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What amperage’s should I be seeing if I use a ammeter for the alternator?Thats not measuring alternator output, just static amp draw.
You need to unhook your alternator output and put a HIGH AMP ammeter between the wire and the output stud. DO NOT use your multimeter, they usually have a 10 amp fuse and you will blow that right away. That link that I put above is 60 amp and can go higher for short periods of time for diagnostic purposes. Just wire up some short leads so you can secure it to the output stud on one end and the output wire on the other. And obviously unhook the battery when your doing this as it'll be constant hot and tape up the leads well so when the engine is running they wont shake and spark on something.
I have owned the truck a year and only put 80 miles on it due to waiting on parts, fixing other things, and now what I have been stuck on is electrical. The previous owner had bought the truck and had it sit about 1 1/2 years. It has a 2021 inspection sticker. I have deleted 4 aftermarket front end leds that previous owner installed and wiring. I deleted a separate aftermarket switch he had installed for those lights. Deleted trailer break and all wiring. Deleted aftermarket tachometer and wire for that. Tried to get it back as stock as possible and in doing so I got everything to about 14.6 volts, beforehand when I bought the truck it would usually stay at about 11 or 12 and when I would turn accessories on it would often drop or even raise voltage. I do have a windshield brow with 4 running lights but I do not have it wired up. As to what I have done to the electrical system includes new positive and negative battery cables with the big 3 ground upgrade. Wired new dimmer switch. Fixed headlights through shorted and cut wires as before I had no running lights. New starter wires, new alternator wire, brand new alternator and battery. I have found multiple shorts and corroded wires that I have spliced mostly under the dash and on the motor. I believe the previous owner bought the truck and didn't know too much of what he was doing adding everything and maybe trying to fix electrical issues he had. Hope this helpsWelcome to the GMT400 forum! Always nice to have another enthusiast join the old truck cadre.
In order to get a better feel for what's going on, we need a little more detail about your electrical system.
Does your truck have only stock electrical loads, no options? Or are there one or more high wattage audio amps,
+ healthy bank of off-road Daylighters, etc? Aftermarket electric cooling fans? What is the state of your battery?
Will it pass a load test? Do you drive the truck every day, or is it mostly a weekend toy?
I've worked with high power electronics, and while troubleshooting wondered exactly what temp something that
was 'too hot to touch' would register on a thermometer? I would have guessed ~120° F, but according to NASA
the average is actually ~110-112° F. (NASA study for Astronauts)
I fully get that a healthy alternator working into a stock electrical load while cruising down the interstate on a 70° day
should be touchable. But I can easily see a healthy alternator working into high amperage aftermarket loads getting
hotter than I can touch yet still working within it's design limits. (They have to, underhood temps down south are
much higher than what we're talking about here.)
Let us know what kind of electrical setup you've got going on, and we can give you a better guess...
Also called "parasitic amperage draw or drain".Thats not measuring alternator output, just static amp draw.
Never disconnect the battery while the alternator is charging. It's dangerous, (the spark from disconnecting the battery terminals can ignite hydrogen gas produced by the battery) and it can destroy diodes in the alternator from the voltage spike as the current (amperage) is stopped suddenly....Just wire up some short leads so you can secure it to the output stud on one end and the output wire on the other. And obviously unhook the battery when your doing this...
^^^ Wisdom.The engine and other parts don't operate at comfortable temperature for you. They operate at what's normal for them.
What is the alternator rated for?What amperage’s should I be seeing if I use a ammeter for the alternator?
Never disconnect the battery while the alternator is charging. It's dangerous, (the spark from disconnecting the battery terminals can ignite hydrogen gas produced by the battery) and it can destroy diodes in the alternator from the voltage spike as the current (amperage) is stopped suddenly.
Also called "parasitic amperage draw or drain".
Never disconnect the battery while the alternator is charging. It's dangerous, (the spark from disconnecting the battery terminals can ignite hydrogen gas produced by the battery) and it can destroy diodes in the alternator from the voltage spike as the current (amperage) is stopped suddenly.
^^^ Wisdom.
I'm not saying there "can't" be something wrong causing the alternator to overheat. Just that it seems unlikely without other symptoms.
What is the alternator rated for?
Alternator is a standard AC Delco remy, not the heavy duty. Rated for 145 amps. Not sure if i bought one re manufactured or new.Also called "parasitic amperage draw or drain".
Never disconnect the battery while the alternator is charging. It's dangerous, (the spark from disconnecting the battery terminals can ignite hydrogen gas produced by the battery) and it can destroy diodes in the alternator from the voltage spike as the current (amperage) is stopped suddenly.
^^^ Wisdom.
I'm not saying there "can't" be something wrong causing the alternator to overheat. Just that it seems unlikely without other symptoms.
What is the alternator rated for?
I have owned the truck a year and only put 80 miles on it due to waiting on parts, fixing other things, and now what I have been stuck on is electrical. The previous owner had bought the truck and had it sit about 1 1/2 years. It has a 2021 inspection sticker. I have deleted 4 aftermarket front end leds that previous owner installed and wiring. I deleted a separate aftermarket switch he had installed for those lights. Deleted trailer break and all wiring. Deleted aftermarket tachometer and wire for that. Tried to get it back as stock as possible and in doing so I got everything to about 14.6 volts, beforehand when I bought the truck it would usually stay at about 11 or 12 and when I would turn accessories on it would often drop or even raise voltage. I do have a windshield brow with 4 running lights but I do not have it wired up. As to what I have done to the electrical system includes new positive and negative battery cables with the big 3 ground upgrade. Wired new dimmer switch. Fixed headlights through shorted and cut wires as before I had no running lights. New starter wires, new alternator wire, brand new alternator and battery. I have found multiple shorts and corroded wires that I have spliced mostly under the dash and on the motor. I believe the previous owner bought the truck and didn't know too much of what he was doing adding everything and maybe trying to fix electrical issues he had. Hope this helps