[ds968]

Only after about 10 minutes of driving the battery cables' connections ( tne end pieces which go on the battery terminals posts ) get EXTREMELY hot ! So hot, that if you touch them they'll singe the skin on your fingers . The battery ( which is only about a year old ) when cold , reads about 12.3 V , and when the engine is running the charge coming in seems to be about 12.5 - 12.6 , but not sure what's happening , and why the cable ends are as hot as they are . And the battery has been very sluggish when starting the car after three or four days of sitting, so I'm wondering if by some chance the alternator is overcharging and frying the battery ? Is that ( excessive AMPS output while the voltage stays at a normal level ) , even a technical possibility ? I don't have an amp meter only voltage one , and I have no clue about these things anyway so just trying to figure out what's going on .. We've had 102 - 106 mid day temps temps here for an entire week so I'm sure that did not help matters with starting , but it does not explain what's causing the cable connections to get as hot as to burn your hands if you touch them.

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[John]

ds968, Current through resistance equals heat. First step is to clean those terminals and the inside of the connectors. If that doesn't help, the resistance has to be inside the battery, and transmitting the heat to the terminals, meaning borrow/get a different battery and try it. Another possibility is the cable wire to connector connection of your cables themselves (these cables are now 20+ years old). Sluggish starting can also be due to internal and/or connection resistance. Those charging voltages look ok if not a little low. Your local auto parts store should have a battery tester with which they could identify any internal resistance, cable resistance, or excessive charging current.   ...good luck, John

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[ds968]

Thanks John, very helpful tips , so will give that a try. The connectors and the posts are both very clean ( I used the " battery brush " recently to do that ) so I'll stop by the local Interstate battery shop , since that's where I bought the battery last year, and have all the internal battery resistance, as well as anything else they can check tested ..they have all sorts of instruments for that.

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[az968]

Dan, also check over the cables themselves for corrosion that could be on the cable, esp at the other end. Both ends can corrode. Esp if the connection isn't tight. This would be the tip, your problem child?

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[MCL968]

I concur completely, a loose connection is a hot connection. I'm betting that there is corrosion inside of the terminal. We had corrosion inside of one of the clamps on the motorhome we used to tow our race car. It was so hot that it melted my thumb when I tried to twist it to see if it was loose. Sounds like you have the exact same situation.

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[flash]

that charging voltage is a full volt low.  those cables should not be that hot.  you have a problem.  do not drive that car until you get it fixed.  failure to do that can easily result in major wiring meltdown.

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[ds968]

The cables LOOK to be in remarkably good shape , but I realize that may mean little or nothing . Also for whatever it's worth the cables themselves were not warm , only the clamps were hot ( and possibly the battery posts themselves ).


Oddly the instrument panel's voltmeter hovers around 13.5 or slightly above for a little while when the engine starts , until I drive off and then it drops to just a hair over 12 bar , with the AC on, the radio on, etc.. but it's the external voltmeter which showed a 12. 5 /. 6 reading after starting and idling . I presume the external voltmeter is more reliable than the instrument panel one, but that's not a sure thing either ..


Anyway, I'll give the cable connections a thorough cleaning and close up inspection tomorrow , and also take the battery down to the local Interstate shop to have it checked out and see if it has any issues .


Bob ( AZ ) - yes, the tip .. of course ..

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[flash]

it should charge AT LEAST 12.8 at idle

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[ds968]

I disconnected the battery today ; the connections are as clean as can be , and they were also tightly secured . So that eliminates the corroded or loose contact possibilities . The cables look to be in very good shape. Unfortunately I can't see the other end of the cables at the alternator because the view is completely blocked, with the supercharger set up in the way , but I'm going to assume those are also in very good shape because my mechanic replaced the voltage regulator about six - nine months ago and considering he notices the smallest detail, especially if something looks problematic he would have mentioned that ..


So I removed the battery and used a voltmeter to see what it reads : 11.9 V. I then took the battery to the Interstate shop to have it tested ; they said they need a minimum of 24 hrs but more likely 48 hrs to put it through all the tests in order to detect if there are any resistance problems, or inability to be fully charged , or ability to hold the charge level, etc. That's the second process of elimination step which does not cost anything .


The remaining step ( IF it's not a bad battery that's causing the problem ) eg. replacing the alternator is more expensive and a complete PITA of a job, even for an experienced mechanic... Damn, the ONLY drawback of a SC on these cars is changing certain parts which are that much more difficult to access .


Will revert in a couple of days when I get the news on the battery tests .

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[flash]

even if you find the battery to be a problem, that does not eliminate the alternator, or the cables.  one of those could have fouled the battery.

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[ds968]

True, but then what ? How does one know if it's the cables or the alternator ? I'd hate to go through a huge job changing the alternator and discover that it was ok and it was really the cables . So do I change the cables first and see how that goes , before tackling the alternator ? Or is the access needed to change the cables pretty challenging as well ?

And again, what if it's an entirely different electrical problem ( though no idea what that could be other than cables and / or alternator ) , how does one troubleshoot that ?


Another question : if the alternator or cables indeed caused a deterioration of the battery, it would be only in case the battery gets overcharged ( eg the hot connectors ), not just charged at a slower / lower voltage pace ( 12.5 v ) , right ?

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[flash]

lead/acid batteries can fail if they are either undercharged or overcharged.  they want to receive voltage in a fairly tight range.

 

unfortunately the only way to know if the alternator is any good is to remove it and bench test it.  i haven't seen anybody with the gear to test an alternator in the car in a very long time.  i have it, but even i haven't used it in years.

 

cables can be resistance tested, but that may or may not tell the whole story.  if, for example, there was a break in the cable somewhere, and only a few strands were intact, it would show no resistance to speak of, but not be able to carry the amperage, and then get hot.

 

i know that doesn't help much.  sorry.  if it makes you feel any better, if i had to take a stab at it, i would say that 3 out of 4 times i have to diagnose a charging problem, and the first diagnosis doesn't turn out to be right, i end up having to replace everything in the system.

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[MLB]

If u havent replaced the starter to alt wiring harness, i would check that with fear and trepidation ;0)

Had to remanufacture mine from scratch in april.

It was horrible, only crispy crackely insulation bits inside.

Flex it along the entire length, listen for rice crispies

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[tejon007]

Well, I was working on my A/C (checking pressure switch, etc.)...and now I have to fix the cable coming from the alternator.  I noticed the cable had a small crack & when I touched it, the entire insulation just fell off.
 
So, it seems that age has done its damage & I agree it's looking to be a job to replace it...and since you're already there, I'd take a look at all the cables because they may look good, but might not be after all these years...
 
[sharedmedia=gallery:albums:369]

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[MLB]

If u make a replacement yourself, just match wire gauges.

Beware the 2 pin socket behind brake booster. I was able to painstakingly remove and re-use the round pins but only just. Touchy re-soldering job. Covered all with heat shrink, then wrapped it with foil heat tape.

Take your time and it should outlast you

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[MCL968]

John, let me know if you need a hand, I did the same thing to mine a few years ago. There is a file on here someplace that describes my process.

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[tejon007]

<p style="margin:0px 0px 11px;">Thanks Matt, I really appreciate your offer.<span style="margin:0px;">  </span>

<p style="margin:0px 0px 11px;">I’m sure I can handle it, but after a quick look at what’s involved, I’m not sure when I’ll get around to it.<span style="margin:0px;">  The job looks more difficult than easy & I’ll need to get some parts…  </span>

<p style="margin:0px 0px 11px;">I’ll also have to look around my garage storage because I have a couple spools with some 0 gauge stranded cable somewhere (red and black).<span style="margin:0px;">  Not sure if there’s enough left on the spools (I relocated the battery on my mid-engine car to the front a few years ago).</span>

<p style="margin:0px 0px 11px;"> So, it looks like everyone is saying that duct tape and zip ties aren’t the way to go?<span style="margin:0px;">  (but, it does look like zip ties are involved…yeah!)</span>

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[ds968]

Update : Interstate tested the battery, everything checked out OK. When I took it there it was 11.9 V. They charged for 24 hrs, and the. tested it the next day to see if it held the charge under load . It did . When I left the shop it was at 12.86 V. ( BTW, they said a new battery / fully charged one should NEVER be more than 13.1 , or , below 12.3 ..if either / or deviates from those numbers , there is a problem ).

Got home ten minutes later and tested my voltmeter to see if that instrument may be off : it read 12.80 , so close enough to the Interstate machine's volt reader . I left the battery out overnight , checked the voltage on the morning and it was 12.73. Put it back in the car ( all contacts and terminals cleaned thoroughly once again, and tightened as much as they would get ) and checked the voltage coming in when the engine was at idle - reading : 13.5 -13.6 . Revving it up above 4 K RPM, did not change the voltage much , still around 13.6 ( the people at Interstate said IF the voltage surges by more than 1 V or so at high RPM, vs. the idle reading , the regulator could be a problem allowing excess charge to come through ).

So we'll see what happens after I drive the car for a while , and if the terminals / connections still get very hot.

BTW, I was informed that even two or tree days without driving and just sitting outside in 100 + degree temps can cause the battery to lose power by at least half volt or even more , like a whole volt. Anyone in AZ who can confirm this allegation ?!

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[az968]

I would presume that 100+ in CA is the same as 100+ in AZ. Why are we always picked on :-)


When I used to live in 100+ in Phoenix, heat was always a battery killer. Leaving your car outside for a few days without starting and the voltage would drop too low. Don't know actual number but I wouldn't disagree with the Interstate comments.

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[ds968]

I would presume that 100+ in CA is the same as 100+ in AZ. Why are we always picked on :-).

True, it's just that CA gets those temps once every hundred years , and AZ gets them a hundred times a year . ;-) ;-) so you're " picked on " simply because you have more experience, and that's always a good thing, right ? ;-) :-)

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