Battery Wiring Issue!

Thread Starter

cparke

Joined Aug 28, 2017
11
I had an incident recently where I got my car and began to start it, and the whole car went dark like it was fried or a main fuse got blown. No start, and now no more power anywhere! I went over the battery, but as soon as I touched one of the cables, all power returned. Wish I knew if it was the positive or negative (didn't have a meter with me at the time to check negative/ground continuity).

The cables at the battery seem tight. This also suddenly happened just as current was sent to the starting motor. The issue hasn't happened again, yet. Wiggling wires has not reproduced. How would you diagnose this?
 

MaxHeadRoom

Joined Jul 18, 2013
20,902
That smacks of a typical poor connection on the power cable, which often occurs, either at the battery connection point or on a connection point to the frame.
Max.
 

wayneh

Joined Sep 9, 2010
16,398
Yeah, a bad ground strap could easily cause this. Your engine may have several ground straps but they make them cheaper every day. In my experience it will wait to do it again until the worst possible moment.

Note, though, that the problem could be far more complex also. A single broken wire to the main computer can wreak havoc.
 

MaxHeadRoom

Joined Jul 18, 2013
20,902
I had exactly the same thing just happen on wife's auto, completely dead, I metered the battery and it was right up and the terminals tight, I gave them a slight reef for luck and she fired up, although they Felt tight, obviously it only took that fraction to make connection.
Been running ever since.!
Max.
 

BR-549

Joined Sep 22, 2013
4,938
Sometimes....due to battery corrosion.....the interior of the cables can become corroded. They can look like a sound cable and show no signs of corrosion. The next time you change a cable......cut the cable about an inch away from terminal and check it out.
 

DickCappels

Joined Aug 21, 2008
6,459
Had that happen a couple of years ago. Removed the battery cables and scrubbed the battery posts and the cable clamps with a solution of backing soda and water, then rinses thoroughly with water. Problem solved.
 

bwilliams60

Joined Nov 18, 2012
1,325
Your best bet is to perform a voltage drop test on the cables. Best to do it when you are cranking the engine over. Take your meter, place it on VDC. Take the black lead and place it on the battery negative post. Take the red lead and clamp it to a good ground on the engine block. Have someone crank it over while you read the voltage drop. If you can disable it from starting, even better (ECM fuse) It should be no more than 0.2 VDC. If it is, you have a bad connection or cable. Do the same for the positive side. Place the red lead on the battery positive post. Place the black lead on the battery positive post on the starter solenoid (Follow the battery cable down to the starter. The post with the most leads going to it. Large post). Again, crank the starter over and note the voltage drop. Should be no greater than 0.3 VDC. If so, replace cable or fix connections.
From your description, my first guess would be a dirty battery cable connection. If it was a cable, it wouldn't be intermittent.
Cheers
 

phranzdan

Joined Aug 4, 2017
40
I had an incident recently where I got my car and began to start it, and the whole car went dark like it was fried or a main fuse got blown. No start, and now no more power anywhere! I went over the battery, but as soon as I touched one of the cables, all power returned. Wish I knew if it was the positive or negative (didn't have a meter with me at the time to check negative/ground continuity).

The cables at the battery seem tight. This also suddenly happened just as current was sent to the starting motor. The issue hasn't happened again, yet. Wiggling wires has not reproduced. How would you diagnose this?
 

phranzdan

Joined Aug 4, 2017
40
Hi: Go to your auto parts store and purchase a cheap battery terminal cleaner. Remove the terminals one at a time and clean them thoroughly. Replace the terminals and tighten the clamping nut securely. This should take care of the problem.
 
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