Hey guys!..So proud 4 year owner of an 84 f150, powered by a granny gear 4 speed and a 300 straight 6..She's certainly given me a ton of fun problems over the years, but this ones got me unsure, so hopefully you can assist!

Anyways so here's what's going on..recently I had a dead battery since she was off the road for a couple months..I charged up the battery and took her to get tested...battery came back 110% perfect, but results for the alternator not so much..so I listened and replaced the alternator. While I was at it I tossed in a new voltage regulator, since mine looked ancient. Battery is still perfect..although my previous issue still isn't fixed. Even before and still after the new alternator/regulator my gauge lights get much brighter and flicker when I hold the throttle at a higher rpm than idle and my charge gauge will rapidly shake from the the middle to about 3/4ths towards full.

Any info will be very greatly appreciated..im thinking instrument cluster regulator? Time to print out some wiring diagrams and hope for the best

 

Factory gauges are typically junk, I'd double check it with a voltmeter. Headlights always brighten with higher engine speed and dim under load of other electrical items, even new cars experience this. If its extra noticeable though that's not necessarily normal. The alternators on these older trucks are typically underpowered. If your battery isn't dying then I'm not sure why you think there's a problem, but if the dimming bothers you... I don't know what you replaced it with, but consider the 3g alternator upgrade. If you don't know what that is, google away there's tons of info.