Hi, I have been having some voltage light woes, and after 2 new batteries and 2 alternators, we(me, mechanic, and autozone), have determined that my voltage regulator is bad, thus causing my battery to go bad, and making a false reading that the alternator is bad. Sooo, I was told by my mechanic that I can go to a salvage yard and get one from a 1999 chrysler LHS with the same engine for about $40. If I go to the dealer I will pay atleast $200, and probably another $180 in labor.

I was just wondering where exactly the PCM is located, I am thinking of looking it up in a hines shop manual, also I have been reading about modules for this car, and is it absolutely necessary to have the dealer replace the PCM? does it even need to be flashed to match the other modules in my car.

Also I only assume I need to have the PCM replaced because autozone says the Electronic Voltage Regulator is located inside the PCM. I also read that it MAY be possible for the dealer to re-flash my current PCM to make it work correctly? Here is a link to where I am getting this information.

http://www.autozone.com/autozone/rep...96b43f802d6596

 

lets see here was it your famous mechanic that said u need the alternator replaced ?? Has he bothers to even test the input and output to the alt or is this a guess job again?

Second do U have a gray key because if U do U only have one choice in the matter and that would be to replace the pcm with a brand new one that is A already programed to your car only or get one from the dealer and have them install and program it.

3rd what ever dumb *** told U that flashing the pcm would solve a hard ware issue inside the pcm should not be on your Christmas card list any more.
Have u ever had Microsoft come out with a software patch that corrects a burnnt chip in you computer at home? humm no.

 

Thanks for your reply. Well no, it wasn't my mechanic that said to replace the alternator to begin with, it was the previous owner, the one who sold me the car, said "the voltage light was on because of a bad alternator". I test drove the car to my mechanic before buying it, and he tested the input/output of the alt, he agreed it was bad, by saying "its not charging like it should be, or it could be the cars computer", he said those 2 things right off the bat before I bought it, he told me "it could be as easy as a new alternator like the guy who is selling it to you says or if its the computer, thats gonna cost you more, but we will work on it, its a good deal", so I bought the car.

Yes I have a set of 2 grey keys, which i think have the chip inside of them. I went to the dealer today, they say its $545 for a new PCM, and $220 for labor to put it in. I checked on Ebay and I can get a PCM programmed with my cars VIN and Mileage for about $200, my mechanic told me though like I said, that if I go to a salvage yard, I can get a PCM off the same year, make, and engine as my car for about $40 and it will work, but I think he may be wrong on that, unless the PCM doesnt need to match up the VIN....oh and the "re-flashing the PCM might make the voltage regulator work again", I read that on some other forum while looking for answers, its unbelievably hard to find forums or posts with answers about 1999 chrysler lhs electrical issues.

 

get the already programed one your mechanic has no clue about Chrysler cars then.

 

yeah, I think that is what I am going to do. I have had the car for 2 weeks in the driveway now, its a sweet ride, but it only lasts maybe 30 minutes before the lights dim and then the abs and trac light come on, and that damned voltage light comes on after about just 5 minutes of driving.

I called an old buddy of mine who owns a shop in California. He told me "he has never seen a PCM go bad on a 99 lhs, he said I bet you its the plugs on the back of the alternator, its not getting enough power", he suggested I take it to an auto electric shop and have them do a starting system check for about $40, he told me to write down what the volts/amperage was with the key in and key out, on all the wires coming from the back of the alternator. Ive looked and all I see is a green and a red wire going into the alternator, aside from the main output of the alternator. Thank you for your replies/suggestions.

 

a true shop or tech with a good scanner can turn on and off the PCMs ground and power supply and test at the connector if its has all it needs.

 

What is this area? it says "Cavity 6 15 amp Lt Bl power outlet", in the owners manual, and inside the fuse box panel to the left of the steering wheel it says "6a IGN 6b BAT "6 15a Lighter Ign/batt" I wonder what the abbreviation Lt Bl means, its the only such abbreviation given after the cavity slot and amp rating of a any of the fuses in my manual.



Uploaded with ImageShack.us

 

Alright, well I took the advice of a good friend of mine who owns a couple shops in CA and has been a professional mechanic for about 28 years. He told me to go to an auto electric shop and pay to have a full charging system check done, because I was about to buy a new PCM which would have cost me about $200 from ebay, and maybe another $50 in labor to have it put in.

He told me look, it might cost anywhere from $40-$100 for the full charging system/electrical system check, but IT WILL BE WORTH IT, if you take it to a place that specializes in car electronic systems, they will be able to tell you for sure what your problem is, at least then you will know whither or not you need to buy a new PCM, but I will tell you in 28 years, I have never seen this type of car have a bad PCM needing to be replaced or cause the problems you are telling me.

So I took it to the most highly recommended auto electric shop in my area, and they were very nice, told me "if there is a problem with your charging system we will find it" so that kind of assured me.

Turns out the problem with my whole voltage light situation, was that on the positive battery cable someone had put a 40 amp fuse in-line with the cable, dont ask me why it was there, the guys at the auto shop said maybe someone put it there because they were trying to setup an after market cd player or something, but anyways, my alternator is supposed to pump out up to 120 amps of current to the battery, well that 40 amp fuse was in the way, bottle knecking the charging system, so it was making the alternator work extra hard because the computer was telling the alternator the battery is not being charged so work harder, and it was, but because that stupid 40 amp fuse was in the cable line, the battery could get no more then 40 amps of current, and if the car demanded more current, it would just blow the fuse, and the battery would drain pretty quick while the car ran. So yeah, in the end, had I given my good friend in California a call from the start, or maybe been given advice to go to a auto electric shop, chances are I wouldnt have needed a new alternator, or a new battery, so I ended up putting out $250 for new alternator/labor, and about $90 for a new battery, and about $60 in gasoline going back and forth between my mechanics home and my house and getting rides back and forth for 2 weeks so the car could be dropped off and worked on. In the end a good auto electric shop is all it took to fix my particular problem and it cost me a grand total of $218 including labor and a new wiring system to and from the battery/alternator. Now I can drive me sweet new ride. FINALLY WOOO, its nice to drive for more then 10 miles without that damned voltage light coming on and my power going out.

 

My battery keeps going dead. NTB has now replaced all the belts, put in three new batteries, and now three new alternators. They showed me a chart reported to be the voltage and it looks like an earthquake in progress. They suggested I go to an electrical specialist to see if something is drawing down the battery when the car is turned off, or to the dealer for a new regulator, or computer. Is the "computer" the "PCM"?

 

if there is something turned on it will kill the battery a good electrical guy can find it Doubt full a pcm is bad. and alternator for sure wont kill the battery when not running