howdy jeepers! name's remy & i loooove my seXJ

to start things off for myself, big thanks to the admins & all members for providing this world to explore/learn/share....excited to be a part of it

sadly, my 98 4.0 xj has been parked for the past 4 years....good news is, finances are back up, & its being restored for daily use & for what jeeps were made for, 4WHEELIN!!

current project is new red top optima, upgrading the stock 90 A alt w/JY "136" A alt out of a 98 zj, & complete new cables....as with all endeavors, couple questions have come up


1} i had the 136 A alt tested at autozone & advanced....one said the alt was bad, the other said it was fine....my question came up with all this....i felt that the operator, where it was said to be bad, didnt kno what he was doin, so i went to the other tellin them i wasnt sure if it was out of a V8 or V6, so they tested it, said it was good & a 136 A....can/should i trust this?? they brought out a new alt (i think it was a a/c delco) & it looked considerably chunkier than what i brought.

2} should i refurbish this JY "136" A to ensure proper output, or while im at it, completely rebuild to acheive more amperage in a small package??


i kno some of this is based on what the draw is on the charging system....well, this all came to be becuz of a siezed stock alt.....from there i decided to upgrade (being an electrician, i understand voltage, amperage, current, resistance, etc.)....only draw right now is a 500W single amp powering 2x12's (600W i believe) & a couple fog lights off a stock yj @ a JY.....i will be putting in more lights, air compressor, & electric fans in the near future....in the distant future will be winch, audio amps, & prolly more i havent thought of right now......i do realize there is a limit before needing a bigger alt/2nd battery

any feedback is appreciated....thanks in advance

 

Since you're an electrician, you'll understand what I'm about to tell you:

The benches at AZ, AA, et al do not check current output. Therefore, you can have a unit "Pass" on their bench but be a "Fail" when installed. Take it to a local shop that specialises in alternators and starters, they'll have a proper load bench. The "chain store" benches usually draw about enough current to drive my Mag-Light, but not my SureFire.

I used to run one of those benches, and I didn't trust them then. You could tell the stores where I'd worked because I'd added a 200A ammeter and rheostat to the bench within the first week, and showed everyone how to use it. (This may have been 15 years ago, but I still had to test Leece-Neville units, and that meant that a 100A ammeter would be useless.)

You'll have a difficult time "up-Amping" the ND136A without some fairly custom parts, so I see a couple of options for you:

1) Overhaul to spec, and gain the 40A or so (I think the 1998 is OEM with a 90A alternator, but I'd have to dig out my catalogue to verify.)
2) Since you have to grind the mounting anyhow, you can get away with something larger. I've posted lists of potential donors for units 120-160A that should work, but they're UNCONFIRMED. If you try one and get it to work, please let me know so I can change its status. You'll have to find the list, since I don't recall where I put it and I haven't encoded the master into HTML to go on my site yet (it's here, JeepForum, CherokeeTalk, or NAXJA most likely.)

Whichever path you take, don't forget to upgrade your wiring. Information on that can be found by clicking the link in my sig (if you have tooling for large-gage wiring, you can do it yourself from the information given - as an electrician. If you don't, you can order it from me. Either way, it will get you fixed up.) The OEM wiring is rated for OEM output at a relatively low duty cycle - say, 30% at full output. I rate for 100% dc and consider the environment, then throw in a "fudge factor" for safety's sake. You are not going to have an electrical fire because of anything I did!

 

yea so how would you go about building up a 136?

 

hey 5-90, most of the info i've gathered throughout the forums has in some way included you.....my plans actually did include getting in contact w/you for a full retrofit kit

ok, so thanks for reassuring me that AA & AZ are not able to tell how much current is produced (believed this was the case)...& that the alt i have is not what i wanted

this alt supposedly was taken out of a 98 V8 zj....ive seen talk of having to grind the mount for fittment, though what i have bolts directly into my xj, with no grinding or mount modification whatsoever (i now believe its out of a V6)......the plan was to go with a higher output alt that just bolted on & upgrade the wiring accordingly....i kno mean green & power master make upgraded bolt on alts, but i cannot spend that at this point

regarding your "first option" suggestion, 1998 4.0 Cherokee Sport OEM is 90 A (i think 99+ did 117 A alts on xj & yj)....are you saying i should get the 90 A casing rewound & new internal components to gain 40 A? which is not an option, as i left it at the JY as core.....if so, why would this be an easier option than "up-amping" a 136 A?

i picked a 98 zj to swap from, referenced in one of these lists....i saw durango, dakota, zj, & (i think) ram

regardless, ill be e-mailing you for the KWiP retrofit kit

 

I'm working on a "master donor" list as part of my research for Swappology anyhow, I just haven't gotten it done yet. Once I finish organising things, I need to see about spenidng a couple of after-noons with Rod to take pictures and measurements of everything...

I don't think the 90A casing can be easily rewound to give 136A - armature's too small. That case should fit 117A parts handily (the later 117A alternator is the same size as the earlier 90A,) but the 136A is physically larger - you end up needing to grind away about 1/4" thickness at the mount to make the 136A fit in place of the 90A or 117A. I believe the cases for the 140A and 160A units are similar, although I have yet to confirm this (it's on my list.)

 

so for the 136amp can i safely get away with out rewiring?

 

well, i'll be taking this alt to be properly tested, & then decide whats the next step....i am after higher amperage than stock & wiring that can support....i could settle for a rebuilt/up-amped 90A



not quite understanding.....correct me if im wrong, but from what 5-90 has said, if you're trying to up-amp a 136A alt to achieve more, it is possible as the overall size of the casing & components have the capabilities....where 130+ CANT be (or easily/safely) achieved is with a 90/117A alt

if you're talking about installing a 136A alt without installing larger gauge wiring to it/starter/grounds & bypassing the factory fusible link, it'd be a pointless install......literally, the output current of the 136 (measured in amps) will flow thru the factory mains/secondarys, but not safely & not for long....you're seriously running the risk of the melting the wire's insulation, in turn, short circuiting, in turn electrical fires or frying something in the charging system (alt, battery, starter, etc.)....this is all if the fusible link even survives start up (doubtful), it will be overloaded with the higher amperage of the 136....real basic, think of current (amps) like water in a hose....you wouldnt wanna hook your garden hose to a fire hydrant....you've upgraded your power, but you're putting too much pressure in the hose, which will tear apart the hose from the inside....if the hose even momentarily holds, upon release, it'll destroy your flowers (electrical components)

 

sry for so many questions but what would i also upgrade? cause i got the alternator. i just wanna be safe!

 

If you've upgraded your alternator, you'll want to upgrade all of your mains as well. The OEM mains and protection devices are generally sized for the OEM alternator, specifying a 30-40% duty cycle at full output (fine for the typical driver, but not for us...)

Remy - I like the anlogy. Water flow is usually what I use when I need to explain electricity ("voltage" = "pressure," "current" = "flow rate," "resistance" = "restriction," and expand PRN,) but that also serves neatly for explaining why you need a certain size of "hose" for a certain "flow rate" (voltage is largely a non-factor in conductor sizing - just insulation. The conductor is rated using "ampacity," while the insulation has a "breakdown voltage" rating.)

The headache arises when people think they just need to upgrade the lead coming out of the alternator - not so! The ground return should always be the same size as the power feed or the next size larger (next gage smaller,) or you're still going to have restrictions in the circuit.

Look at it this way - the typical shower has a 1/2" pipe behind the shower head and a 1" drain. If that were reversed, what would happen? All I can say is that you'd better have an extra drain in the floor outside the shower, you're gonna need it!

Since you're upgrading mains, you may as well get them all - you'll want to upsize the lead out of the alternator (and associated fuse,) the lead between the battery and PDC should be upgraded (if the battery is low, alternator output not used to run the vehicle will be run to the battery to recharge it,) and the grounds (all three of them - battery-chassis, battery-engine, engine-chassis) will want upgrading.

The only thing left at that point is the starter motor lead, and reports from the field show that upgrading that lead will reduce cranking time (more current can get to the starter more quickly - you're needing to push some 160-180A into that motor to spin the engine fast enough to start...)