Thread: I thought my alt. was going bad.

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I have been looking at getting a new alt since this one seemed to be dropping voltage pretty quick. Well I was doing some work on the engine getting it ready for the summer , you know replacing hoses and the belt. While replacing the belt I noticed that the idler pulley was tight (89 TBI)and looking a little closer I could see where things where starting to heat up ,the pulley was starting to deform. Replaced the pulley and things are back to normal, well sort of......


The volt meter on the dash shows to be charging at more than 13.5 volts when I first turn on the truck. After the truck has been on for a while it shows to be charging as low as 12 volts. The thing is that I hooked up my volt meter to the battery and then to the alt. and they both show to be chargeing at 13.5-13.90 the entire time which I think is fine. I guess its time for a new dash gauge.

Typical factory voltmeter. My '97 does the same thing. You can count on it to indicate if the alternator is completely dead and not much else.

Kitz

I got one of those guessamatic voltmeters too. Less accurate than my ammeter, but safer.

My 97 did/does the same thing as well, BUT, I have noticed that sometimes it stayed running low. I also noticed that when it stayed running low, if I popped the hood and grabbed the hot lead, it was always loose!! Side mount cable and the way it hangs/lays coming off the battery, no matter how tight I got it, within a couple of weeks it would be loose again. I ended up stripping the threads out of a fairly new battery, so I switched the hot cable to a top post end and haven't had it run low for quite sometime...might check that on yours...Donny