rcarlisle Posted August 13, 2021 Share Posted August 13, 2021 An '81 should have a 1G, which has an external fan and external regulator, which is the box on the fender by the starter relay. The 2G, aka Firestarter, came out in '86 and has an external fan but internal regulator - no box on the fender. The main problem with them is that the output connectors can develop a bad connection and start heating, which makes the connection worse, which causes more heating, which... The 3G came out in the 90's and has both an internal regulator and internal fans. It was a serious redesign and puts out more current at idle than either the 1G or 2G do at full tilt. Ok, looks like 1g in mine. Do I test the voltage in standard method - across the battery terminals with everything running? Link to comment Share on other sites More sharing options...
Gary Lewis Posted August 13, 2021 Share Posted August 13, 2021 Ok, looks like 1g in mine. Do I test the voltage in standard method - across the battery terminals with everything running? Yes, that's a good way to test. The 1G is adequate for a truck with standard options, inc A/C. But if you have the A/C and headlights on and the engine idling the alternator can't provide enough current to power them so the battery will make up the difference. That's fine unless you do extensive idling or add other power-hungry devices like a large stereo amp or electric cooling fans. Link to comment Share on other sites More sharing options...
rcarlisle Posted August 13, 2021 Share Posted August 13, 2021 Yes, that's a good way to test. The 1G is adequate for a truck with standard options, inc A/C. But if you have the A/C and headlights on and the engine idling the alternator can't provide enough current to power them so the battery will make up the difference. That's fine unless you do extensive idling or add other power-hungry devices like a large stereo amp or electric cooling fans. I'm old enough to remember when ALL vehicles did these gyrations of lights dimming, slow signals, etc, depending on engine speed. At least the truck has a big enough battery to not panic when you listen to the radio with the truck off. Back in the day we did that a lot - wash the car with stereo blasting with windows up. My new car gets in a panic if I try to listen to radio with car off - gives me constant WARNING messages. Usually when the sun goes down, it starts getting cool enough for windows down. My preferred way of travel. Link to comment Share on other sites More sharing options...
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