being as i want to run air compressers and off road lights and the sound system im thinkin im guna need to upgrade my alt. the one i have now only puts out 14.?? volts with all head lights off. i know i have to up grade cuz i have a pretty powerfull sub system and wen its on the alts puttin out 12 sumthin volts. wanted to know if i can get a more powerfull alt that bolts into stock mounts. and if i run a more volts will i need to change anything?

 

Ok, first off, punctuation and correct spelling goes a long ways. Second, what all fo you plan on running? I have 2 12s, 6 big lights, and have run a lot of power off my stock electrical system.
The stock alternator is fine until you are sitting in the campsite running your subs full blast, all 15 lights on and brewing coffee in the coffee maker and filling a monster truck tire up.

 

im runnin 2 type r's and a 1600 watt amp. and i want to get 12 volt air compressers. heat is another bug power suc lol. your sure the stock alt can hold the lights and the sub? do u know how much volts your alt puts out? ive also had problems wid alts blew through a couple in the last few months but im pre sure they were just crappy alts one was rebuilt and one was a junk yard pick. i got jeep to put a new one in after i blew through the second and i havent had problems since and if this one goes im guna get it checked out.

 

I would put a capacitor on the amp to save strain on the battery/alternator.. Also ebay has some high output alternators that bolt right in. I don't know how reliable the brands are though.

 

Everyones alternator puts out 14 volts, give or take. Its amperage your looking for. Stock cherokee alternator is 90amp peak, which is relatively low. And you said 2 Type R's, with a 1600 watt amp. Its safe to say you are not drawing 1600watts from the charging system, being Type R's are rated at 500wRMS. Your problem sounds like weak connections/continuity. I would look into doing the Big 3 Upgrade, change battery-chassis, alt-block, and block-frame, along with the positive wires to a larger gauge, such as 4 gauge. 4 gauge wire will be the largest you will need. Think of it like this, smaller hose, less water, larger hose, more water. Same with wire, if you put in a larger gauge it will allow more current through with minor loss. But like I said, 4 gauge is large enough. Your not going to hook up a fire hose to your house bib and expect it to have any gains over a walmart hose.

No. Capacitors are only to be used in sufficent power applications. They do not help straining electrical systems. Link in my sig explains it.

 

i bought a 136 amp ZJ grand cherokee alternator and put in my 97 xj. i've got 12's and lights and the factory alternator wasn't doing it for me, especially at night and i do have a capacitor for my amps, the lights would dim so much it was crazy, i love the new alternator though. i went to oreilly and asked for a 98 grand cherokee v8 5.2 litre 136 amp alternator and gave them my core. all you have to do is take the mount off of your jeep and put it up to the new alternator and see where you need to grind to make it fit, mine was off by about an inch in 2 places and i spent 30 minutes and i had it back on the jeep and running. it was soooo easy. it cost me i think 152 bucks. alot cheaper than the mean green alternator and better In my opinion, lifetime warranty too

 

Before anyone else says anything about capacitors, please read this and educate yourselves.

http://www.caraudioforum.com/showthread.php?t=319539

 

lol rude much? i know what a capacitor does, i know it doesn't help charge the batter. It sends power when the heavy bass notes hit to compensate the charging system from going so low to dim lights etc...

 

I've been workin in the car audio industry for 3 years as a professional. I think that caps r a waste of money. If u want true power upgrade the alternator, put in a 2nd battery with an isolator so both get an equal charge. U will have plenty of power and some head room for what u want to do

 

But seriously, if you are running all that at the sametime you are wack. When you are using your air compressor turn off your radio, when its a little warm roll the windows instead of the ac. I guess what im trying to say is, after you buy it and put in the new one, it may not be worth it

 

Wasnt really directed towards you, but its a good read lol

 

I just put in a 136 amp re-manufacturered from O'reilly and had to grind a hell of a lot more than I thought I would. I even had to grind the timing cover on the engine. I have a 1999 with 4.0L I think there is a Bosch and a Denso and I think the Denso is a bit smaller, They gave me the Bosch.

Remember you need to change out your Alternator lead, that thing is the fuse for your alternator, so if you are using the OEM it will blow at 90 or 110. (and if anyone can find a 136 amp AMG fuse I would like to know about it)

Of course I have a pair of red tops too...


Nathan
- 99 4 door xj getting there...

 

Hope you realize that grinding the hell out of the alternator like that voids the warranty.

My 2000 XJ came from the factory with a 124 amp alternator, according to the build sheet.

 

Just installed a 170 amp alternator and 2 yellow top optima batteries with an isolator to run all my lights, winch, stereo and 3 electric fans for cooling and haven't ran out of power yet and if i do i'm parking it and sticking to my RZR 900 small winch small lights and no radio