mesuring gen output

[1928Pickuppain]

I i need to adjust my third brush recently i rebuilt my headlights and went back to stock set up. Before that i had the sealed beams set up and needed the gen cranked up way high so i could drive at night. I plan on bringing it down so that i stop blowing my tail light bulbs when headlights are of in daytime also so i dont fry my battery. i want to have one amp of charge when headlights are on my problem is i dont trust my cheep repro amp gauge to go by. what do you use to relibly check the ampage output from your generator? I do have a multi meter but it dose not measure amps.