Car No Start. Found Problem (I Think)


Howard

GT Owner
Mark IV Lifetime
Apr 26, 2007
1,136
Florida/North Jersey
Short version: All the symptoms of a dead battery....really dead. Hard to believe since there were no prior symptoms and I keep the car on a battery maintainer and use the car regularly. No radio, no gauges, no dash idiot lights, no horn. Barely enough juice to open the doors. Opened and closed the door and everything came back! Immediate engine start. Took the car out for a ride and after a three hour stop, same symptoms. Jumper wouldn't work; but by that time I didn't think the problem was the battery anyway. I removed and replaced the negative battery terminal, hoping something would reset. It didn't. Wiggled all the fuses and relays. No change. Loosened and retightened the frame ground bolt. THAT WAS IT! Everything came back. Now, this may sound like a familiar story but I filed and cleaned that connection myself two years ago. I'm now convinced that you can't file and forget about that connection. It requires maintenance every couple of years. Mine does, anywway. An anxious day with a happy ending.

Howard
 
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jaxgt

GT Owner
Mark IV Lifetime
Jul 12, 2006
2,795
Something similar happened to me once. Similarly crazy and erratic symptoms.
 

Kayvan

GT Owner
Jul 13, 2006
4,782
Do u file the actual frame bar? Or that seated-threaded washer that bolt screws into?

I had same exact symptoms; esp opening door triggered restart

It seemed to be after a specific time too: 20 or 40 min

Ibcould never get a straight answer as to if other GTs sand frame bar or have a seated washer?
 

Howard

GT Owner
Mark IV Lifetime
Apr 26, 2007
1,136
Florida/North Jersey
I filed the face of the threaded insert in the frame, as well as both faces of the circular cable termination. I think the best way to deal with this is to add a redundant ground wire. I will look tomorrow for a good location to bolt an additional cable from the battery to the frame.

Howard
 

Specracer

GT Owner
Mark IV Lifetime
Nov 28, 2005
7,088
MA
Consider adding some dielectric grease, I add this to any electrical connection.

http://www.permatex.com/products/au...e/auto_Permatex_Dielectric_Tune-Up_Grease.htm
 
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paul b

GT Owner
Nov 2, 2006
810
How about a copper stud and nut instead of stock bolt?
 

Indy GT

Yea, I got one...too
Mark IV Lifetime
Jan 14, 2006
2,526
Greenwood, IN
Or use a "star" washer between the frame ground and cable end.
 

RALPHIE

GT Owner
Mar 1, 2007
7,278
Or use a "star" washer between the frame ground and cable end.

(And, make it a stainless steel star washer)
 

Howard

GT Owner
Mark IV Lifetime
Apr 26, 2007
1,136
Florida/North Jersey
FGT Ground Strap 1 (1).JPGFGT Ground Strap 1 (2).JPG

I installed the redundant ground strap today. I found a convenient threaded ground, wire brushed it to bare metal and replaced the anodized Torx bolt with a mild steel hex head. A resistance measurement shows no measureable resistance between the new location and the co-existing factory location. Any auto store will have the 20-inch, small hole braided strap I used. This may not help, but it sure can't hurt. I want no repeat of yesterday's excitement.

Howard
 

BlackICE

GT Owner
Nov 2, 2005
1,416
SF Bay Area in California
View attachment 21547View attachment 21548

I installed the redundant ground strap today. I found a convenient threaded ground, wire brushed it to bare metal and replaced the anodized Torx bolt with a mild steel hex head. A resistance measurement shows no measureable resistance between the new location and the co-existing factory location. Any auto store will have the 20-inch, small hole braided strap I used. This may not help, but it sure can't hurt. I want no repeat of yesterday's excitement.

Howard

Thanks for sharing. I suspect you won't have any more ground problems. Do be careful how the braid is routed, because over time it made chafe and cause paint damage.
 
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Kayvan

GT Owner
Jul 13, 2006
4,782
Id like some photos of peoples ground sanding, filings, brushings to bare metal !
 

jbyrnes

FORD GT OWNER
Mark II Lifetime
Jun 13, 2006
224
Louisville CO
Consider adding some dielectric grease, I add this to any electrical connection.

http://www.permatex.com/products/au...e/auto_Permatex_Dielectric_Tune-Up_Grease.htm

I agree with specracer. Bare aluminum will quickly oxidize - and the oxidized layer is a bad conductor. Is this connection bare / dry from the factory? The aluminum may have a conductive alodine coating but that's pretty fragile and the toothed washer will gouge through it and expose the bare al. There's also a galvanic corrosion problem whenever dissimilar metals are in tight contact with each other in the presence of water / humidity - like the steel screw with the al. frame. Not a problem if the coatings are maintained but they're compromised during torqueing. The joint will stay conductive if you keep out the water and oxygen. Grease is a great fix if you don't mind the mess.
 

Howard

GT Owner
Mark IV Lifetime
Apr 26, 2007
1,136
Florida/North Jersey
I will add dielectric grease to both the original and new grounds. Couldn't hurt.

Howard
 

RALPHIE

GT Owner
Mar 1, 2007
7,278
I agree with specracer. Bare aluminum will quickly oxidize - and the oxidized layer is a bad conductor. Is this connection bare / dry from the factory? The aluminum may have a conductive alodine coating but that's pretty fragile and the toothed washer will gouge through it and expose the bare al. There's also a galvanic corrosion problem whenever dissimilar metals are in tight contact with each other in the presence of water / humidity - like the steel screw with the al. frame. Not a problem if the coatings are maintained but they're compromised during torqueing. The joint will stay conductive if you keep out the water and oxygen. Grease is a great fix if you don't mind the mess.

By the way, J., I still love your splash guards!! :thumbsup
 

paul b

GT Owner
Nov 2, 2006
810
A second ground should be easy with a new dual terminal battery,
 

bonehead

GT Owner
Mark II Lifetime
Aug 18, 2012
2,814
Houston, TX
Have to bring this thread back from the dead. Have had battery/ground issues for the last few weeks that I can't seem to shake. Got a CEL a few weeks ago as I was pulling out of the driveway. Used an OBDII scanner and.....no code. Car drove fine so I ignored it hoping it would either go away or I'd find some time to bring it in to have it checked out. Fast forward a few weeks and after a wash, I went to start the car and pull it into the garage. Tick tick tick and the gauge lights flickered but no start. Half assed cleaning the neg terminal of quite a bit of corrosion and loosened/retightened the ground. Voila! Or so I thought. Shut it down and tried again. Same flickering and inability to start the car. Cleaned the terminals and the ground again...got lights but still had a CEL and the car wouldn't start. Left it until this morning. Did a much more thorough cleaning of the corrosion on the terminal and the ground/frame contact and used dielectric grease. Car started fine, CEL was gone, drove off to my destination....you know where this is going.....Starting my trip home and turned the key. CEL was back, but the car luckily started this time and I got it back home into the garage.

What am I missing here? Clearly what I'm doing is working. But only for a single start and the problem comes right back. If a second ground is the answer, I'll do it. The concerns over corrosion mentioned above are what give me pause. Suggestions?
 

twobjshelbys

GT Owner
Jul 26, 2010
6,060
Las Vegas, NV
Did you replace the battery?
 

bonehead

GT Owner
Mark II Lifetime
Aug 18, 2012
2,814
Houston, TX
A year ago.
And the car is ALWAYS plugged into a CTEK when parked.
 

twobjshelbys

GT Owner
Jul 26, 2010
6,060
Las Vegas, NV
Could still be battery isn't charging due to ground connection problems. Try another battery? Doesn't need to fit, just sit. Jumper cables if you don't have a loose one. I don't like battery chargers.
 

bonehead

GT Owner
Mark II Lifetime
Aug 18, 2012
2,814
Houston, TX
Quite possible. I need to get my hands on a multimeter and check the battery itself. But the instantaneous response to just fidgeting with the negative lead/ground cable lends me to believe it's not the charge on the battery.