2005 Ford GT Charging Issue


samson

GT Owner
Nov 3, 2014
51
Harrogate TN
I could use some help on fixing my 2005 Ford GT. Recently I noticed the volt meter was dropping and once I accelerated it would come back up. This lasted a few miles and then the battery was dead. I replaced the battery and then the alternator and still it will not charge. I have checked all the fuses in the trunk and they are all good. If you charge the battery the car will perform fine until its drained again. The voltage drops and the check gauges light comes on, but no battery light. I read that a bad light bulb in the battery light can cause this? I don't want o take the dash apart if anyone here knows any other things to check.

Thanks,
Samson
 

Howard

GT Owner
Mark IV Lifetime
Apr 26, 2007
1,135
Florida/North Jersey
Have you checked and cleaned the battery ground-to-chassis cable?

Howard
 

1434gt

GT Owner
Aug 29, 2006
233
I could use some help on fixing my 2005 Ford GT. Recently I noticed the volt meter was dropping and once I accelerated it would come back up. This lasted a few miles and then the battery was dead. I replaced the battery and then the alternator and still it will not charge. I have checked all the fuses in the trunk and they are all good. If you charge the battery the car will perform fine until its drained again. The voltage drops and the check gauges light comes on, but no battery light. I read that a bad light bulb in the battery light can cause this? I don't want o take the dash apart if anyone here knows any other things to check.

Thanks,
Samson
i will contact the gt guys they know this car inside out,how did your car do at the ocala half mile ?
 

junior

GT Owner
Mar 9, 2007
1,151
So Cal
Are you sure the new alternator is properly working ?
 

samson

GT Owner
Nov 3, 2014
51
Harrogate TN
Its still in its OEM location with the paint marks on it, I can take it off and clean it good, but it looks spotless.
 

samson

GT Owner
Nov 3, 2014
51
Harrogate TN
It went 177mph but was cutting out off the line due to the low voltage and we stopped racing it after 3 passes. It will go 180's easy with some more practice runs and voltage.
 

07XL0027

GT Owner
Mark IV Lifetime
May 20, 2012
1,546
Austin TX
Its still in its OEM location with the paint marks on it, I can take it off and clean it good, but it looks spotless.

I've heard the paint between the grounding strap and the body can cause issues. Dr Frank told me that once.


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1434gt

GT Owner
Aug 29, 2006
233
It went 177mph but was cutting out off the line due to the low voltage and we stopped racing it after 3 passes. It will go 180's easy with some more practice runs and voltage.

nice runs ,one of my best friends was talking to you.thats how i know about your car.
 

samson

GT Owner
Nov 3, 2014
51
Harrogate TN
He showed me a picture if your car, same colors and hennessey package as I have. I will try to get the car out of the car hauler tomorrow and get started working one this issue.
 

samson

GT Owner
Nov 3, 2014
51
Harrogate TN
I checked the voltage on the following

Battery 12.2 v (not running)
Alternator 11.7- to 11.4v while running
Battery 11.3- to 11.6 while running
Alternator exciter wire 11.4 v (not running)

I am thinking this new alternator is not putting out enough volts, I have checked everything else I can find.
 

BlackICE

GT Owner
Nov 2, 2005
1,416
SF Bay Area in California
I agree sounds like the alternator isn't putting enough current out if any at all.
 

BtwoG

GT Owner
Dec 8, 2013
1,039
Atlanta, GA
Alternator voltage should be closer to 14V.
 

Howard

GT Owner
Mark IV Lifetime
Apr 26, 2007
1,135
Florida/North Jersey
Sounds like the alternator, but I would still service the battery ground connection before making any rash decisions.

Howard
 

Silverbullitt

GT Owner
Mar 3, 2006
1,757
Lago Vista, TX
Where is the voltage regulator? If it is separate from the alternator it needs to be checked.