Changed A/C compressor and clutch. Now truck is putting out 12.6 Volt out of Alternator. Replaced alternator and still getting 12.6 volts. What could cause this?

Sounds like your still running power thru the original regulator also. Disconnect the original system completely so that your running power directly from alternator's inboard regulator and to the battery. Nowhere else.

power to alternator goes direct from battery (usually through fuse able link) trace that power wire from back of alternator to the battery see at what point the power is on that is the place to look for

to that have DVOM at dc volt,put the black lid at battery ground and the red one ,on wire from back of alternator,keep following to the battery,till you see 12 volt on your volt meter,

If you rev the engine with the voltmeter attached to the battery the voltage should rise to over 12 volts if the alternator is working.

to change the points to electronic you will need to get the manufacturer of the distributor and contact them for a compatible electronic kit to replace the points or replacement distributor
to fit an alternator , get one with an internal voltage regulator ( talk with an auto electrician for the best unit --it is not necessary to go big amperage units so one about 35-60 amps will suffice and cheaper as well)
wiring will be the same as will fuses (neither volt sensitive)
gauges will have to be changed to 12 volt units
bulbs changed from 6 volt to 12 bulbs and switches will be the same as they are no volt sensitive
basically the same circuit can be used and the only place to be careful is the alternator wire to the battery and the charge light or volt gauge ( auto electrician can advise here )
starter motor will have to be changed to 12 volts and you will again have to get the replacement unit from an auto electrician as the bendix pitch , movement and mounting neck will be critical
wisconsin did not make electrical components but used off the shelf companies such as delco remy, lucas , bosch, ac etc for the accessories to the engine
it is an interesting project so collect as much information from auto electricians and web sites to help you

Hello,
When you say battery voltage how are you testing it? Are you looking at a gauge on the dash? Or are you physically testing it with a multi meter? If the truck is dying and you recently replaced the alternator and battery I would first suggest you to check all them connections again real good. Snug them all up. Check for corrosion and clean as needed. Did you replace the battery and alternator with new/re-manufactured battery and alternator? The alternator needs to put out at least 13.6 volts to charge your 12 volt battery or the battery will not maintain a charge. However the alternator runs the vehicle once it is started. The battery is used only to start the car and then the alternator runs it. So if your vehicle starts and runs and then dies you may have a bad alternator. Check your connections first and then test the alternator with a multi meter. Anything less than 13.6 volt will not suffice. 14+ volts would be the hopeful output of a good alternator.
regards, Tony

Try replacing your Belt tensioner and the Serpetine belt. When your A/C clutch cycles the tension changes and your belt is slipping on the Alternator pulley. The A/C compressor will turn off on heavy acceleration to boost speed.

This could explain the light coming on at certain speeds. The modern Alternators contain Voltage Regulators. The Regulator would be the only other part that could cause your problem. Since you replaced the Alternator, it would contain another Regulator.

Make sure the Battery cables are clean and tight. Put both the Tensioner and Belt on as a pair this time. This will insure the tightest fit possible.

As long as you put in a 12 Volt battery connected to the correct terminals, there is little you could do wrong with the battery.

I hope you are happy with my reply and Thank You for using Fixya!

this may be an alternator that can be used for a 6 or 12 volt vehicle I'm not sure but you need to charge 14 .5 volts on a 12 volt system.....hope this helps.....cheers

Purchase a one wire (12 volt) alternator,and install it,and it uses one wire only,the out put wire to the battery from the back of the alternator.Then replace all lamps,and bulbs with 12 volt replacements.Disconnect the voltage regulator completely.The radio,if original,will need a voltage reducer,purchase a coil resister to put in line on the positive input to the radio.This coil resister will reduce the voltage to 7 volts,witch will be fine.The starter will work fine,leave it alone.All dash lights will have to be changed also,to 12 volt bulbs.You can find these replacement parts at any N A P A auto parts store.The resister is a part number irc 13,and the alternator will end in a sw,this means single wire.

get one from a 60 or 70 series land cruiser

Hi

If you have a volt meter, set it to volts and hold the negative probe to the alternator body and the positive to the battery positive. If you don't get battery voltage then the alternator isn't grounded and the probable cause is the main engine ground cable either breaking or coming loose.

Very best regards

Geordie