Riddle me this batman.
I installed a voltmeter in my cab so I could monitor that like any other gauge. Last week while driving I noticed it was at 12V, shrugged it off and hoped it would fix itself. It did... for a little while. Over the past week every now and then after a bit of driving it stops charging. Went to work yesterday morning, 13.6V. Drove to the store after work, 13.6V. Store to home, 12V. Came home, let the truck sit half an hour, started up, 12V. This morning, 13.6V, sitting at a light idling with headlights, hvac blower and rear defrost on, 12V. Rev up the motor and it goes back to 13.4ish. Start driving and it goes to 13.6V (I've always seen this truck dip down to low voltage at idle with a couple things on). Also, the thing emits this high pitched, barely audible CRT TV like hum even with the engine is off.
I checked all the wiring yesterday after work and everything seemed fine. Everything is pointing to the alternator to me- its some US Industries brand parts store special, replaced another identical one under warranty a little over a year ago bc that one shorted out on me, literally zapped me and died. That one came with the truck installed by the PO and he gave me the receipt showing it was only a few weeks old. Just wanted to make sure I'm not missing some mystical Lucas part in the middle.
I installed a voltmeter in my cab so I could monitor that like any other gauge. Last week while driving I noticed it was at 12V, shrugged it off and hoped it would fix itself. It did... for a little while. Over the past week every now and then after a bit of driving it stops charging. Went to work yesterday morning, 13.6V. Drove to the store after work, 13.6V. Store to home, 12V. Came home, let the truck sit half an hour, started up, 12V. This morning, 13.6V, sitting at a light idling with headlights, hvac blower and rear defrost on, 12V. Rev up the motor and it goes back to 13.4ish. Start driving and it goes to 13.6V (I've always seen this truck dip down to low voltage at idle with a couple things on). Also, the thing emits this high pitched, barely audible CRT TV like hum even with the engine is off.
I checked all the wiring yesterday after work and everything seemed fine. Everything is pointing to the alternator to me- its some US Industries brand parts store special, replaced another identical one under warranty a little over a year ago bc that one shorted out on me, literally zapped me and died. That one came with the truck installed by the PO and he gave me the receipt showing it was only a few weeks old. Just wanted to make sure I'm not missing some mystical Lucas part in the middle.