[willie101474]

Hi all. So my son started driving the old voyager. His buddy put some type of extra colored lights in the interior and then it started having problems draining the battery. I checked the battery and my tester said battery life 14%. "Replace battery". With a jump start I headed to the AAA shop to get my free battery replacement. They came back and said my alternator was bad and that needed replaced first. Their test showed 13.21 V unloaded and 13.02 V loaded. The battery voltage was 7.79V. Is this alternator voltage too low or are they trying to pull a fast one? I said something to the mechanic that pulled the car around and he said it should be at least 14V.

 

[BoiseVger]

Sorry if I created false hope by putting this in but I'm having a similar problem with my '98 3.0 alternator: voltage was reading 12.9 volts (read at battery with voltmeter, engine running), battery keeps discharging over 2 or 3 days. This started being a noticeable problem 8 months ago before I moved from Boise to Kentucky, now it's gotten worse. Every time I jump-start the vehicle, the climate-control buttons blink for several minutes and then stop...this comes even after I replaced the brushes in the alternator because the old ones were worn (I even polished the commutator!). Perhaps I should've checked the stator & rotor windings for breaks or leaks to ground...I didn't. And I know the voltage regulator's in the Body Control Module (which makes no sense). Has anyone else had my issue? Sorry to half-hijack the thread, willie's issue sounded remarkably close to mine. Sorry if I stepped on your toes, willie...I'm observing your outcome and others' suggestions. I hope we both get answers soon!

 

[willie101474]

Sorry if I created false hope by putting this in but I'm having a similar problem with my '98 3.0 alternator: voltage was reading 12.9 volts (read at battery with voltmeter, engine running), battery keeps discharging over 2 or 3 days. This started being a noticeable problem 8 months ago before I moved from Boise to Kentucky, now it's gotten worse. Every time I jump-start the vehicle, the climate-control buttons blink for several minutes and then stop...this comes even after I replaced the brushes in the alternator because the old ones were worn (I even polished the commutator!). Perhaps I should've checked the stator & rotor windings for breaks or leaks to ground...I didn't. And I know the voltage regulator's in the Body Control Module (which makes no sense). Has anyone else had my issue? Sorry to half-hijack the thread, willie's issue sounded remarkably close to mine. Sorry if I stepped on your toes, willie...I'm observing your outcome and others' suggestions. I hope we both get answers soon!

The more the merrier. Well not really good if people are having issues. It is possible to install an old school external voltage regulator and bypass the ecm. There are a bunch of videos on this. Here is some good testing info. Not sure if I am allowed to post a link but there is good testing info. My though is to try this test and if that checks out maybe I will go with the external regulator. https://autoprollc.com/wp-content/uploads/2016/12/5-RemyTechnicalBulletin_July_web.pdf

 

[ggoose]

Before blaming the voltage regulator in the pcm it is necessary to diagnose the issue more thoroughly. The test described will diagnose the alternator but nothing else.

Ground wires need to be inspected to be certain they are in place and free of corrosion. A missing or poor ground will limit the voltage needed to properly regulate the voltage output. The power feed to the alternator needs to be checked to be certain all connections are clean and solid.

My opinion, I would replace the alternator. The mechanic was correct in noting the charging voltage should be at least 14 volts. I would also plan on replacing the battery if it is more than 3 years old. A resting battery voltage under 12 volts indicates a weak/failing battery. That the voltage is under 8 volts indicates possible failing cells.

I would also suggest a check of the wiring of the added interior lights. Since the issue appears to have started after the lights were added warrants additional scrutiny.

 

[BoiseVger]

All my electrical is clean, as far as wiring goes: no corrosion, no cuts/splices/elec tape. I've never seen a ground strap near my alternator before. My Vger's bone-stock and nothing is left plugged into my power ports. My battery is almost 2 years old.

So, I guess my next move is to yank the alternator and do two things: (1) do an ohmmeter ground-check to assure the stator & rotor windings aren't broken/shorting to ground, and (2) get it spin-tested. I can get other parts for inside the alternator. Guess that's my next move. At least it's another plan...for now. $175 for a new mill is a lot when one's on fixed income. Do my best, Flex-Seal the rest. thank ye, kind members!

 

[kc27]

Your community may have an automobile electric shop that repairs alternators. I was looking at a similar cost for an alternator on one of my vehicles. The electric shop repaired it for $65. From what you wrote it sounds like you are capable of making the repair yourself. But if crunched for time, an electric shop can be a cost effective solution.

 

[ggoose]

Check out prices on rockauto.com and note there is a 5% discount code over on the vendor tab. If a core return is needed, the prepaid return shipping label is included in the price. I get most of my orders in 2-3 days at the lowest shipping cost.

 

[BoiseVger]

Hokay, I'm back. Took the alternator in to Lance at Advanced (Otto at AutoZone said their machine was broken and Radar at O'Reilly was a bit too far off), he plopped it on, plugged it in, spun it. Verdict...

15.2 volts. She good.

So, this presents the possibility that the PCM's regulator is dying. I hate Chrysler for putting the voltage regulators in PCMs: I had a '90 Dodge 15-pax van that had that and it, too, went out despite a good alternator. After learning the price of a new PCM , I went to a store, got a separate Chrysler voltage regulator, swiped a pigtail off a wrecked van and wired 'er all up a'la my '85 Dodge conversion van. Pieceocake. Zero probs after that. 🥳

So, Willie: I'm not sure what engine ya got, mine's a 3.0 and it's a slight fustercluck to yank, but I'd seriously recommend you pull your alternator and take 'er in to a store for off-rig testing. Tell us what ya got.

By the by, eBay has HD VRs with pigtails for around $21, free 4-day shipping. I'm gonna run that. I took pride in keeping Gretchen bone-stock...but considering she's 24 years old, it's probly best to swallow my pride and convert it all. Ho, well...

I would also suggest a check of the wiring of the added interior lights. Since the issue appears to have started after the lights were added warrants additional scrutiny.

Agreed. I wonder if the addition of lighting and/or an accidental shorting during installation could've kayoed the voltage regulator in the PCM. After all, our vans aren't spring chickens anymore.

 

[BoiseVger]

Back...so I got the best info I could and made up a wiring diagram for the external regulator conversion...

This is how I converted my '90 Dodge van to an external regulator. The regulator I ordered comes with a new regulator pigtail but no retainer clip; I have to go to the wrecking yard and clip a donor alternator pigtail to complete my setup...and, hopefully, find a clip wire to retain the regulator pigtail to the regulator. The dark-green/orange wire on the body harness supplies the keyed 12-volt power to the alternator field and regulator...just make sure the new external regulator is well-grounded via toothed washers. Good luck!

 

[willie101474]

Hokay, I'm back. Took the alternator in to Lance at Advanced (Otto at AutoZone said their machine was broken and Radar at O'Reilly was a bit too far off), he plopped it on, plugged it in, spun it. Verdict...

15.2 volts. She good.

So, this presents the possibility that the PCM's regulator is dying. I hate Chrysler for putting the voltage regulators in PCMs: I had a '90 Dodge 15-pax van that had that and it, too, went out despite a good alternator. After learning the price of a new PCM , I went to a store, got a separate Chrysler voltage regulator, swiped a pigtail off a wrecked van and wired 'er all up a'la my '85 Dodge conversion van. Pieceocake. Zero probs after that. 🥳

So, Willie: I'm not sure what engine ya got, mine's a 3.0 and it's a slight fustercluck to yank, but I'd seriously recommend you pull your alternator and take 'er in to a store for off-rig testing. Tell us what ya got.

By the by, eBay has HD VRs with pigtails for around $21, free 4-day shipping. I'm gonna run that. I took pride in keeping Gretchen bone-stock...but considering she's 24 years old, it's probly best to swallow my pride and convert it all. Ho, well...


Agreed. I wonder if the addition of lighting and/or an accidental shorting during installation could've kayoed the voltage regulator in the PCM. After all, our vans aren't spring chickens anymore.

Yes its also the 3.0. Thanks for all the info. I installed a new upgraded 120 amp alternator. I am up to 13.39V loaded. The battery is fully charged and tested good showing 12.99V. I found out the lighting was plugged into the 12v outlet so no way to screw that up. Turns out my son left them on with the van off and drained the battery. I have read multiple post that say these vans usually run 13.7 V. So that brings the question, is 13.39v close enough? BTW do you have a low voltage light on the dash after you installed the external regulator? I have seen some kits that include some thing you hook between the two wires from the pigtail.
I feel like the new alternator didn't really fix anything. I am thinking about returning it and replacing the pcm. $100 for a refurbished unit on ebay.

 

[BoiseVger]

Did you check your voltage with all electrical off? Loaded & unloaded volts are both important for basis of comparison.

Last September, I'd noticed my voltage was going below 13.5 and thought little of it until the battery voltage would drop if the minivan sat for more than a week. This stayed during my move from Boise to Kentucky but slowly became worse after the move, going to juuuust under 13 volts...and now the battery can weaken in a few hours.

I'm gonna run the external regulator; my repair design isn't invasive to the stock wiring and will still allow for a seamless install of a refurbished PCM later. Speaking of...$100 isn't bad at all, compared to a dealer-new unit! I had no idea someone could refurb 'em but $100 is out of my reach, being on a limited, fixed income. Plus urgency and owning a second car are driving my choice; I'll get a refurb unit later.

I do have an alternator light but it hasn't done a thing so far, even with the PCM regulator...not sure if the mod will affect it. It could...just can't tell right now. Of all the alternator failures I've ever had, only one in fifty ever tripped the light. Odd, huh?

Will the vendor accept your return? The vast majority won't accept returns on any electrical. See what happens...good luck!

P.S. -- My minivan uses a 90-amp alt, but that's typical to it having a single-zone heat/AC system and few options.

 

[willie101474]

Did you check your voltage with all electrical off? Loaded & unloaded volts are both important for basis of comparison.

Last September, I'd noticed my voltage was going below 13.5 and thought little of it until the battery voltage would drop if the minivan sat for more than a week. This stayed during my move from Boise to Kentucky but slowly became worse after the move, going to juuuust under 13 volts...and now the battery can weaken in a few hours.

I'm gonna run the external regulator; my repair design isn't invasive to the stock wiring and will still allow for a seamless install of a refurbished PCM later. Speaking of...$100 isn't bad at all, compared to a dealer-new unit! I had no idea someone could refurb 'em but $100 is out of my reach, being on a limited, fixed income. Plus urgency and owning a second car are driving my choice; I'll get a refurb unit later.

I do have an alternator light but it hasn't done a thing so far, even with the PCM regulator...not sure if the mod will affect it. It could...just can't tell right now. Of all the alternator failures I've ever had, only one in fifty ever tripped the light. Odd, huh?

Will the vendor accept your return? The vast majority won't accept returns on any electrical. See what happens...good luck!

P.S. -- My minivan uses a 90-amp alt, but that's typical to it having a single-zone heat/AC system and few options.

Glad you got yours fix. I have a battery/alternator/crank tester. I bought the alternator off amazon. They are usually really flexible with returns. I know a parts store wont take it back once hooked up. I got the alternator bench tested at advance auto and they said is was fine. I hooked it back up and am getting 13.27 Loaded, 13.68 unloaded. The battery by itself tested 12.89 I believe. I tried to ground the alternator and pcm case to battery ground. There was no change. I might just go your route. I hate to buy a pcm only to find out it didn't work and cant be returned. There is some white stuff on the connector. I scraped off what I could but couldn't get it all. I ordered a new pig tail. Worth a shot. BTW. I have done a ton of research. If you have any issues overcharging with this mod, connect a relay to the ignition wire and the battery. (something to do with voltage drops). Oh and if you every get an engine light you could wire a 194 bulb (license plate bulb) across the two wires that go to the pcm. It tricks the pcm.

 

[BoiseVger]

I was scanning eBay and Amazon just now: it seems someone has made a Chrysler conversion regulator kit which "bypasses the PCM" voltage regulator with 5 wires. It's very small and set for 14.7 volts...but here's the clincher: although it's meant to bypass the PCM, the sellers all warn it's "not to be used on cars with electronic fuel injection".

It makes no sense: cars with PCMs have EFI. And what does the alternator regulator have to do with EFI anyway? Weird...does anyone have an answer to this?

Meh, I'll stick with the other conversion.

Oh and if you every get an engine light you could wire a 194 bulb (license plate bulb) across the two wires that go to the pcm. It tricks the pcm.

I'm wondering if a resistor would be better. Bulbs blow out or get broken.

 

[willie101474]

I was scanning eBay and Amazon just now: it seems someone has made a Chrysler conversion regulator kit which "bypasses the PCM" voltage regulator with 5 wires. It's very small and set for 14.7 volts...but here's the clincher: although it's meant to bypass the PCM, the sellers all warn it's "not to be used on cars with electronic fuel injection".

It makes no sense: cars with PCMs have EFI. And what does the alternator regulator have to do with EFI anyway? Weird...does anyone have an answer to this?

Meh, I'll stick with the other conversion.


I'm wondering if a resistor would be better. Bulbs blow out or get broken.

That is strange. Yeah a resistor would be better. Anyone know the value and wattage required?

 

[Road Ripper]

I don't know why you'd have to trick the ECM, just bypass it. These vans (even newer ones up into the 2010's+) sometimes don't keep a high enough charge voltage. Maybe it could be the insanely hot engine compartment cooking the battery in the summer? The 2001 vans actually had a plastic heat shield between the battery and the engine to combat this issue (though it was omitted by the bean counters in 2002). That proves that Chrysler knew there was a problem and addressed it, then got rid of it for the sake of saving money.

Anyway, I bookmarked this thread a few years ago since it holds a LOT of useful information dealing with these charging systems and how to fix/modify them.

Cooling your Alternator and other things of note.

Getting more power at idle! High Amp alternators are plentiful out there. But as many of you have seen, some of these go for 500 bucks and fail to deliver. SO LETS SHOW YOU How to get more out of your stock machine that you got on there. 1. OVERDRIVE PULLEY Available at summit...

www.chryslerminivan.net

 

[guyonearth]

Yes its also the 3.0. Thanks for all the info. I installed a new upgraded 120 amp alternator. I am up to 13.39V loaded. The battery is fully charged and tested good showing 12.99V. I found out the lighting was plugged into the 12v outlet so no way to screw that up. Turns out my son left them on with the van off and drained the battery. I have read multiple post that say these vans usually run 13.7 V. So that brings the question, is 13.39v close enough? BTW do you have a low voltage light on the dash after you installed the external regulator? I have seen some kits that include some thing you hook between the two wires from the pigtail.
I feel like the new alternator didn't really fix anything. I am thinking about returning it and replacing the pcm. $100 for a refurbished unit on ebay.

Contrary to what you hear, there is no hard and fast number for running voltage. I've seen everywhere from 13.4 to 14.4. Temperature can make a big difference. A slight amount of resistance in the wiring or where you're checking it can make a big difference, and different tools can return different values. If it's over 13 it's charging the battery.

 

[BoiseVger]

I feel like the new alternator didn't really fix anything. I am thinking about returning it and replacing the pcm. $100 for a refurbished unit on ebay.

I looked on eBay and saw a person who offers repair of your original PCM for any problem, $95. Is this what you mean? This seems attractive, all things considered.

 

[willie101474]

I looked on eBay and saw a person who offers repair of your original PCM for any problem, $95. Is this what you mean? This seems attractive, all things considered.

No here is one you don't need to send in.
1997 Plymouth Voyager 3.0L ECU ECM PCM Engine Computer - Plug&Play - SALE | eBay

 

[willie101474]

Contrary to what you hear, there is no hard and fast number for running voltage. I've seen everywhere from 13.4 to 14.4. Temperature can make a big difference. A slight amount of resistance in the wiring or where you're checking it can make a big difference, and different tools can return different values. If it's over 13 it's charging the battery.

Thanks. I was kind of thinking that.

 

[willie101474]

I don't know why you'd have to trick the ECM, just bypass it. These vans (even newer ones up into the 2010's+) sometimes don't keep a high enough charge voltage. Maybe it could be the insanely hot engine compartment cooking the battery in the summer? The 2001 vans actually had a plastic heat shield between the battery and the engine to combat this issue (though it was omitted by the bean counters in 2002). That proves that Chrysler knew there was a problem and addressed it, then got rid of it for the sake of saving money.

Anyway, I bookmarked this thread a few years ago since it holds a LOT of useful information dealing with these charging systems and how to fix/modify them.

Cooling your Alternator and other things of note.

Getting more power at idle! High Amp alternators are plentiful out there. But as many of you have seen, some of these go for 500 bucks and fail to deliver. SO LETS SHOW YOU How to get more out of your stock machine that you got on there. 1. OVERDRIVE PULLEY Available at summit...

www.chryslerminivan.net

No need to trick the computer if you don't mind the voltage light on. That's the only reason.