I have a '84 ford f-250 6.9L diesel, i believe it has a 60-70amp alt. I am putting a JL 1000/1 with 2 12w6v2 in the extended cab of my truck, what kind of amp draw will I get from that setup and how strong of an alternator should I buy? add any caps, and what brand?
You don't really need a cap. A cap won't help anything... it will actually hurt the electrical system. With the 1000/1, you will be pulling a good 100A from you're alternator. Then you have to factor the amp's you're car needs to run and add that to the 100A you're JL will be pulling. You will need at least a 150A alternator.