Vintage Mustang Forums banner

1 - 5 of 5 Posts
G

·
Guest
Joined
·
0 Posts
Discussion Starter #1
I am having a problem with the power supply in my 70 coupe. The car is acting like the battery is dead. The dome light is very dim and it goes out when I step on the brake and the brake lights try to light up. Jumping it doesn't help though. I hooked it up to another car and got NO improvement at all. I had a problem with the electicity not long ago and solved it by replacing the starting solenoid switch. Any ideas what could be wrong?

Oh, the alternator is also new within the last 10 months, but that shouldn't be an issue until the car is started anyway. Thanks for any ideas.

Chris
 

·
Registered
Joined
·
2,750 Posts
Check negative battery lead...clean ends and make sure you have solid connection to the engine block. Check chassis ground between right rear of engine intake manifold and firewall. Make sure this wire is pencil thick and has good clean connections at both ends. Also check positive battery cable for cleanliness and being solidly installed.
 

·
Registered
Joined
·
646 Posts
Try replacing the voltage regulator (if the 70 stang has one). I had a problem with the same symptoms as you describe on my 68 coupe. A new voltage reg fixed the problem. Also, have your battery tested to see if it's still good.

Deathman68
 

·
Just some guy
67 coupe, 69 Sportsroof, 86 hatchback
Joined
·
20,755 Posts
If you tried jumping it off with another car, my first suspect would be the cables. Often cable corrosion isn't obvious until you disconnect them, sometimes not even then. Don't forget the ground cables.
 

·
Registered
Joined
·
109 Posts
Wow, this is the first time I may actually be able to help someone.

I can almost guarantee you that this is ground issue. Makes sure that you the if something has been painted lately that you get a good metal to metal contact.

Good luck,
wsgts
 
1 - 5 of 5 Posts
Top