i am currently adding 4 55w off-road lights and a stereo system to my 91 zuki. just wondering if the small alternator will be able to handle the additional electrical load that i will be putting on it if i have these things on as well as the headlights and heater or air conditioner. also if anyone has upgraded their alternator, what kind did you upgrade with as well as any modifications were made to get it to fit......and so on?
watts is equal to volts times amps so it takes 5 amps to run each light total 20 amps another 5 each for head lights total 10 amps fan motor I'm guessing 5 to 10 amps grand total 40 amps almost forgot stereo 2,000 watts 190 amps lots of links out there , it's a popular swap on the 1.0 Suzuki offroaders. http://xfaktor.net:8082/Projects/Suzuki/gmalt/gmalt.html
i've seen the 1.0 motors with 35 & 55 amp alternators. if i had to guess the smaller motor without air conditioner would have a 35 amp one. just to reduce parasitic drag and help with fuel economy. i do know that they look the same on the outside . you could put an amp gauge on it & see if it was keeping up. on the Metros the larger unit had a 4 rib belt & the older style 35 amp had 3 ribs . it would also slip the belt when you first cranked it and tried to turn to much on. i have a few laying around , if they are larger than your's i'd be glad to send you one.
for many years i put 300 amp or larger alternators on 12 hp yanmar diesels. when you are crossing oceans in a sailboat that only holds 40 gallons of fuel, you make sure every drop either pushes you forward or fills your batt bank. The thing about alternator upgrades is this. once you stop limiting your self that it has to be the same size as the one or has to fit the same brackets, the sky becomes the limit. or the size of your engine box does. If you decide that you really do want to be limited by original size, bracket, whatever, then consider taking your alternator to your local Alternator/generator rebuild shop. Then ask what they think they could wind it up to. you might be surprised. the stock delco frame alternator in my jeep that was rated at 63 amps but i only measured at 54, now measures at 143 amps with a pulley 20 percent under size at 2200 rpms.
there are alot of ideas out there on the alternator idea. I have to agree with Cumorglas if you can spare the room adding a slightly larger frame is the ticket. My Suzuki Samurai has a 1.3 liter, and came with, i think, a 45 amp alt. with a slightly different bracket I am now running a GM alt that was tested at 117 amps. plenty of power now...
My Suzuki Carry's alt runs at an even 40A output. Typical for a small kei, with few electrical needs. You can run a one wire type aftermarket alt, the hard part being the mounting hardware.