4bangerjp.com
General Forums => The Mess Hall => Topic started by: chrisfranklin on April 22, 2013, 01:54:31 AM
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Volt gauge was in the red, headlight bulbs blew, tach and speedo gauge needles were bouncing a little bit. Tested the terminals with voltmeter and battery was 13.5v just after shutting off ignition, roughly 16v at idle. So apparently an overcharge situation -- often due bad alternator. Checked all the wiring, connections, grounds also.
If had the time, would have pulled the 1st alternator and had it bench tested, but couldn't do it. So replaced my 220amp alternator with another make, also high amp, 250amp. Put in some replacement bulbs -- same fatboys as before. Also bought a new DieHard Odyssey on the off-chance that the Optima was as fault even though it tested fine.
New alternator, battery, bulbs, things appeared to normalize.
Day later, on highway, night, headlights blow out again. Tach and speedo gauges occasionally bouncing and volt gauge (had my eye on that) was moving around...
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Can pull this second alternator, have a shop test it, but my bet is that it's going to test fine (wouldn't be surprised if first alternator was fine). New battery likely
fine (wouldn't be surprised if first battery, the Optima, was fine)
Assuming new alternator is fine (yes, I know -- don't assume; do it here, for me, please), here's where my deal is at as far as "unturned stones:"
- Voltage regulator in PCM has failed -- replace PCM
- Or bypass PCM and its potentially bad voltage regulator and an install external voltage regulatorhttp://alternatorparts.com/external-voltage-regulator-high-output-alternator-kit.html (http://alternatorparts.com/external-voltage-regulator-high-output-alternator-kit.html)
- Also possibly pull the high amp alternator and install an oem unit or an uprated version.
Read a few anecdotes about high amp alternators frying voltage regulators and '91 and later Jeeps having PCM-housed regulators do just that (news to me).
Questions:
1. Say it's the PCM voltage regulator -- replace the PCM (refurb at $120-200). If my high-amp alternator had something to do with my PCM's voltage regulator the first go around, and assuming my first and second high-amp alternators function/functioned normally, would not my new PCM's voltage regulator fail again (am not entirely familiar with PCM voltage regulator life-spans or their compatibility/incompatibility with high amp alternators)?
2. External voltage regulator -- ok bypass the dead voltage regulator in the PCM using the kit. Will this external regulator cope with a high-amp alternator?
Was looking for posts at jeepforum and other sites and surprised didn't see anything that fairly closely mirrored my electrical problem in this case.
Anyway, thanks for any help. +/- and all that.
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It sounds like it's the PCM voltage regulator. Probably best to just change the PCM.
Had not heard about the high amp alternators causing problems but for what it's worth my 75 amp and now 90 amp alternators have always handled charging just fine with occasional winch pulls. Keeping in mind that my YJ has no extra lights, not even a radio, just the ARB compressor being turned on once in a while.
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Thanks Neale.
Beginning to wonder whether I opened a can of worms ever doing the 210-250 high amp alts (error earlier -- said first alt was 220amp). Idea was to buy a little amp "overhead" to cover an electric fan install (Mark VIII fan I bought has been in a box at my place for about 6 months now...) and maybe an audio amplifier and better speaker setup. Didn't see anything online or specifically w/ jeep accessories retailers about people with Wranglers having any problem with high amp alternators, so decided to do it.
Last few weeks jp electrical situation has been kicking my a55, though.
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bump
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something you should look into: what is the field current draw on your 250Amp alternator and what is the PCM max supported current output on the field control wire
reason i mention this is if you replace your PCM (which is the problem by the looks of it at this point) it might not last if the control field current is over the limit, so in the end an external regulator could be the way to go - just something to consider.
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something you should look into: what is the field current draw on your 250Amp alternator and what is the PCM max supported current output on the field control wire
reason i mention this is if you replace your PCM (which is the problem by the looks of it at this point) it might not last if the control field current is over the limit, so in the end an external regulator could be the way to go - just something to consider.
Was thinking the same thing. So right now on fence, but would tend to give the external voltage regulator kit a go.
Saturday, when my second set of bulbs blew and same electrical problems emerged again, I was blacked out. No high beams/no low beams and about 14 miles as the crow flies from my place.
So, I kicked it for 6 hours until the sun rose, expecting to drive it back. 6AM -- Wouldn't turn over. I'm wtf?
Battery is fine. I walk away because I'm pissed thinking about the tow I'm going to have to hire. I get a donut and some coffee, come back in an hour. Try again. It decides to start and I'm giving it gas to get it running. Manage to make it back to my place.
Thing is, got myself into a really first class cluster-4uck in the last 6 months...
Dude in my building, November last year, says: "hey like to use your Jeep in a full-length zombie picture I'm shooting. Pay for the nights using it."
"Ok," I say, thinking it'd be good for some laughs.
So last November went fine, no problems. Dude said he'd start shooting the other scenes in February, this year. Well, this April, dude finally starts wanting to shoot the other scenes.
I say, "Vince (substitute name), Jeep is having electrical problems, lights blew, you can use it for day shots, but nights it's no good until I can figure out the problem...and that could be awhile. He's like: "well I got to have it fixed, I'll pay it." I said, "ok."
Shop says bad alternator, says install new alternator. I want par with what I had before, not shop's oem quote. So I buy a 250 high amp replacement and some bulbs, shop installs them.
"Vince" gets another night shooting last Friday. Then bulbs blow again -- electrical problem still there. Tell him this a couple of days ago. He's like: "oh need it by May 9 working again, will pay for it."
Yeah great -- thing is "Vince" doesn't know what he's getting into. And, yeah, there's some "commerce" here with his production's use of my Jeep, but we're not talking a financed feature here. "Vince" ain't rich - he 4ucking lives where I live...
Have my head on too many things, distracted. Need to go to the drugstore this morning, am not feeling well. Hop in Jeep, get what I need. Come back out to the lot, Jeep won't crank. I'm like -- "jh wtf am I thinking even attempting to drive this thing."
So, stuck in a private drugstore lot -- 30 minute we-tow joint. I sit there for about 90 minutes - nothing. Forced to call for a tow, pay for the tow, tow it to the same shop as before, then $80 to leave it there so they can look at it again...
There's no conclusion on this post. Just beside myself right now.
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if it didn't turn over then it wasn't charging and not that it was charging too much, unless the battery went bust due to overcharging it but it wouldn't happen in 1 day driving like that. I don't think a lack of ground can cause the overvoltage but maybe a bad ground could and can also explain why it didn't charge the battery, i'm not sure but might want to double check that as well.
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if it didn't turn over then it wasn't charging and not that it was charging too much, unless the battery went bust due to overcharging it but it wouldn't happen in 1 day driving like that. I don't think a lack of ground can cause the overvoltage but maybe a bad ground could and can also explain why it didn't charge the battery, i'm not sure but might want to double check that as well.
Ground to could explain why it would not start then start later.
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Ground to could explain why it would not start then start later.
agreed, that probably makes more sense since it wouldn't have recharged on its own
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Will look for a bad ground - jp is still sitting in a small repair shop lot, but will see what I can do.
Happened across a series of three posts yesterday that are probably the first I've read describing symptoms of an electrical problem like my jeep's:
http://www.jeepforum.com/forum/f12/over-voltage-343861/ (http://www.jeepforum.com/forum/f12/over-voltage-343861/)
http://www.jeepforum.com/forum/f12/over-voltage-part-2-a-348156/ (http://www.jeepforum.com/forum/f12/over-voltage-part-2-a-348156/)
http://www.jeepforum.com/forum/f12/over-voltage-part-3-final-chapter-353841/ (http://www.jeepforum.com/forum/f12/over-voltage-part-3-final-chapter-353841/)
The guy had listed them under "over-voltage;" I had been searching "overcharge." Ran in to them, I think, searching pcm+voltage +regulator+failure or something like that.
Turning my stomach, but the guys seems like he's saying that some Map sensor wire got exposed/contact, resulting in the problems.
Haven't moved any sensors around, but I can certainly dive in there looking for exposed wires...
Personally I suspect the dealership service department may have sold the kid a "fat" story to bill him $400. If their "line" is for real, wouldn't be surprised if they got the job done with a grand total of 5 minutes search work and some electrical tape.
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If you continue to feel the need for a high amp alternator get one with a built in regulator and one that is self energizing. Nippon Denso makes some pretty darn good alternators like that
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This has some interesting information.
http://bob_skelly.home.comcast.net/~bob_skelly/alternator_conversion/wiring_alternator1.html
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Old post, but the problem was the ground. Thanks for the help on that Sharp, Art, Neale, Grumpygy. :thumb:
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glad to hear you fixed it - which ground was it and how did you find it?
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Good to hear you got it fixed.