2nd Gen Non-Engine/Transmission Alternator woes

[PSoffe]

Last week I had noticed that the voltmeter took a dive and the chime for the "Check Gauges" went off, drove home, approximately 10 miles shut the truck off and turned the key to on and the gauge is back to reading 12-13V. Started truck just fine gauge plummeted again. No choice drove it the next day, the grid heater cycled as normal initially reading 12-13V headed down the highway, normal 14V. this goes on for a couple of days. Batteries all the while are reading 12. 8 to 13V on the voltmeter.



I read an earlier post concerning this very problem, I installed a new(reman) alternator which lasted all of about 15 miles and did the same thing. Should I be concerned that I may have a potential untraceable short somewhere or would you chalk it up to a poorly built reman alt?



I have a brand new part on the way but am affraid of blowing this up as well.



My real question, is if there are fuse, fuseable links and relays, then how is it possible to bypass the supposed safety nets and loose the alternator?

 

[TDRadmin]

Moved at the request of originator.



Robin

TDR Admin

 

[Nate]

It's very possible the new alternator was junk to start out with. I would try and get a new one and start with that.

 

[MHagen]

I just put a new alternator in mine last week to. 197K isnt so bad. buy a reputable brand. we install Autolight alt at our work and we never have any problems, plus they have a lifetime warrantee.



Mike

 

[LMcCary]

Have the new Alt. tested, to be sure that it is the problem. It could be the PCM or wiring to the Alt. A little tessting will find the problem. Oh and be sure that you test Bat. cables, esp. the neg. cable for good connections. A simple volt drop test will find the condition of these.

LMcCary

 

[BigPapa]

Mine went out a few weeks ago after 273K miles. I took it to a place in Nashville that builds/rebuilds alternators. They took it apart, cleaned it, and put new brushes in it. He said the bearings were OK. Cost me @$35.



Scott

 

[DieselDoghouse]

Having just been there a few weeks ago I would strongly rec getting any new alternator load tested before you leave the store. Some come from the plant junked and before you start tearing down the harnesses or the PCM you can know it was good.

 

[BigPapa]

My alternator tested good at 2 Auto Zones, Advance Auto, and an O'reilly's store, so all "tests" aren't reliable. The fellow that tested it where I had it fixed said "It tests good on the tester but I bet it's no good on the truck under a load. " He was right.



Scott

 

[Coalsmoke]

I learned a while ago that if you pay the extra bucks for Bosch alternators and starters, you will never need to buy another one, and if you do, there is a lifetime warranty on them so bring it in and bring a new one home. I had many problems with cheapy starters and alternators that I think worked fine on a testing machine at the rebuild factory, but they didn't stand up to the actual hard-usage of the Cummins.

 

[PSoffe]

Hey guys,



Thanks for the input. New (no more reman) alternator, two new batteries and a couple of new cables. I don't want to leave anything to chance. I need the truck, were going riding in Pismo in a couple of weeks. Thanks again for the all the help and confirmation. If anything changes I'll let you know.

 

[Hammer]

Have you checked the battery cable that goes down to the starter?



It goes down and attaches to the oil pan and almost always they short out at some point and cause the systems your describing. If you haven't then I would look it over good you may be suprised at what you find.



I just installed a new alternator for my 12v this weekend. Mine had 160,000 miles on it and with the added additions of a FASS and Flex-A-Lite fans and the stereo I just wanted to prevent any problems from arising. I orderd mine from Mean-Green and its a 205amp version... ... . Andy



Mean Green Starters and Altenators - Mean Green is the manufacturer of Gear Reduction Starters, Altenators, Stainless Steel Receiver Hitches and Jeep TJ Dual Battery Trays.

 

[PSoffe]

Well, not the results I was hoping for, nevertheless here's what has happened.



I have changed both batteries, brand new, replaced the alternator, brand new, battery cable (ground on drivers side) had a broken clamp, checked all connections, test fuseable link, O. K. , check for wear possible shorts on all positive cables recheck wiring in FASS fuel pump (installed two weeks ago) oddly enough this is when my problems started but can't understand why this would have any corrilation, but anyway. I have checked all the fuses that would even remotely have anything to do with either the charging or grid heater.



So here goes, I turn the key to on, 12. 5V on dash, truck starts fine no change actually drops slightly unmeasureable but enough to see the needle move slightly to down side.



You see I am accustom to the voltage being low at start up do to the grid heater cycling and then increasing to the normal 13. 8 to 14V so I had pulled the relay thinking that maybe the weren't cycling as they should. No difference. Drive the truck computer obviously reads the less than 10. 8V as I am told and gauge goes to zero.



I plugged in my Actron code scanner hoping to find a code and nothing.



Now what? Any Ideas? Does anyone know a reputable reliable mechanic in the Temecula (southern California) area that I could bring this thing too. I'm not ready nor financially stable enough to take it to the dealer where they can have there way with me, but this may be my only option.



I'm tired and frustrated.

 

[LMcCary]

Is your alternator controlled by the computer? In other words, does your alternator have two small wires conected to the back of it? If so, while the engine is running, carefully check to see how many volts are going the these conntection point. It should be about 9 to 12 volts. If the voltage is not there , then the field cannot be energized, so no charge. These wires are connected to the ECM. Sometimes the wires break close to the connection or along the way to the ECM. Have you or anyone else possibly pinched these control wires while running new fuel lines or any other repair? Do you have a tach? If the crank shaft sensor is not recieving a strong signal, then the ECM will not turn the alternator, so check the sensor and wiring. Sometimes the pins come loose in the ECM. In that case, it is ECM time. Hope this Helps.

LMcCary

 

[PSoffe]

Well we will see what happens tomorrow, she's goin' to the dealer. I can't find anyone local that is familiar enough with these trucks to trust, not that I can trust the dealer but at least they will have what they need at there disposal.

 

[PSoffe]

Unbelievable

So I take the truck to the local Dodge dealer, it's there for 4 hours, they check the entire charging system and what they refered to as a comprehensive check of the PCM.



"Bad alternator". Unbelievable, two alternators, two batteries, two cables. almost sounds like a Master Card commercial the only problem is that it isn't priceless. Dealer nails me for 600 bucks live and learn I guess.



I'll pick it up this evening hopefully it truly is fixed.



I thank you for the assistance.

 

[PSoffe]

The plot thickens

So I get a call from the Dodge dealer today and he informs me that the alternator is now working just fine but now the ECM is failing. I new these guys were gonna take me for a ride.



Now the bill has gone from $600. 00 to $1050. 00... That's what I said!



How can an alternator be bad and the ECM good one day and the exact opposite the next with a new alternator installed?



Man my head is spinning.

 

[Shelby Griggs]

This won't help Pat, BUT you can get brand new Denso alternators from LarryB's for $180.



Alternators



When my OEM goes that is going to be my replacement source, 185K and counting on the original, that is a price I can afford to pay every 200K or so.



I have never ever had good luck with reman starters and alternators, if they work at all, they give them a "Krylon" rebuild and out the door!



SHG