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90scmxdream
04-18-2009, 03:20 PM
:confused:Hi guys
I need your help please,Iwent to santa cruz last sunday and the SC overheat on the hills(red line). and as yesterday I replacedthe thermostat,temperature sensor,new radiator cap and flushed the engine coolant system. I drive it to the hills and still over heating.can you please help me where else to look.
thank you ,Jose.P.S Dan,Merlon if you see this can you please give me a call,408-4380409cell.

91BLOWNBIRD
04-18-2009, 07:52 PM
its only over the hill, not on the streets or freeways? You can rent a cooling system pressure tester from Autozone and see if you are losin pressure anywhere...also sometimes the lower radiator hose pinches...also not always are new thermostats 100%, I always test mine in boiling water first. Blown head gasket is possible too :(

Ddubb
04-19-2009, 12:39 AM
I talked to Jose earlier .. he said he doesnt have internet access all the time. I asked him to check on a couple things like you mentioned - so we'll see if he calls back or updates here.

- Dan

jleopold
04-20-2009, 01:57 PM
could be a head Gasket ...
$99.00 bucks will have him back on track... --- if the HG is the problem.
My car is still working great... been over a year now since I used the Thermogasket... but you have to find the overheating problem first.

the-big-e
04-20-2009, 02:28 PM
My vote is for a plugged up radiator or a mashed up AC condenser.....

Ddubb
04-20-2009, 03:04 PM
could be a head Gasket ...
$99.00 bucks will have him back on track... --- if the HG is the problem.
My car is still working great... been over a year now since I used the Thermogasket... but you have to find the overheating problem first.


Id rather spend the $99 on brand new head gaskets than pour a bottle of crap into the engine.

- Dan

jleopold
04-21-2009, 07:53 PM
ya if that were only possible... but by the time you tear down the engine, get all the parts, put it back together and try it all out... you'd spend way more than $99 bucks. I've looked at every option and even a do it yourself job is $500-$700 in parts and then the time to do it is at best 10 hours.

...my ride is running great for $99 bucks...

Besides... I love T-birds be but we are not talking about a high performance top end car that gain value as it gets older. The stuff really works and I put it in the car back in September.

Ddubb
04-21-2009, 09:37 PM
I guess thats the difference ... you use a band-aid on a broken arm and I take it to the hospital.

- Dan

jleopold
04-22-2009, 05:25 PM
...uhhh ya...Anyway Jose...
You want your car fixed, take it to a good shop - do what you feel is best and it will be just fine. If you lived closer to me I tell you to take it to a local guy here in town that works on all the T-birds in Tracy and he as Ford Master Mech...he had the SC the first day it came out back in 1990. Sold the car to a guy here in town and I will tell you --- That car is the best SC in 100 SC's that I've seen -- Jim at Auto Specialies in Tracy is the MAN!

My car runs great with the product I used and either way, if the engine is really, REALLY toast you would still need to do a gang of stuff to get it running right.

John

90scmxdream
04-22-2009, 05:58 PM
Hi guys thank you to everyone for you reply's. Jleopold)there is a guy here in cambell he knows alot about are cars his mane is Tom but he is not very cheap,afterall is not very cheap to work in this cars.Don is OK togo over your house so you can take alook at it.jose

Ddubb
04-23-2009, 08:17 PM
.... uhhhh ... yeah ... anways ..... :confused:


UPDATE :

I took a look at Jose's car this afternoon, and here is what I have found.

Low speed fan comes on when it should at Temp.

Fan does not turn on when AC it turned on.

High speed and low speed Fan will work if circuits to PCM are triggered at harness.

Im getting about 4k ohms resistance between PCM and IRCM wiring for High speed fan.

Also, High speed fan holds circuit has completed circuit with Key Off / Engine Off ...
With Key On / Engine Off, High speed fan at PCM reads 8V.


.. Im leaning towards bad PCM / Wiring. Any second opinions ?

- Dan

91BLOWNBIRD
04-28-2009, 09:11 PM
electrical problems like that are rare, but could happen...

Ddubb
05-02-2009, 01:15 AM
Yeah .. all of the wiring seems to be OK. :confused:

The EEC wont turn the Low speed fan on when the AC is turned on. It does not put out the 12V signal to turn it on even with the AC pressure switch bypassed, but it will turn the low speed fan on if the ECT sensor is disconnected.

I picked up a spare EEC and that did not change anything.

Unless the EEC I picked up has the same problem, as MANY of the SC's on this website seem to have developed this problem .. nobody seems to have found a solution to this, other than cutting the #14 wire to the IRCM and forcing the fans to run all the time.

- Dan

91BLOWNBIRD
05-02-2009, 08:05 PM
there has to be a juntion in the wiring linking the two right? Do we know for sure that the you have the right idea about the low speed fan coming on?

Ddubb
05-02-2009, 11:05 PM
The High speed and Low speed fans are both controlled by the EEC directly.

The EDF Relay ( voltage inverter ) inside the IRCM makes the Low speed fan a little more versatile. It can be turned on / off by switching between a 12V and a ground. And when the ground is not present ( or cut like most people do ) - the fan will default to running all the time in Low speed as a fail-safe.

I spent some time yesterday searching through these forums for a possible solution to the "Low speed fan's not working when the AC is turned on". After not coming up with any results, Im convinced this condition exists in MANY Supercoupes and nobody has found a real solution to the problem.

I have the EVTM and wiring diagrams for the EEC, IRCM, etc etc .. as well as Shop manual with Flow charts and Diagnostics routines ... but none come to a clear solution - they all assume the problem is after the EEC.

- Dan