99 Auto P or N to D or R Stalls

[Joe Mc]

Personally, I would not do this test in the manner stated. I am assuming that the driver side battery was still disconnected when you disconnected the passenger side battery and the engine died. If this is the case, the alternator would immediately lose the stable voltage from the batteries and this disruption would likely cause rapid voltage spikes throughout the electrical system. Electronic components do not like this. It was probably fortunate that the engine died.

If I wanted to isolate the alternator as a potential problem, I would take the alternator out of the loop by disconnecting the field connector and the output wire on the alternator. Then I would start the engine to see if any of your symptoms have changed.

- John

John, I didn't know this thsnks.
Papa, also didn't know. In past with non-our type trucks I've had 2 cars 1 battery started car 1, removed battery put in car 2 and moved cars as needed. No problem. Won't do this on my truck again thanks.

 

[Joe Mc]

I would do exactly as John stated and disconnect all wires to the alternator if you want to check that.

Here are a couple things I'd suggest - some you already might have tried:
- check/monitor voltage when running.
- check for voltage drop.
- check grounds - a bad ground should be seen via the drop test, but won't hurt to double check and visually check all ground locations.
- computers prefer straight DC, so use a scope to check for "noise".

Dan

Dan, thanks I'm not 100% sure on how to do voltage drop test. Should you wish to reply please do so via PM so as not to clutter (no offense intended) this thread. Thanks

 

[Joe Mc]

Looks like Oz and I agree.

ALso AC would be "noise" - indicating a bad diode(s).

All I can say about alternator test performed is I took it and watched it being tested and it came back good.

 

[Joe Mc]

BTW: Not that it matters, I guess?, but I disconnected batteries as follows driver positive "then" passenger positive.
Also, I posted on other forum, where suggested to disconnect while running, that I found out a no no and why. Just in case someone else down the road saw suggested test wouldn't give it a try and try everything. Hoping I didn't because at this point if I did I'm so ticked off and frustrated I might grenade it. Stepping away for now...

 

[DavidC]

FYI
Does a car alternator produce a pulsating or clean DC?



It generates 3 phase power that is rectified into dc.

It is not clean DC but the battery acts as a large capacitor so the battery should not be disconnected from a running car to protect the ECU

 

[Ozymandias]

All I can say about alternator test performed is I took it and watched it being tested and it came back good.

It's easy to do, start engine, high idle, take your Multimeter, set it to AC, measure about battery poles. Read result.

*they don't do that test commonly, it can test good on the bench but be faulty anyways.

 

[SnoKing]

Have not followed this completely, however is there a chance the VP-44 was installed out of time?

 

[DavidC]

It's easy to do, start engine, high idle, take your Multimeter, set it to AC, measure about battery poles. Read result.

*they don't do that test commonly, it can test good on the bench but be faulty anyways.

General consensus is to check at alternator for AC ripple as the batteries can absorb some of that and give a false reading. Some also state to turn on every accessory you have and others state to not run anything but the engine to have a level play field as different vehicles may have different options that could skew the readings from the known standards. AC ripple can play havoc with electronics and may eventually burn them out.

 

[DavidC]

Have not followed this completely, however is there a chance the VP-44 was installed out of time?

Highly unlikely as the symptoms are the same as before the change.

 

[BigPapa]

Have not followed this completely, however is there a chance the VP-44 was installed out of time?

Yeah, I thought for a minute maybe the new IP had the wrong key until I realized it was doing it with the old IP, too.

 

[Joe Mc]

the battery should not be disconnected from a running car to protect the ECU

I understand = no disconnect batteries with running. Sorry but everything else is over my head. Thanks for support.

 

[Joe Mc]

It's easy to do, start engine, high idle, take your Multimeter, set it to AC, measure about battery poles. Read result.

*they don't do that test commonly, it can test good on the bench but be faulty anyways.

Ok, so get started, multi meter set to AC connect meter to battery, + to + and - to - increase idle and meter should read? Thanks

 

[Joe Mc]

Have not followed this completely, however is there a chance the VP-44 was installed out of time?

Can't see how since crest/½ moon key supplied with pump is specific for that pumps timing. Unless I'm totally out in left field. That

 

[Ozymandias]

Ok, so get started, multi meter set to AC connect meter to battery, + to + and - to - increase idle and meter should read? Thanks

Yes, should read less then 0.1V, best would be 0.03V or less.

 

[Joe Mc]

General consensus is to check at alternator for AC ripple as the batteries can absorb some of that and give a false reading. Some also state to turn on every accessory you have and others state to not run anything but the engine to have a level play field as different vehicles may have different options that could skew the readings from the known standards. AC ripple can play havoc with electronics and may eventually burn them out.

Once again not ashamed to say "AC ripple" way over my head. Electronics are my very weakest point. Thanks

 

[Joe Mc]

Yes, should read less then 0.1V, best would be 0.03V or less.

Thanks Oz, that I can do with my Fluke Amp clamp/multi meter. If i get a clear weather spot and after reinstalling alternator, if i didn't try everything, and it starts I'll give that a try.

 

[DavidC]

Here you go Joe, one of many
https://mopar1973man.com/topic/13280-ac-ripple-testing/

 

[DavidC]

These are some numbers I have found over the years

0.00 VAC is PREFECT DC power. This would be with the truck not running at all.
0.01 VAC Excellent (Rare to see)
0.02 VAC Still really good
0.03 VAC Good
0.04 VAC Good
0.05 VAC OK but marginal
0.10 VAC Failed.

 

[Joe Mc]

Thanks David.
Interesting info.
Wish my trans guy was more of a diagnostician and was able to figure this stalling out.
At this point I'm running in circles banging my head at every ¼ way round the circle.
I dread throwing my hands up and giving the dealer a crack at it. You know "it's too old"... Just at a total loss as to why it ran fine (outside of exhaust hazing more than ever) right up to post freshened up injector install??? At least it doesn't haze now...

 

[DavidC]

One step at a time Joe. Don't get frustrated, consider it a battle and be determined to win.