charging system?

[CreepyCrawler]

ive got a 91 ranger 4.0 4wd i use as a daily driver its pretty much bone stock. recently when idling the charging gauge at idle jumps back and for between 12 and 18. it only does this at idle.

any thoughts?

also im thinking about upgrading to a higher amp alt. whats the most effective alt i can get for a decent price or swap?

 

[RonD]

I would give the wiring and battery ground a "once over", vibration at idle can show loose or marginal connections.
Light Green/Red wire on alternator comes from the charge gauge, that connector or the wire could be loose.

Good read here about installing a 130amp: http://www.therangerstation.com/tech_library/130_amp_alternator_install.shtml

 

[CreepyCrawler]

thanks bud