alternater test?

[purplebeard66]

hello surfers.is there a way for me to test my alternater is o.k. keeping in mind that i am not a very mechanicly minded guy? i have replaced one of my batteries and dont know if the other one needs replacing. the new battery was fully charged yesterday but only just managed to spin the engine this morning.do both batteries have to be fully charged?my 1st gen surf worked fine on 1 battery.

[johnd]

the truck will run fine on one battery , take out the old battery and see if it starts ok , a duff battery will drag the new one down in short order.
john

[NiftyNev]

Connect a multimeter to battery terminals and check voltage with engine running. Rev to around 2K RPM. Voltage should be around 14.8V.

Nev

[purplebeard66]

cheers bud will do

[ronsarrox]

also, with engine running, turn on all electrics (blowers, stereo, lights, heated rear screen etc etc) and rev the engine, put a multimeter across the batt and it should read somewhere between 12-13.t5.

This checks that the alternator is charging under load.