Alternator???

[Hydro-idi]

Hey guys as stated below, I got an 87 pickup that has the stock alternator I believe. I was wondering if anybody knew what the stock alternator amperage is for my truck or if its hidden somewhere on the housing??? When a/c and hydro injection is off, I see 15-16 on the volt gauge. And when I got the a/c blowing and hydro on, it almost touches red on gauge (roughly 10-12 volts). Does this mean I'm about due for a bigger and/or new alternator??? Any advice would be appreciated as always!

 

[8973]

I've heard the voltage regulator and/or harness plug is a fairly common issue. I need to check mine soon.

Anybody want to chime in with some trouble shooting tips?

 

[Hydro-idi]

Oh and also...when I turn off the hydro injection it doesn't seem to help gain much volts fyi for anybody wondering about that. And I just checked the volt regulator and it is the old original. Harness plugs seem to be okay. Would be nice if the volt regulator was the problem because that's cheap! Let us know guys

 

[OLDBULL8]

Prolly 95 to 100 amps. Voltage is dependent on amprage draw and condition of batteries. Normally the charging voltage runs about 15 to 15.2 after a start then reduces to 13 to 13.2 . With A/C on alone, amperage draw is about 10 to 12 amps. Charging voltage/amperage is dependant on engine RPM. The stock alternator only puts out about 10 amps at idle and full output at 3000 RPM. A true voltage gage will tell you what the alternator is doing. If you go to a larger alternator the wireing size has to be increased.

 

[Hydro-idi]

Okay thank you for the information.

 

[91idi]

With your electrical demands, this may be a good read for you ... http://www.oilburners.net/forums/showthread.php?14573-130-amp-3G-alternator-install