Did my SpeedCal die?

bonestock87

Founding Member

Dec 19, 2001

732

12

38

Cape Coral, FL

Mar 17, 2011

#1

• Mar 17, 2011

• #1

The facts: Started the '03 up to drive for the first time in over 2 months yesterday because of the awesome weather (finally). I had to jump it because I suppose the theft light and the speedcal drained the battery during the hibernation.
It started just fine so I let it idle for about 20 minutes, then I put it on a trickle charge for about 40 minutes. Then it sat overnight. It started right up this morning and I thought I was fine. I entered a school zone so when I looked down to make sure I was doing 15mph I saw the speedometer wasn't working and the odometer had all dashes, no numbers. All the other gauges are working fine. I stopped to fill the tank up and when I restarted it the speedomter was still not working but the odometer was now showing the mileage. The mileage didn't change on the 10 mile drive on in to work.
I checked the fuse for the cigarette lighter, since that's what powers the speedcal, it was fine. I don't know where to start. Any ideas? Thanks!

 

nyuk98gt

15 Year Member

Oct 10, 2000

1,427

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79

Chesterfield, MO

Mar 17, 2011

#2

• Mar 17, 2011

• #2

bonestock87:

Open the SpeedCal and see if the LED is on. If not but there is power to the SpeedCal (confirm with a voltmeter) then the S/C is dead.

Since your car has been parked for a while, it is quite possible that a squirrel or mouse has had a chomp at the wiring. Find the connector on the transmission and follow it along to confirm that the wiring is OK.

HTH,

Chris

 

bonestock87

Founding Member

Dec 19, 2001

732

12

38

Cape Coral, FL

Mar 17, 2011

#3

• Mar 17, 2011

• #3

I did open the box up just to see if anything was evident like something had fried maybe, but I didn't see anything wrong. I didn't notice an led light even when I installed it about 9 months ago, I'll have to recheck that. I've got it tapped into power from the lighter so I guess I could plug something in to make sure that has power. I sent Dallas Mustang's tech dept an e-mail, I'll see what comes of that.

Don't imagine this would have any relation, but my car died two seperate times when coming to a traffic light today when I pressed the clutch pedal to begin to slow down. I just let back out on it so the engine would start back up. It has never ever done that. I took it on to Advance and my battery (500 cranking amps) and alternator (14 volts) both checked out strong.

Thanks for the suggestions Chris. With a name like that you've got to be an extremely smart dude!

Chris

 

LarsD

Founding Member

Jul 2, 2002

2,680

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123

Texas

Mar 17, 2011

#4

• Mar 17, 2011

• #4

It might be dying when you are slowing down due to the VSS not putting out a signal (this would also explain your speedo not working). Is the cig lighter in our cars constant hot? I would think you would want the S/C tapped into a switched source (unless of course the instructions say otherwise).

 

bonestock87

Founding Member

Dec 19, 2001

732

12

38

Cape Coral, FL

Mar 17, 2011

#5

• Mar 17, 2011

• #5

Yes, the cig lighter is always hot in our cars, which is handy for several reasons. I followed the instructions to the T which told me to tap into power that way.

 

nyuk98gt

15 Year Member

Oct 10, 2000

1,427

6

79

Chesterfield, MO

Mar 18, 2011

#6

• Mar 18, 2011

• #6

bonestock87 said:

.... With a name like that you've got to be an extremely smart dude!

Chris

Click to expand...

Thanks but some who know me would argue.

Maybe your vintage of SpeedCal does not have an LED. Mine is pretty old and it does have one so I figured that they all do.

Try cleaning out the IAC valve. If it is not working then not enough air will enter to maintain engine speed. (The throttle body blade is not gas-tight but very little air gets past it when it is in the closed position. The IAC is the opened by the computer to keep the engine running when the t/b goes closed.)

If you have access to a code reader, or, better, a datalogger, you can find out what is going on under the hood. Some codes are pending so they don't show up (yet). Datalogging is the best thing since sliced bread since you won't have to throw parts on the engine trying to guess where the problem is.

HTH,

Chris

 

Maxpowers

Member

Sep 9, 2009

859

2

19

Pittsburgh, Pa

Mar 18, 2011

#7

• Mar 18, 2011

• #7

You could be having one issue here instead of two.

Take your battery out of the car and charge it overnight. 40 mins is not enough. You alternator may not be making enough power to charge the battery and charge the car.

 

bonestock87

Founding Member

Dec 19, 2001

732

12

38

Cape Coral, FL

Mar 19, 2011

#8

• Mar 19, 2011

• #8

Solution!

Taking the negative cable off the battery for a half-hour seems to have solved the problem. I have no idea what that has to do with the speedcal working or not but it's all good now. And the car didn't try to die on me anymore.
Thanks to all who posted!

 

nyuk98gt

15 Year Member

Oct 10, 2000

1,427

6

79

Chesterfield, MO

Mar 19, 2011

#9

• Mar 19, 2011

• #9

bonestock87:

Thanks for the update. Odd that "clearing the cache" of the PCM would do the trick but I'm glad that it worked out.

Now, go enjoy the warm spring weather by taking a nice cruise in the Mustang!

Chris

 

bonestock87

Founding Member

Dec 19, 2001

732

12

38

Cape Coral, FL

Mar 19, 2011

#10

• Mar 19, 2011

• #10

Now, go enjoy the warm spring weather by taking a nice cruise in the Mustang!

Chris

Click to expand...

Thanks buddy, I've been doing exactly that the last couple of days!