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Engine Compartment Positive Post Very Hot To Touch

After running my '84 and attempting to hook up the battery tender to the positive post in the engine compartment, I noticed it was way too hot to touch. I never noticed this before and waited for everything to cool down before hooking up the tender. Touching the terminal with the tender hooked up it feels of normal temperature. Was the post hot just from absorption of engine heat or is there an issue here?
Old 01-14-2018, 11:07 AM
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Could Be - Definite Maybe

Hey Gab - There are other members with lots more experience who will probably think of more suggestions, But 1st - Have you had any previous charging issues ? Electrical problems can generate lots of "It Could Be and Definite Maybe" discussions but a hot spot in a circuit is typically caused by one of the following basic reasons :

1) High Localized Contact Resistance, 2) Higher Than Normal Voltage or 3) Higher Than Normal Current (Electrical Load).

High Contact Resistance can be from - Over Heated, Dirty, Contaminated or Loose Wiring Connections and/or Poorly Crimped Terminal Lugs.

High Voltage = Voltage Regulator Malfunction. This can be easily verified using a Volt Meter and is rarely the direct cause of a hot spot issue.

High Current can be from - Heavy Electrical Load (Examples - From Failing/Internally Shorted Battery, Failing Ignition Control Unit, Failing Starter (Bendix is Not Disengaging ?), Perhaps from an Insulation Failure or Some Exposed B+ Wiring that's Touching Ground.

For the Overall Best Long Term Results also clean and tighten the terminal lugs at the Alternator B+ Output Terminal/Jumper Post/All the Wires going to and from the Pos Battery Post. Also Inspect the Ground or Return wiring - Neg side of the charging circuitry. Both ends of the Neg Battery Cable, Engine to Frame Grd Cable, Several smaller Grd Terminal Lugs above fuse panel, etc.... Reseat all the relays and inspect the relay legs and sockets for corrosion.

Keep Us Posted and Good Luck, Michael
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Old 01-14-2018, 05:03 PM
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Its hot under the hood, and some heat soak could occur (when you turn off the motor and the fan stops), but the test I think would be how hot is it compared to other nearby bits?

Do you have a cover on the jump post?
Do you have the plastic bit that clips to the fender and keeps water off the 14 pin and jump post?
Old 01-14-2018, 11:46 PM
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remove the hot post with an 11mm wrench,
clean the connectors with some scotchbrite, add some Deoxit 100 and put it back together
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Old 01-15-2018, 06:08 AM
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Thank you for the responses!

The positive terminal does have its plastic covers on. I took everything apart and cleaned it then applied Deoxit but that was a year ago. I'll reinspect it, take voltage readings, compare temp with engine and positive terminal for any differences, and check out the actual battery terminals too. I haven't checked the battery in a long while due to its inconvenient location but will. Been using the engine compartment terminal for hooking up the battery tender, easy to be lulled into complacency and not checking the physical battery itself. Might be horrified in finding something when I do.

Last edited by GabrielS; 01-16-2018 at 09:59 AM..
Old 01-16-2018, 09:52 AM
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You might also check the NEGATIVE flat braided battery cable which is known to fail.
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Old 01-17-2018, 03:57 AM
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Battery Maintenance -

Hey Gab - I don't know if your battery would be all your problem but it's "out of sight - out of mind" location in the 928 often causes us to neglect the needed routine maintenance. I try to check mine over every couple of months especially in the summer. A friend ruined his battery by not checking the water level for almost two years. Since it seemed to be starting fine - it was assumed to be OK until it wasn't.

Good Luck - Michael
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Old 01-17-2018, 07:30 AM
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Quote:
Originally Posted by JK McDonald View Post
Hey Gab - I don't know if your battery would be all your problem but it's "out of sight - out of mind" location in the 928 often causes us to neglect the needed routine maintenance. I try to check mine over every couple of months especially in the summer. A friend ruined his battery by not checking the water level for almost two years. Since it seemed to be starting fine - it was assumed to be OK until it wasn't.

Good Luck - Michael
I can't remember the last time I ever added water to a battery, not for many years. I think these newer batteries are quite different from years ago. If you want to be safe, replace the battery every four years.
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1986 928S
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Previously owned: 67 Vette, 427 L88 Stingray, 74 De Tomaso Pantera L
Old 01-18-2018, 08:30 AM
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Ol' Blue -

Hey Harborman - I think you are right when it comes to normally not having to add water to a late model battery with a healthy charging system. I've always been a bit on the cautious side when it comes to the maintenance of all my cars. It's not that I expect there will be a problem when I check the oil, tire air pressure or water level in the battery. I was just suggesting that Gab eliminate the easy stuff so it is not (potentially) part of his electrical malfunction. Like has already been mentioned, just from reading his initial write-up, it sounds like cleaning up the jumper post connections may solve the issue ?

Most of the cars and motorcycles I own and enjoy are considered orphans by most people because they are too temperamental, too expensive or too much trouble to keep on the road. A perfect example is my 1972 Volkswagen Bus "Ol' Blue" which because it has difficulty getting out of his own way, has a bumper sticker that says "Don't Honk - Push".

Michael
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1986 930 - "Well Hung"
Old 01-18-2018, 02:17 PM
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Quote:
Originally Posted by JK McDonald View Post
Hey Harborman - I think you are right when it comes to normally not having to add water to a late model battery with a healthy charging system. I've always been a bit on the cautious side when it comes to the maintenance of all my cars. It's not that I expect there will be a problem when I check the oil, tire air pressure or water level in the battery. I was just suggesting that Gab eliminate the easy stuff so it is not (potentially) part of his electrical malfunction. Like has already been mentioned, just from reading his initial write-up, it sounds like cleaning up the jumper post connections may solve the issue ?

Most of the cars and motorcycles I own and enjoy are considered orphans by most people because they are too temperamental, too expensive or too much trouble to keep on the road. A perfect example is my 1972 Volkswagen Bus "Ol' Blue" which because it has difficulty getting out of his own way, has a bumper sticker that says "Don't Honk - Push".

Michael
Hi, Just wondering if your VW Bus has flowers and peace signs painted on the sides.

Yes, I think a good cleaning of the battery connections and cables might solve his problems. I did that on my 928, but later found the negative battery cable was bad internally but looked fine on the outside. I pried open the crimped connection and dust came out!
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1986 928S
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Old 01-19-2018, 04:23 AM
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Quote:
Most of the cars and motorcycles I own and enjoy are considered orphans by most people because they are too temperamental, too expensive or too much trouble to keep on the road.
Still have your CXTs?
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Old 01-19-2018, 06:16 PM
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Hot Jumper Post -

Hey 19psi - My trailer has always been an orphan magnet when it comes to dead-in-the-water projects. I tell the wife that they just climb aboard. I took the CX650 Turbo out for some air the other day to stretch his legs and just as I was pulling it back down off the highway a state trooper was behind me with his lights on. After talking bikes for a few minutes he gave me a warning for not signaling a lane change somewhere. Not sure where I picked him up but was expecting "much" worse.


Gab - how is your electrical troubleshooting going ?

Michael
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Last edited by JK McDonald; 01-21-2018 at 11:21 AM..
Old 01-21-2018, 08:20 AM
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Hi Michael!
Thank you for your concern. I Finally got around to inspecting the battery after removing all the paraphernalia on top (can't see changing a tire on a lonely country road in the dark being much fun with removing all these obstacles!). Checking the battery, all seemed well, no corrosion, voltage as it should be. When running the engine without accessories on, the positive terminal in the engine compartment felt normal to the touch. The a/c was switched on and that caused it to heat up I imagine due to the draw in amperage. Turning the a/c off resulted in the terminal returning to engine compartment temperature. I can only surmise this is normal and is of no concern...or is it?
Regards,
Gabriel

Last edited by GabrielS; 02-04-2018 at 07:39 PM..
Old 02-04-2018, 07:31 PM
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Please tell me what happened after following the advice in post 4?

The reason electrical connections heat up is because they have poor electrical connectivity.
Since you verified this connection is heating up when a bigger load is put on it ,
then your next step should be to clean the connection.
Then test it,

NOTE since you did this step last year it suggests its time to do some servicing of the connection.
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Old 02-05-2018, 03:52 AM
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I'll do that as it's been over a year since I've looked at it. It's on my list of 'to do' with the 928 along with my Mazda Rx-7 and VW Golf!

Last edited by GabrielS; 02-06-2018 at 08:19 PM..
Old 02-06-2018, 08:14 PM
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Its nice to get a response from someone thats asking for advice,
goodluck with your garage full of machines
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1988 S4 5 sp, Black / Black leather/ Carmel carpet
Old 02-08-2018, 03:52 AM
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Quote:
Originally Posted by Mrmerlin View Post
Its nice to get a response from someone thats asking for advice,
goodluck with your garage full of machines
Thank you! I'll keep you posted when I do the procedure which may be a while. Perhaps my findings may help others resolve a similar issue.
Old 02-10-2018, 09:18 AM
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Checked the connections and all seems normal with no signs of corrosion or wire being disconnected. The post feels normal until the a/c is turned on that's when it becomes uncomfortable to touch. I'm assuming at this point it's due to the extra load being placed on the charging circuit and is normal though concerning.
I think I'll also check electrical connections to the a/c compressor, climate control switch on the dash and any other electrically associated switches or connections just to be sure there's nothing questionable going on.

Last edited by GabrielS; 03-21-2018 at 07:38 PM..
Old 03-15-2018, 10:14 AM
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Hot electrical connections are not normal, or something to let go. Check the AC related wiring more carefully.
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Old 04-05-2018, 07:41 AM
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