no leaks, I refilled and cycled the motor to heat with no air on and it seemed fine. the fans went on and off 3 times. I did not try it with the air on. is there a relay that cycles the fans more when the air is on or is something else faulty?  

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wayne712222
User
Posts: 65
Joined: 10/13
Posted: 03/24/14 07:06 PM

the fan motor has 3 wires on it... its  TWO speed fan...

a black ground wire. to location G101.. hmm..

an RED and orange stripe wire..

an ORANGE and blue stripe wire..  

there is as far as i can tell and i am taking that you have the 5.0 version or 5.8 version.. not a 4.6L version as the wiring is similar..  i just have not compared them  yet..

and PLEASE DO NOT PROBE THE WIRING INTO THE CCRM or the harness that goes into it either..  

first... find the harness coming off the fan.. its usually at the core support.. find the ground wire connection for it..   examine the wiring into the crimp terminal.. are the strands broken.. is the ring terminal tightly attached and actually clean.. take it off and wire brush both sides..  its probably an 8 gauge wire.. others are in that year range..

Fordbatterytobodygroundwire Zps50c65ba5


Fordcoresupportgrounds Zpsc9737ea7


if you don't have a good ground.. the system will NOT spin the motor fast enough to cool the engine..

with the engine running and the fan cycled on when the thermostat opens.. the fan may be on at low speed..   reach over and turn on the AC system. and see if the fan spins faster.. louder...


to verify you have NOT damaged the cylinder head gaskets..

take a piece of sandwich wrap..  lay it over the radiator filler neck.  push a depression into the film.. place a rubber band around the filler neck to seal the film..   crank or start the engine.. for a timed 15 seconds..  if the depression stays in film.. you might be OK.. if it puffs up.. you are in trouble..


i have to dig thru some info on how to use a scan tool or code reader to active the fan driver circuits for on the car testing..

i have the diagram.. but i am still highlighting it.. as each model is slightly different.. and

please also check the negative battery connection to the inner fender.. it must be clean and tight..   when the fan is on.. the electrons flow from the negative battery post to the negative cable to the inner fender ,, across the core support and to the fan ground connector..  if any of those are loose or frayed.. you will have issues..  

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Andrea Pollett
New User
Posts: 3
Joined: 03/14
Posted: 03/26/14 07:42 AM

thermostat take it out if the spring does not compress its bad most often it is the thermostat it opens up and wont compress so basically telling the car im hot send more water also you can pull it out and leave it out for a while but they are inexpensive xD Grin  

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Andrea Pollett
New User
Posts: 3
Joined: 03/14
Posted: 03/26/14 07:42 AM

thermostat take it out if the spring does not compress its bad most often it is the thermostat it opens up and wont compress so basically telling the car im hot send more water also you can pull it out and leave it out for a while but they are inexpensive xD Grin  

Post Reply
Andrea Pollett
New User
Posts: 3
Joined: 03/14
Posted: 03/26/14 07:43 AM

thermostat take it out if the spring does not compress its bad most often it is the thermostat it opens up and wont compress so basically telling the car im hot send more water also you can pull it out and leave it out for a while but they are inexpensive xD Grin  

Post Reply
murdochdemers
New User
Posts: 6
Joined: 12/13
Posted: 03/26/14 08:50 AM

thank you for the responses. wayne I checked the items you suggested and all were okay. the thermostat is new, I replaced the original with a 190, flushed and refilled a few weeks before this event. I also found a broken line at the vacuum tee that feeds over to the a/c. repaired and it did smooth out the idle. took it out last night for a 40+ mile cruise I traffic with no problems but I did not run the air.  

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wayne712222
User
Posts: 65
Joined: 10/13
Posted: 03/26/14 10:53 AM

wonderful...

please check the radiator cap also...

with the cap installed..  and the engine warm..  squeeze the upper hose.. there should be pressure held in by the cap...

there are some caps.. that have a LOOSE center disc .. find one that's spring loaded tight against the rubber seal..

usually only one part number off.

lack of cooling system pressure will effect the boiling point of the coolant..

each pound of pressure increases the boiling point 3F..

so.. 13 pounds increases the boiling point 39F..

a working thermostat blocking the massive flow created by the water pump and the only flow getting thru is via the heater core or bypass hose will increase the mechanical  coolant pressure in the block and heads to prevent hot spots from boiling during high speed runs...


you might want to test the AC and see if the fan kicks from low speed to high speed when you do so..  

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