JustBreathe Posted July 11, 2008 Report Share Posted July 11, 2008 Anyone have any ideas as to why my negative battery cable is getting so hot while the engine is running? Any help appreciated. Thanks Link to comment Share on other sites More sharing options...
jisleyjr Posted July 11, 2008 Report Share Posted July 11, 2008 Might be corroded out thus increasing the resistance creating heat Link to comment Share on other sites More sharing options...
travs87tsi Posted July 11, 2008 Report Share Posted July 11, 2008 yes most likely corroded. in some really bad cases the corrosion will even start going into the negative cable so make sure you inspect the cable good too. Link to comment Share on other sites More sharing options...
JustBreathe Posted July 11, 2008 Author Report Share Posted July 11, 2008 I dont really see any corrosion at all. I guess Ill try changing the cable and see how that goes Link to comment Share on other sites More sharing options...
Whiplash Posted July 11, 2008 Report Share Posted July 11, 2008 You have a bad ground somewhere. It could be bad connection, starter, etc,... Link to comment Share on other sites More sharing options...
Technology Posted July 11, 2008 Report Share Posted July 11, 2008 Well, you don't have to have corrosion to have a bad cable. Try replacing it, they are cheap. Link to comment Share on other sites More sharing options...
Indiana Posted July 11, 2008 Report Share Posted July 11, 2008 Where it bolts to the frame of the car below the battery tray and is attached to the left side of the block clean those rusty surfaces, you can get a new cable from the battery to the block then a short one from the block to the frame, get #2 cables or #4 maybe if you think a #2 is too large Link to comment Share on other sites More sharing options...
macrophage Posted July 11, 2008 Report Share Posted July 11, 2008 Its hot because you have High Ampere"resistance" going back to ground. All high amp connections must be grounded properly from start to finish otherwise heat. This is why audio amplifiers burn out because the wires are 18G and the amp puts out 600 real watts. its like blowing thru a straw. Link to comment Share on other sites More sharing options...
mikec Posted July 11, 2008 Report Share Posted July 11, 2008 Got a decent voltmeter - a digital one? If so, try this: Have a helper hold the meter's black (-) lead to the TOP of the battery post - not to the wire or wire terminal... go right to the battery after you sand/scrape a little clean spot in it. Start the engine and let it idle. Crank up the a/c and turn on the headlights to put some load on the battery system. Touch the red (+) meter lead to the outside of the wire terminal. In theory you'll see 0.0 volts... but if you see a few tenths you've confirmed a lousy connection. Now touch the red meter lead to the negative battery cable itself... again you should see 0.0 volts. If it's higher than the last step, the cable to terminal crimp is lousy. Now touch the red meter lead to a good chassis ground point... you'll probably see about 0.2 volts now; if you get more than that then the negative cable to chassis connection (below the battery) is crappy. Now touch the red meter lead to the engine block... should see no more than 0.2 volts unless the cable-to-engine bolt (behind alternator) sucks or the negative cable itself is oxidized/corroded leading to high resistance wire. Many auto parts stores, and Harbor Freight Tools, sell small battery post cleaner tools. One looks like a silver "Dalek" from the Doctor Who shows; just a big silver thimble. Twist the top off and you've got a wire brush to clean the insides of the wire terminal ends; the body has an opening to fit over the battery posts to clean the battery. Works GREAT. Others look like "brass knuckles" made of plastic with wire brushes poking out everywhere; they work pretty well too. Check out Harbor Freight Dalek battery terminal cleaner mike c. Link to comment Share on other sites More sharing options...
Shelby Posted July 12, 2008 Report Share Posted July 12, 2008 you can not look at a connection and always tell it it is bad or not i have seen what apear'd to be a perfict looking cable end be totaly open due to corrosion inside Link to comment Share on other sites More sharing options...
JustBreathe Posted July 12, 2008 Author Report Share Posted July 12, 2008 there is no voltage drops at any of the ground connections so in going to reinforce the grounds with some extra wiring. im wondering, because the previous guy did a gm alternator conversion, maybe i got his hack job connections wrong. would a wrong connection on the alternator, even though its working, cause a hot ground? Link to comment Share on other sites More sharing options...
Shelby Posted July 13, 2008 Report Share Posted July 13, 2008 huge diff in testing a connection with a low voltage meter and doing so while it's carrying a 300 amp load a connection that is geting hot means it's makeing a very poor connection or the area carrying the actual load is too small for the amprage thats being carry'd it the cable end is a replacement end,,completely disasemble it and clean ALL parts,, if it's an oem cable it may have a poor internal connection that can't be seem it may also have a super heavy load due to a short in the starter or a cable thats touching a ground while starter is operateing a normal start should draw less then 300 amps while runing but a worn out starter can draw as much as the batt is capable of giveing out the cable geting hot while the engine is runing usually means the alt to batt wire has a poor connection or some thing is the vehicle is shorting out ,the oem fuse links is there to protect the major electrical system parts from this shorting out and burning wires Link to comment Share on other sites More sharing options...
JustBreathe Posted July 14, 2008 Author Report Share Posted July 14, 2008 Thanks for all the help. I skipped all the hoopla and went straight to Walmart, bought some 2 gauge ground wires and regrounded my block and chassis. The block now has 2 grounds from the side post, also one to the chassis from the side post and one straight to the alternator from the top post. Took care of the problem. Learning a lot on this site. QUOTE (shift1313 @ Jul 9 2008, 09:35 PM) [No car has] the same kind emotional involvement as the quests do <<< very true! Link to comment Share on other sites More sharing options...
macrophage Posted July 14, 2008 Report Share Posted July 14, 2008 Another thing about connections is that when your using high amperies dont solder the joint, crimp it instead because the heat can cause the solder joint to melt. Link to comment Share on other sites More sharing options...
Shelby Posted July 14, 2008 Report Share Posted July 14, 2008 if you have enought heat to remelt the solder you have too small a cable/wire or a dead short Link to comment Share on other sites More sharing options...
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