Does anyone else go through alternators like I do?

I'm on my 3rd replacement, and I just killed it last night driving around in town. It's been raining for the past week here and I guess I must've driven through a puddle that was big enough to splash some water/mud up there.

The crappy part is I can't find my receipt for it so I can get a replacement at the parts store.

Anyone have any pictures of an alternator splash guard they built out of some sheetmetal? (yes I searched) I'm trying to get some inspiration, need to get something up there but I'm not sure where to start with it. I never had the rubber OEM splash guard, and the mopar skid is off because half of the bolts broke off when I took it out to do some suspension work.

Have you been running the same battery through all these alternators? Also, have you gone through most of thee wireing to check for splices/frays?

I just replaced mine 2 weeks ago, and the guy at the parts store told me our altrenators are a crappy design. He said they are too small for the kind of power they put out, and they cook themselves. I have put on 4 of them in the 8-9 years I have had my jeep.

cherokee89 said:

I just replaced mine 2 weeks ago, and the guy at the parts store told me our altrenators are a crappy design. He said they are too small for the kind of power they put out, and they cook themselves. I have put on 4 of them in the 8-9 years I have had my jeep.

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As long as they got that lifetime warranty i say it's cool for what it is. :gee:

Yeah, it only takes about 20-30 minutes to swap out, so it really isn't a big deal. I am not going to lose my reciept, this time!!! :banghead:

imma honky said:

Have you been running the same battery through all these alternators? Also, have you gone through most of thee wireing to check for splices/frays?

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No, I changed batteries when the first one went out, just for good measure, so the battery in there is almost brand new, not even 3 months old. I've tested all the connections and stuff, it's just simply a matter of the alternator being in a stupid spot I guess... the first couple I killed when I was in mud, but this time it was just water or something, they just die when anything splashes on them or gets inside or something...

'96 Classic (closing in on '91 Trooper as love of my life)

NotMatt, what year is your XJ? I know they changed the alternator/battery system in '96 for a heavier-duty one. Does anyone know if they also did anything to protect them from getting wet or do I have to add "avoid puddles" to my watchlist? And how about the underspray car washes we have to do all winter for road salt?

Churchlady said:

'96 Classic (closing in on '91 Trooper as love of my life)

NotMatt, what year is your XJ? I know they changed the alternator/battery system in '96 for a heavier-duty one. Does anyone know if they also did anything to protect them from getting wet or do I have to add "avoid puddles" to my watchlist? And how about the underspray car washes we have to do all winter for road salt?

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Mine's an 87 4.0L, I think you're pretty safe as you probably have either a factory skid plate or a rubber splash guard, I'm just unlucky as I have neither, I guess the alternator is just a fragile unit and it's in a bad place to be unprotected.

I'm still searching for my receipt. I had originally put it in my wallet for safe keeping, but then for some reason I took it out and must've put it somewhere "safe", now I can't remember where that is!

Might behoove those who no longer have the underbody splash guard to put one on there. For those of you who have no clue what I'm talking about the splash guard is a neopherene rubber 'bib' for lack of a better term. It attaches under the radiator and down under the engine. The holes rip out and they generally fall apart from tears. I think they are about $50 or so and I do need one, mine lasted longer than most I think because my front skid kept the front part on so it did not turn into a big underbody air scoop...

cherokee89 said:

I just replaced mine 2 weeks ago, and the guy at the parts store told me our altrenators are a crappy design. He said they are too small for the kind of power they put out, and they cook themselves. I have put on 4 of them in the 8-9 years I have had my jeep.

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That's odd. There's only several million of 'em running around in Generous Motors cars and trucks. (It is a Delco, after all) Methinks the guy at your store was having a bad hair day.

Eagle said:

That's odd. There's only several million of 'em running around in Generous Motors cars and trucks. (It is a Delco, after all) Methinks the guy at your store was having a bad hair day.

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I'm guessing he sees a lot of cherokee alternators go through there seeing as how the jeep engineers put it in the worst possible location, and just made a conclusion.

BTW, for those of you with OEM skid plates ... it helps, but the full splash guard is probably better. The first one I killed I still had the mopar skid plate on there, but no splash guard.

IMHO you guys who are burning up alternators ought to be looking for an electrical problem elsewhere. You likely have a bad connection somewhere, or a broken wire, or some odd thing like that that under certain circumstances sends a power spike through your alternator.

My "splash guard" only lasted about three years before I tore away what little was left of it. I'm now 11 years and 236,000 miles of HARD use into my XJ (I bought it new in 93) and have yet to replace the alternator. By hard use, I mean every imaginable horror from sustained high speed runs to slogging through mud and snow and dunking it in more streams and rivers than I could possibly hope to remember (the kind where you have water running past the door seals). I've also known XJ alternators to survive being so filled with mud that they had to have it knocked loose with a hammer and washed out - all to show no ill effects.

I have a hard time believing that a puddle could do anything to a properly functioning alternator tied into a properly functioning electrical system.

Now this is only a theory and its just thru observation but a couple of mechanics I know have mentioned that they get alot of alternators dead over the last 4 years since the state of Pa started using that new blue stuff they put on roads in the winter before a snow or ice storm. Now I know that stuff does a number on frames and bodywork so I have to wonder what it does to exposed components down low like alterntators and air pumps like were on older CJ's and YJ's, as I remember those too were down low and the alt was up high.
I am on my original alt with almost 200,000mi on it. I replaced the battery a few months ago with red top figuring the original battery was getting too up in years to depend on. I also notice that since my sheild is pretty much toast that I get alot more crap up in the compartment that I did not used to get. In my case I am going to replace it.
I don't do alot of deep fording or alot of deep mud, only had water halfway up the doors a couple of times but I do alot of poweline and gas line right of way shortcuts with their hills and muddy stream crossings plus a couple of customers that live pretty far back.
One question that has popped into my mind is that maybe the oem jeep alts could be sealed a different way than a rebuilt or off the shelf new one that is made for many different cars and not jeeps specifically. Maybe DC/Jeeps specs on their alts require an extra coating of whatever that clear stuff is they spray on the windings, only they could answer that question....

The CS 121 74 AMP is standard, the CS 130 105 AMP, bolts right in. If the wiring is marginal, or as mentioned road salt (or coolant), (which are moisture magnets) and moisture are allowing a lot of line leakage, the larger alternator might hold the load a bit better. Price difference isn´t that much.
I´ve taken apart and tested, more than a few CS130 and 121`s (Jeep/pre 90 XJ and Chevy). The most common failure is dirt, mud, coolant or oil under the brushes, not allowing contact on the slip rings, second is a fried diode (usually low charge), then a failed regulator.
I can´t ever remember frying an alternator from submerging it, But have crammed them full of mud on occasion and they refused to work, until the mud was cleaned out.
I´ve noticed over the years, with various Jeeps, they often have a tendancy to overcharge (from FSJ´s, 715´s, YJ´s through the XJ´s up to 91), isn´t good for the batteries and has to be hard on the alternator.
One culpret could be the supplied regulator voltage (I/F yellow wire), the lower the regulator input, the more output. Might be a line loss problem there (corroded/poor connectors, C-100?).
I´m doing some test on the TSU sensor wiring right now, will have a look at the alternator feed while I´m at it and get back to you.

8Mud said:

But have crammed them full of mud on occasion and they refused to work, until the mud was cleaned out.

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Well, since I have no warranty on this alternator since I can't find my receipt, I'm going to go ahead and pull it apart and see if there's anything to be done. Went through some mud a week or so ago, and didn't have any problems with the alt. until last night, but maybe the water sloshed some mud that was in there around and caused it to not work.

Worth a shot I guess, if it can't be fixed it'll just go back to Napa as a core (going to try a different supplier this time instead of Schucks).

Before you take it apart, try spraying really hot water into the back air grate. I´ve used a solvent sprayer (compressed air solvent gun) and almost boiling water. Then blow it out with some air, worth a try. A couple of repeats, as needed. Have also used the sprayer in the shower, when the misses was out.
http://www.alternatorparts.com/cs130_sbpage1.htm , a nice read for alternator repairs.
You can take it apart for a look see, without removing the pulley, leave the windings and the rear parts, in one chunk and pull the front cover, the shaft and the stator out as the other half, be carefull not to loose the bearing spacer (washer) off of the shaft. There are some holes to insert a couple of peices of wire, through the back cover, to hold the brushes out of the way for reassembly.
The case bolts are easy to snap off (oil, a little tap tap tap with a hammer and some feeling will save trouble) and hard to find a socket small enough to clear the case. Mark the case, windings and base, before seperating.

Awesome info man, I will keep everyone updated on my results tomorrow! It will be awesome if I can fix it myself instead of spending 100 bucks on a new one, seeing as how I'm out of a job right now.

Wow, I've got a 16 year old alternator in my XJ and it used to go "swimming" every time I got home from a trip. There was a really neat 12-15 foot hole filed with mud and water that I used to enjoy blasting through. I'm sure the Jackonville Airport Authority wondered who was leaving tire tracks throught their landscaping but I couldn't resist. :firedevil I only quit because my turnsignal socket, headlight wiring, ect was getting corroded so bad from all that water. Alternator didn't care less. My only gripe with my alternator is that it's so weak. Just not enought output to run any extra goodies. If mine can tolerate being soaked and sprayed at its age then there's got to be somthing wrong besides the alternator design...

You don't always need your receipt. Autozone for example has all my stuff on their computer under my home telephone number. They pull up the warranty etc from that number so I don't need the receipt but I keep them anyway since sometimes they forget to list the purchase under my tel number. Call the Shucks you bought it from and ask them if they have it in their computer under your tel. no. Greg

NotMatt said:

Well, since I have no warranty on this alternator since I can't find my receipt, I'm going to go ahead and pull it apart and see if there's anything to be done. Went through some mud a week or so ago, and didn't have any problems with the alt. until last night, but maybe the water sloshed some mud that was in there around and caused it to not work.

Worth a shot I guess, if it can't be fixed it'll just go back to Napa as a core (going to try a different supplier this time instead of Schucks).

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thats why they call it shucks. ( shucks the guy in mexico needs to learn how to rebuild these things. ) :tear: