Fried Battery Cables...Random No Electrical Power

DamnedButDetermined · June 21, 2019

I just got this truck and have been weeding through the issues going on. The most annoying of them being the complete lack of electrical power that just randomly happens. I can't figure out which process fixes the problem at the moment...Wiggling the negative terminal or wiggling the possible terminals. The actual battery connections are very clean and tight but the wires are exposed through the jacketing which is burned off pretty bad. It was like this when i got it but I didn't notice it until the random no power issue first cropped up.

I also can't tell for sure if the battery cables/terminals are getting EXTREMELY hot from the 100* heat index outside combined with engine heat while driving, but when the no power issue happens it feels like the positive cables are crazy hot and I can only hold them for a few seconds. The metal terminal is so hot that I can only tap it with my fingers.

EDIT: I forgot to add some info...Today driving home I hit a pretty good size pothole and the truck lost all electrical power, motor shutoff, and then electronics turned back on 5 seconds later and so did the motor all by itself. I was driving about 60 mph when this happened and i just coasted until it turned back on. You could sense something was going on electrically because the AC blower speed would fluctuate and the motor didn't run quite as good as it normally does. I think something with the power/ground wires is breaking connection under bumpy conditions.

Is this a common issue that is easily fixed or do i have big short somewhere that is causing this crazy heat? Here are some pictures that show how hot the cables have gotten...

Edited June 21, 2019 by DamnedButDetermined

riverbanks · June 21, 2019

Take a look at starter connection,and + cable near it,that is not fused from battery to it, everything past that is protected

DamnedButDetermined · June 24, 2019

I haven't had a chance to get under the truck but it looks like the worst of those cables is the one that goes to the alternator. Do you think maybe something in the alternator is causing the short and that is what has fried that cable?

I just ordered all new positive and negative cables for the replacement, but i don't want to install the new cable on the alternator if it will fry that cable too.

tbarn · June 24, 2019

That issue is most likely caused by a poor connection at that nut. Is loose or was once loose. New cables and make sure they are tight should take care of it.

PPK · June 24, 2019

The alternator is rated over 100 amps.. That would require a #1 AWG wire at least.. i think that the connector looks a little light for continuous 140 Amps of current... and the insulation is also a little weak for continuous current and the heating. I hate to see crimped connectors on large wire like this. its a lot better to have fargo type compression connector. Wire gets hot and cold and sooner or later works itself loose from the needed tightness to carry the current without heating...

You can do better with parallel conductors, smaller wire, but two runs... solder the terminal ends.

This is a critical area when you have a truck full of sensors and computers... Yikes.

davester · June 25, 2019

I would suggest not using 2 wires, even if the overall current rating is higher than a single, larger wire, as if one of the wires fails, or is accidentally left disconnected, the other wire is automatically significantly overloaded...

sefiroxx · June 25, 2019

The middle wire is corrupted by the looseness in the strands. The current in a twisted strand wire is allowed to find the the least resistant path and will jump strands as needed. Once the strands become loose and distant from each other, current is less likely to jump (increased resistance). But, if the heat builds up on a single strand due to high current, the resistance will increase to a point where the current will jump the air gap. This jump will often result in plasma with a very high temp that can fry the strands around it.

So, be sure to use an attachment that keeps the strands wound rather than flattened.

DamnedButDetermined · June 26, 2019

Thanks everyone. I hav ordered ACDelco OEM replacements for all battery cables so hopefully they will have proper terminals.

DamnedButDetermined · June 26, 2019

I replaced all of the battery cables today, snapped the positive terminal off the starter, so i has to install a new starter, and just for good measure i installed a roll up bed cover ;) After the new cables the engine runs much more steady, the AC blower doesn't fluctuate anymore and the cables never get anywhere close to warm after a start or while it is running. So I think that problem is fixed.

After the cable swap I noticed that the voltmeter in the dash would fluctuate around. Sometimes it was pushing over 14v and others it was down to 10v. I couldn't figure out the rhyme or reason but I think after a few trips the voltmeter remained steady at 14v or slightly higher. I will check again tomorrow to see if it was just getting settled in due to low voltage in the battery because of the bad cables before, or if I have some issue with the alternator.