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Alternator is getting very hot

  
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Alternator is getting very hot

 
Richz28 Richz28
New User | Posts: 39 | Joined: 09/09
Posted: 01/29/11
02:12 PM

I have a 1969 camaro with a 454 BB.

the battery is in the trunk and the alternator is a 100amp 1 wire.
the main battery cabel is hooked up to the starter and runs to the battery.

I have a 10 guage wire that comes off the starter to a post that runs the fuse box - Fans and msd box.

the alternator gets so hot to the point you can't touch it because it will burn your hand.

This is the third alternator as this has burned out the other 2.

any help would be great

Thanks  

TheSilverBuick TheSilverBuick
Guru | Posts: 1227 | Joined: 02/06
Posted: 01/29/11
02:40 PM

Alternators are usually mounted up against an exhaust port on the head, it's not uncommon for the case to get too hot to touch.  

If it's a powermaster, I've never heard of them being reliable.  
-
The Silver Buick- '77 Skylark coupe w/ a Fuel Injected Buick 455&TKO-600, '72 Centurion Conv't - 455w/TH400, '67 T-bird 4Dr (suicide) w/428&C6. '69 Firebird replaced!

http://www.bangshift.com/forum/index.php?topic=6189.0

Ron1973 Ron1973
Enthusiast | Posts: 629 | Joined: 09/10
Posted: 01/29/11
02:43 PM

more of a question then answer but with the battery in the trunk, without a good ground to the body/frame cause this maybe?  
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Ron1973

Richz28 Richz28
New User | Posts: 39 | Joined: 09/09
Posted: 01/29/11
02:53 PM

So the alternator getting that hot wont hurt it or burn it out faster?

and yes its a powermaster heh.  

waynep7122 waynep7122
Enthusiast | Posts: 594 | Joined: 08/09
Posted: 01/30/11
12:34 AM

10 gauge is a bit thin for a 100 amp alternator...

proper crimp terminal can be had for 8 and 6 gauge wires....

i just picked up a 135 amp delco at the junk yard.. it has a 6 gauge wire on the output... and a 8 mm stud..

a ground wire is a good idea also...

do you have a hand held digital volt meter????

can you do a few tests... takes about 5 minutes... with the engine running...

set your digital volt meter to 20 volts DC scale...    start the engine and turn on the headlights...  

1..   measure the positive battery post to the negative post..    14.1 to 14.7 volts...

2..   measure from the negative battery post to the body...      0.02 to 0.04 volts... this is a rear mounted battery..

3..  measure from the negative battery post...   to the engine if you have long enough test leads...   0.04 is an expected reading..  but with a trunk mounted battery..  you might get a little more... but under 0.10..

4..  measure from the alternator output terminal to the starter top post or terminal block where the battery wires go to the back of the car...    again.. 0.04 is a good reading..

5... measure from the engine block to the body/firewall...    0.02 is expected.. but you might find 0.04..

6... measure from the alternator rear case. to the body...     0.02 to 0.04 is expected...

why such little voltage readings..   if the grounds are good...   you will get these tiny readings...

if the grounds are bad.. or the positive side has bad connections.. there will be a difference in voltage between the parts.. or a difference in ground voltage levels between parts...

since electrons flow from negative to positive...   everything needs to be properly grounded with thick enough wires to handle the load...   a digital volt meter can measure the difference in voltages when there is a load or current flowing through the circuit...  but this only works when there is a load or current flowing...

so the alternator is putting out electrons through the case.. pushing them toward the battery negative..  the completed circuit is on the positive side... both sides need to have equal wire sized to carry the amp load...

why...

think of a kink in a fuel line as corrosion or resistance in an electrical circuit...     think of the flow...   with a kink in the line...  if the engine is off.. and the electric fuel pump is running..  the kink is not enough to block all the flow... so the fuel pressure looks good...    now.. measure the fuel pressure during a burn out..   when you need max flow..  there is pressure behind the kink.. but the kink in the line is restricting the flow..  so little will be getting through..  this will show up as reduced pressure...  

so.. when the car is running and the headlights are on..   if there is resistance .. there will not be enough electrons to power the circuit...    this will show up with a volt meter when the circuit is active with a load taking electrons and using them.. as a measurable voltage...  these are called voltage drop tests...  

waynep7122 waynep7122
Enthusiast | Posts: 594 | Joined: 08/09
Posted: 01/30/11
12:50 AM

post what you find in the way of the numbered tests above.. it only takes a few minutes and will find all kinds of amc gremlins..

grounds are so important.. that racers have started running a ground wire between each head and the distributer housing... this shortens the high voltage spark circuit length...

with a normal build...  the spark circuit is... coil.. coil wire.. distributer cap... rotor  jump a gap.. distributer cap again..  spark plug wire.. spark plug.. jump the gap.. through the head.. to the intake to the distributer hold down clamp to the distributer housing...

with the ground wire from each head to the distributer housing..  the route is far shorter.. and any sealer on the bolts or studs will not reduce the continuity..  

your heat build up in the alternator could be from the alternator trying to push current out to charge the battery..  but running into resistance..  


i have heard talk .. of racers... running a cranking battery in the rear...   one of the tiny circle track batteries up front.. with big caps set up on the output to the ignition box... this increases the instant current to the ignition box..  remember.. batteries are chemical reactions.. they take time to start flowing current..   capacitors are instant discharge storage devices... talk to somebody with a really powerful amp.. you will see big caps as close to the amp as possible..  this feeds the amp with instant current..  but i have gotten off thread...  

Ron1973 Ron1973
Enthusiast | Posts: 629 | Joined: 09/10
Posted: 01/30/11
07:40 AM

Icon QuoteRichz28:
So the alternator getting that hot wont hurt it or burn it out faster?

and yes its a powermaster heh.


I think its reasonable to say yes it will hurt it, this is your 3rd one?
and heating hot enough you cant touch it would burn out faster.  
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Ron1973

Richz28 Richz28
New User | Posts: 39 | Joined: 09/09
Posted: 01/30/11
02:19 PM

well I did what you asked and got some interesting readings.

1 positive battery post to negative post was the 13.9-14.3ish

2 negative post to frame i got a zero reading....

3 measure from negaive battery post to engine i couldn't do i don't have long enough leads.

4 alternator output terminal to starter top was 14.1

5 engine block to firewall was 0.05

6 alternator rear case to body was 0.05 also

i went from alternator post to the spot i have teh 10guage wire breaking off starter to the post that has everything else running to and it was 14.1ish  

skyeking skyeking
User | Posts: 243 | Joined: 11/09
Posted: 01/30/11
04:31 PM

Laugh  Hi there,
   To be brief,
  [1] I had a zillion nightmares with this crap and it was all so positely simple
      to alleviate the problems.Numero uno..BUY a GOOD Alternator with ***
  [2]  I use[d] Bosch alternators for 10 years and get about 5/6 years trouble
       free usage. Yes, use every earth strap as recommended and more if possible.
       The best insurance of earthing the alternator is to run a 6mm cable from
       the battery to the body of the Alternator if your car is a negative earth.
        Good luck and remember this...Nothing succeeds like success.Skyeking :cool  
skyeking

waynep7122 waynep7122
Enthusiast | Posts: 594 | Joined: 08/09
Posted: 01/30/11
08:35 PM

Icon QuoteRichz28:
well I did what you asked and got some interesting readings.

1 positive battery post to negative post was the 13.9-14.3ish

2 negative post to frame i got a zero reading....

3 measure from negaive battery post to engine i couldn't do i don't have long enough leads.

4 alternator output terminal to starter top was 14.1

5 engine block to firewall was 0.05

6 alternator rear case to body was 0.05 also

i went from alternator post to the spot i have teh 10guage wire breaking off starter to the post that has everything else running to and it was 14.1ish


perhaps... you are going to have to go to a increased amp alternator... so it does not have to work close to the max current...

are you aware that for many alternators like delcos...  that rectifier bridges can be had with double amp rating...

many rebuilt alternators.. come with  6 .. 25 amp, 100 PIV diodes...   piv is peak inverse volts...

there are heavy duty rectifier bridges that have 6, 50 amp, 200 PIV diodes...  they cost a few bucks more..

there are suppliers that wind custom rotors and stator windings...    that can be used up to 200 amps for arc welding...    and increased amp rating for the voltage regulators...

what did you do with the burned out units that you have?????  still have them.. or trade them in?????

if you still have them..    how about cracking one open.. taking out the stator .. OHMing the diode trio...  see if when the digital volt meter is in diode test..  that each lead only tests ONE direct.. and open the other..

same thing with the rectifier bridge...   each diode can only show continuity in one direction..  find one that does not show in either.. you have found the bad diode..     internal voltage regulators are harder to test..

and the ONE wire or self energizing ones have a slightly different test...

one more thing..   if somebody shuts off the battery shut off switch.. while the engine is running.. the alternator will last about 0.25 seconds..  a quarter second..  as the output current flow has just lost its load.. for that quarter second until the voltage regulator can reduce the power to the rotor which reduces the magnetic field... the current will build up as voltage... this can take the instant power well over 100 volts...  enough to damage electronics in the car...   enough to let the smoke out of the alternator diodes..


i would like you if you can.. redo test number 2...  and explain where you are testing exactly...  the 0,05 is an expected reading...  when you end up with a 0.00 reading.. either the wires are very short.. or there is no ground load attached to that part...

i did make a mistake in typing..    test number 4 should have been from the alternator output terminal... to the starter solenoid top terminal.. or to where the 10 gauge wire attaches to the main battery supply cable..

this last test needs to be done with as many things running as possible..  headlights.. radiator fans.. engine..

or just switch this to a properly made 6 or 8 gauge wire...   yes i know its a problem as your harness is complete..  probably properly wrapped...    depending upon your voltage drop reading on that circuit..

check out the bottom of page 18 for the heavy duty rectifiers...

http://www.wagneralt.com/catalog/books/W2008-06.pdf  

Richz28 Richz28
New User | Posts: 39 | Joined: 09/09
Posted: 01/30/11
09:18 PM

I don't have the old ones I had to turn them in.

On number 2 I did go from the alternator post to the starter post and I got 14.1. than I went from the starter to where I have the 10guage wire running off to the side and that was also 14.1

I can wait till this one burns out it has Lasted the longest so far. The First one was about a year old and the 2nd one was 2 months at most and this one I have no is going on 1 year.

so when this one goes out I will buy a better brand.

I am just worried the Hot alternator is going to start a fire but I checked the alternator on my truck and it was pretty damn hot.

The car doesn't run many things.

Fuel pump
dual Fans
All lights - No dash Lights
Tach-oil presh guage- temp guage (lights)
Msd box. AL6

Thanks for your greats posts btw I have learned allot with that link.  

TheSilverBuick TheSilverBuick
Guru | Posts: 1227 | Joined: 02/06
Posted: 01/31/11
08:10 AM

I personally wouldn't buy a powermaster. My understanding of them is they pretty much take a standard 60-65amp GM alternator and change out the rectifier and diodes to make it a one wire and increase amperage. Modern 100+ amp alternators have more windings in them to generate more amperage. Running more amps through fewer windings is going generate more resistance heat and be harder on the brushes, diodes, and recifier.  
-
The Silver Buick- '77 Skylark coupe w/ a Fuel Injected Buick 455&TKO-600, '72 Centurion Conv't - 455w/TH400, '67 T-bird 4Dr (suicide) w/428&C6. '69 Firebird replaced!

http://www.bangshift.com/forum/index.php?topic=6189.0