to much stuff for the alt

[buffblazer]

from my earlier thread about the charging issue. i put a really cheap alt on just to temp get the truck running and im noticing that its charging fine, but if i turn on my headlights and then my heater, my idiot light barely turns red, almost impossible to see.

then i turn on my aux lights and it off course gets brighter.

i noticed with my head lights on and heater, im making 30 amps. then the gauge pegs past 60 amps when the other lights are on also.

plus i have MSD dizzy and Box, i noticed that under full throttle it sputters a little when the secondarys open, then clears out.

could this new alt be so week (65 amp) that it just cant keep up with the truck?

 

[K85 Octane]

how old is the alt? Might be other things at work here too, but really, how nice would it be to have a new 140amp alt anyway. Just takes gettin out the ol' credit card.

 

[ChrisPerry]

from my earlier thread about the charging issue. i put a really cheap alt on just to temp get the truck running and im noticing that its charging fine, but if i turn on my headlights and then my heater, my idiot light barely turns red, almost impossible to see.

then i turn on my aux lights and it off course gets brighter.

i noticed with my head lights on and heater, im making 30 amps. then the gauge pegs past 60 amps when the other lights are on also.

plus i have MSD dizzy and Box, i noticed that under full throttle it sputters a little when the secondarys open, then clears out.

could this new alt be so week (65 amp) that it just cant keep up with the truck?

Yes, it could be that with all of the draws it can't keep up. I think you need an alternator that can put out @ least 30% more amperage than your accessories can pull.

 

[ChrisPerry]

charging wire

How big is the wire that goes from the alt. to the power block on the firewall? Does it have a 2nd one that goes directly to the battery?

 

[sweetk30]

i had a 105 amp stocker on my 350 and with wipers / heater / full light bar on top for caution use plowing snow and truck its self tbi injection i was watching my batt volts drop after 30 min of plowing.

mind you i run live hydro plow non electric and also 1000ca battery . my federal signal street hawk lightbar all light option will draw 60-70 amps give or take alone on full .

i jumped to a 200 amp alt and its 125 @800 rpm also if need be i now have ZERO problems .

all your stuff on 65 amp is way to much draw.

 

[shady]

Its your battery most likely. If the alt is new and your having issues with not enough for everything your batt is going bad. put one in from another vehicle and see if it still does it. Had it happen to me and we just recently found the same prob on one of our work trucks. Starts and runs fine but it was still the prob

 

[Safari-K5]

A lot of the older alternators are only rated at 70 ish amps. even a brand new alt might not be enough for what you are running. I would take the advice of ChrisPerry Do the big 3 wiring upgrade. get a higher amp 150 ish alt and check your battery.

Most people dont realise how much more electrical load we put on 12v systems now days same reason you will see things switching to the new 42 volt standard in a few years.

 

[buffblazer]

What gauge wire should the charge back wire be?

 

[82TexasBurban]

With all that stuff the alternator can't keep up. I switched to a 93 0r 95 amp alternator designated for an 86 K10. I swapped the pulleys from the old one and placed it on the new one and it works much better than the 63 amp one that was on there. it runs everything except when I crank the heater on high with lights radio etc everything on. When heater is blowing on high it will start to decline. So yeah...a better alt will help. With extra lighting I would not go with less than a 120 or 140.

Check the alt wire as well. It won't fix the low amp output but it will assist with consistency. Check the connections, and all wiring to and from. If it is old or burned or wires are showing replace it with new wire. If budget does not allow wait and save and limp till then. It's worth adding new wires with a new alt.

 

[ChrisPerry]

What gauge wire should the charge back wire be?

I think factory is 8 gauge. I would go to 4 gauge then you could upgrade to up to 180 amp alternator and as long as the charging wire isn't over 15' long you wont have any problems.