Battery or Alt.

[happy024]

In my 95 2.5 YJ My volts have been steadily sinking the last couple of weeks. When i say that I mean that it tops out at 10 to 11 volts on the guage. I've never replaced the battery since I've owned it. Which is about 4 years.

Now I remember someone saying that there was a dodge Alt. that you can put on a YJ that bolts right up and runs a higher amp. or more power (sorry don't know the right words to use)

And if it not the Alt. What Battery is a good Valued buy. I know the Optima is the best but a little pricy from what I see.

Thanks for the advice

 

[Saurian]

Hmm, you're all over the place with that one, the kind of problems I like to solve...

I'm thinking alternator. Once started and running, you can pull the battery out if you like, it's purpose, in layman's terms, is just to hold power to start the vehicle; when you go out and turn the key and nothing happens, your battery has gone south... Alternator will get weaker and weaker till it finally stops working, by that point, you'll be noticing battery problems because it's not being charged enough to restart the Jeep...

I recall that the alternator that can swap in is from a Dodge Dakota, cannot remember which engine or year... All alternators produce 12 volts, that's standard automotive power... The dakota one kicks out more amperage, which means you can run more crap at the same time without overloading the capacity of the alternator and killing the battery...

 

[Bounty__Hunter]

Sounds like a bad battery.

The 136A alternator that will bolt right in is NipponDenso part number 56027913 found in late '90s Dodge fullsize vans and trucks. Check out www.car-part.com for a lot of them available used. You only need to swap the plastic boot on the back and it'll bolt right in. The pulley has one extra groove, you can use it or swap on your 2.5L pulley.

It's a sweet upgrade, nearly double the 2.5L YJ's 70A output.

 

[happy024]

Thanks for the help guys. I'm going tonight and get a new battery. Becuase now its starting to have problems at start up. Whats the minimum Cold cranking amps I should be looking for. I will be putting a winch on soon.

 

[Bounty__Hunter]

If a winch is in your future, go with a deep cycle Optima, either the yellowtop or the bluetop. I went with the bluetop Optima and am very pleased.

 

[Craig]

Your best bet would be to take it into a shop and have them test both your battery and your alternator. A lot of places will test them for free if you buy either the battery or alternator from them.

 

[Craig]

Sounds like a bad battery.

The 136A alternator that will bolt right in is NipponDenso part number 56027913 found in late '90s Dodge fullsize vans and trucks. Check out www.car-part.com for a lot of them available used. You only need to swap the plastic boot on the back and it'll bolt right in. The pulley has one extra groove, you can use it or swap on your 2.5L pulley.

It's a sweet upgrade, nearly double the 2.5L YJ's 70A output.

Never looked into the altenator on my 4.0L. Do they have the same one and if so will this swap work on a 4.0L?

 

[Bounty__Hunter]

Never looked into the altenator on my 4.0L. Do they have the same one and if so will this swap work on a 4.0L?

Yes, as long as you have the NipponDenso type alternator, which I think most or all '91+ 4.0L jeeps do. The common 4.0L alt. is like 90A, so the gain is smaller compared to the 2.5L upgrade from a 70A alternator. Still an upgrade nonetheless.

 

[88Wrangles]

I'm thinking alternator. Once started and running, you can pull the battery out if you like, it's purpose, in layman's terms, is just to hold power to start the vehicle

Not quite. Anything that needs electricity will not work on your vehicle without a battery. And it being '95 I'm guessing it is fuel injected and is at least partially computer controlled.

 

[Saurian]

Hmm, I thought the alt made enough power without the battery having to be there as a storage unit, could be wrong though, my primary learning was on considerably older vehicles...

 

[jaymz77]

Hmm, I thought the alt made enough power without the battery having to be there as a storage unit, could be wrong though, my primary learning was on considerably older vehicles...

Your alt is an elctromagnet powered by the battery if you diconnect the battery the alt wont have power to run the electromagnetic field. If your are only producing 10-11v you probably have an open in the windings of your alt. A good alt will produce 13-14v with the engine running.

p.s. I'm studying for my aviation A&P liscense and just took a class on all this crap.
p.s.s. I failed miserably.

 

[Bounty__Hunter]

Hmm, I thought the alt made enough power without the battery having to be there as a storage unit, could be wrong though, my primary learning was on considerably older vehicles...

That used to be the case on older vehicles, but not so much anymore. Too much electronics and computers.

 

[Sparky-Watts]

That used to be the case on older vehicles, but not so much anymore. Too much electronics and computers.

Yup. I once drove a 1972 Capri from Kansas City to Wichita with no battery in it. The battery had exploded when I tried to start it to make the return trip. We took the battery out of my mom's LTD to start the Capri, then put it back in the LTD to complete the trip.

 

[Gig]

I had a problem with my alt a couple months ago. It wasn't anything electronic though. Mechanical. The belt was starting to slip, since the pulley was worn out (More square than a V) and was just slipping silently. Usually the volt meter in the jeep should read 14V, but with lights and w/e else you have running can go down to 12V(Normal driving, Night Driving) If you are producing less than 14V with nothing on but the engine, something is amiss. The jeep can run without a battery, including everything else like lights, But it is not recommended to run without. The battery also acts like a safeguard. If the filter on your alt is finished, and you rev up to 3000 RPM, where is the spare power gonna go? Into your wires, and burn your fuses out, fuselinks, or perhaps the alt?

Gig

 

[88Wrangles]

...The jeep can run without a battery, including everything else like lights, But it is not recommended to run without...

I don't see how that's possible...

 

[Gig]

I mean after the fact that it is started. LOL But if that is not what you meant, then think about it. Why do people buy deep cycle batteries? For their heavy use of electricity, causing constant battery drainage (ie: Winch, Flood Lights etc...) Why? the stock alt does not produce enough amperage to keep up. Now, if the battery was the source of the power the whole time, and the alt just recharged it all the time, then your battery would die pretty quick, as in not charge fully any more. Remember, on the side or top of the battery, it says STARTING battery(in most cases) That is all the battery is supposed to do, unless you have an electric malfunction somewhere.

Gig

 

[88Wrangles]

Then why can I walk out to my rig right now, start it, unhook the battery, and it dies imediatly?

And this is with a OBD2 rig.

 

[Sparky-Watts]

Then why can I walk out to my rig right now, start it, unhook the battery, and it dies imediatly?

And this is with a OBD2 rig.

Bad kharma? Proton dependency? Tectonic shift?

I'm thinkin' someone said earlier that you can't do it with a vehicle that has a computer (ECM). Now on the older vehicles without all the electronic crap you could. Kill the power to the ECM from the batterey, and the ECM will kill the motor out of protection for the rest of the system. (Sparky's uneducated guess)

 

[88Wrangles]

Bad kharma? Proton dependency? Tectonic shift?

I'm thinkin' someone said earlier that you can't do it with a vehicle that has a computer (ECM). Now on the older vehicles without all the electronic crap you could. Kill the power to the ECM from the batterey, and the ECM will kill the motor out of protection for the rest of the system. (Sparky's uneducated guess)

Yep. No power from the computer and everything will die. Like I said though, older non-computerized cars are different. They're run all day long without a battery.

 

[cougarlasch]

if one disconnects the battery while the truck is running. on the newwer vehicles you can end up frying your alternator cuz it senses no voltage an the computer kicks it into full field voltage. and it can also damage many solid state components which are very expensive.