ok, so i misplaced my build sheet, but have a few questions. my stock alt is a 117a alt. however the alt fuse is a 140a fuse. however from what ive heard/read.... arent the fuses supposed to go in accordance to the alt size? 136a alt 140a fuse? so why does my truck have a 140a fuse when i only have a "tiny" alt?

i think im going to buy a 136a alt when i buy my new batteries come tax time to "help" my dual batt. setup.

if someone could clear this up for me it would be greatly appreciated.

 

Not sure on your question, but if you want more charging: http://cgi.ebay.com/ws/eBayISAPI.dll...p2045653.m1253

I'd be afriad of frying something though. I thought about getting one for about 1 second flat, then decided not to burn down my truck.

 

I am running a 250 a alternator on my Yota and my RV. No problems after years. The fuse will go before anything fries - if everything is wired and fused properly.

 

it sounded better in my head apparently..... wanting to know why i have a 140a fuse with a 117a alt. i thought that the higher fuse was for a larger alt.... wanted to get some info on the subject. google wasnt too helpful this time.

 

The alternator is rated for 117 amps (don't know duty cycle) but if current exceeds alternator for a short period, the battery reserve should carry load. The fuse should go before alt is compromised. Fuses work off current (amps) and time. I do not know what the time/current characteristics are on automotive fuses, but data should be there somewhere, probably manufacturers website.

I plan to put a 250 amp in my Ram if/when I have to change it.

 

i would guess there is a 140 amp fuse just in case there is too much draw put on it. it is kind of the same as running a 40 amp fuse on a 20 amp fans. if you had a lower amp fuse it would constantly being blown.

 

I am assuming that you bought your truck used. Givin that, I bet it is likely that the alt. was replaced by the previous owner at some point. Also willing to bet that the part store possibly didn't have a 136 in stock so the 117 was put in. Or, the mechanic shop just threw one in and didn't pay attention to the amps.

Either way, it's a possibility.

 

too good to be true?

 

i did indeed buy the truck used. although it has a stock oe denso alt in it. im almost positive my build sheet said it came with a 117a alt. im just wondering if the wrong fuse was put in, or like crazy said it was put like that from the factory for obvious reasons.

 

Good possibility. And that's cheap for the alt you found!