1993 Cobra alternator problems

enblethen wrote:
There is two battery systems. One is the chassis, normally a 12 volt. There is a second battery system that may use 12 volt battery(ies) or two 6 volt batteries wired in series.
The chassis battery ground connection goes to the frame or engine block.
If there is resistance between these two systems it can add load to the alternator. This can be read with multimeter. Check for resistance between the negative battery of each. This should be Zero ohms. Then switch to a low DC volt scale to see if there is any current showing. There should be no voltage.
A 1993 should have a sepertine belt. It is tightened by slip bolt on alternator. It is hard to get tight. I use a crow bar through the bracket. It needs to be tight!
Condenser fan? I believe that is a radiator fan. It should not run all the time.

time2roll wrote:
Dual output alternator rebuild thread

jyrostng wrote:
The biggest load I think you would see is with the dash AC on,(the fan) and the electric condenser fans on in front of the radiator. Both on with the ac clutch might be over 50 amps. The fuel pump inside the gas tank, ignition, lighting, radio, wipers, dash lights. That puts a lot of load on that small alternator pulley with maintain the batteries too. The way to actually see if the belt is slipping on the alternator, see if that pulley will boil spit. It gets really hot when it slips. Check it right after you shut the motor off. if it was hot, you may have to change that serpentine belt, likely it's cracked and dried out. My 89 had the curved bracket with a slot the alternator bolt used to adjust the belt, I used a 2' long 3/8 extension to pry the belt tight. Since yours doesn't have smog pump, don't really worry about the belt being too tight. Just tight enough to prevent any slipping. if it had a smog pump in line driven by that belt, you would have to be more careful about the tension.

femailyetti wrote:
my old 86 P30 with a 454 has a duel output alternator, on terminal controls the start motor, and one terminal goes to the house batteries, some one had tried to replace it with a single output model, it would never work correctly, and eat alternators. I believe yours is to new to have this type of alternator. You might want to check if you purchased it used. I had some other fun because of things that were done by owners trying to fix things with what the parts guy said was the right part.

jyrostng wrote:
I suspect the belt is slipping, esp. when the fan kicks in. does this 454 have a tensioner pulley or is the belt mechanically adjusted?

MrWizard wrote:
I have (3) suggestions
1. check the grounds and check that fan wiring, perhaps the main power for the fan is not connected to right spot, sounds like somebody connected it to field wire for the alternator

2. fine a Hot Rod after market car parts seller, and get a new alternator that has high amps at low rpm, the one i bought for the Pace arrow on P30, was about $200
much better alternator than the ones from the car parts store

3. is more about use
does he like to dry camp ? does he spend several days or more in one place, then get up early and take off driving ?

i suggest a slight change of routine
let the engine idle for 30 minutes before leaving
or run generator for (1) hour before leaving

stock alternators, have a hard time, dumping max load amps into batteries for more than a few minutes

getting on the road at 60mph with low batteries really taxes the stock version of these delco alternators,
the stock versions are only good for about 60 percent continuous load
which takes care of ignition, heater a/c fans and lights
but over works them trying to charge (3) or more batteries that are low