[Yeahrightgreer]

Good afternoon guys - this is my first post here, looks like a lot of you guys are pretty knowledgeable on these Turbo Era Dodges. This is my first G-car. Im a huge C-Body Mopar guy and all of my knowledge of cars is limited to 65-73 Chrysler products.

The car is an ‘86 Daytona Turbo Z. I bought it last Saturday. The car has 50,100 miles on it. I bought it from the owner in Somersworth, NH who had just drove the car through the latest HotRod Power Tour last month. For him the car drove perfect.
After I bought the car, I drove the car from NH down to NC a 900+ mile journey. About 400 miles in, around Baltimore, I was pacing a ‘19 Charger (I know bad idea) and I guess for a moment when I hit the car at WOT I felt the turbo cut out and the alternator stopped charging.
There was a visible loss of power for a few minutes, which then after it returned, and the alternator charging returned. Sometime after that In the next 50 miles the alternator stopped charging and the car only ran off the battery. I made it until about the NC line, about 700 miles into the journey when the car completely lost all power. Thankfully I had a friend in-trace behind and was able to charge the car.
I switched the power module when I got home with another (not new) to see if it was the voltage regulator and it made no difference. I jiggled a few wires and connectors to see if it was a loose connection. Finally decided to change the alternator, bought one from advanced auto and BOOM it worked perfectly. It was the original so I didn’t give it much thought. This was Thursday.
I took the car for a a 160 mile drive, and about 100 miles in on the return trip - alternator stopped charging. Made it back home, checked the multimeter and the output is at 11.76V

So now it’s been about 7 days and I’ve gone through 2 Alternators. I know sometimes even new alternators and be crap especially if their made out of Chinesium but really? What else should I be looked for? A short?
I’m not too electrically savvy so assume that I know NOTHING.

Thanks in advance guys,
Greer

 

[tryingbe]

Take the alternator back to advance auto and see what they say about the alternator.

Were the pos/neg wires getting hot when the alternator is working?

 

[Yeahrightgreer]

What do you mean getting hot? Do you mean physically? Or as in it is in fact charging? After installing the new alternator I hit it w/ a multimeter and it was getting up to 16V and charging at around 14-15V

 

[tryingbe]

If the charging cables were hot, then the resistance of the cables are too high and the cables need to be changed.

But, if if the system charges at 16V, then your voltage regulator isn't doing its job. It's common for them to go out and people usually replace it with an external voltage regulator off a dodge truck.

https://www.ebay.com/i/163622983492?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=163622983492&targetid=543737960846&device=c&mktype=pla&googleloc=9030021&poi=&campaignid=1497308096&mkgroupid=59509629482&rlsatarget=pla-543737960846&abcId=1139476&merchantid=114759429&gclid=Cj0KCQjwyLDpBRCxARIsAEENsrILEl3mtbwYow7SbChB2sif1Y2eui5OapSc-RcX3rU-fyGfF8ILqfEaAtlVEALw_wcB

 

[NAJ]

Welcome To TD!!!

From what I am reading, each time the alternator fails it fails in a "no charge" state.
If this is correct you need to diagnose the issue with the faulty alternator installed.

Next time the unit fails Before disconnecting the battery check for any stored fault codes.

https://www.turbododge.com/forums/f4/f14/362173-obd1-codes-retrieval-chrysler-1983-1995-a.html

Are there charging system faults stored in memory?

I will send you charging system diagnostics and wiring through PM.

Any questions/comments feel free...

 

[Dr. Johny Dodge]

well there's the diagram with the screw -ie third wire to "ignition source" again

you DON'T need that
simply connect the two field wires from the alternator to the external regulator and bolt that to the strut tower

best place is the driver's side strut tower
then you cut the field wires where the engine harness connects to the compartment harness behind the battery
make your cuts on the compartment side of the harness connector so that you can disconnect the harness as usual later if you need to remove it for some reason

again, you need ONLY connect the two field wires as shown
and it doesn't matter which one goes to which terminal

I've done it this way 6 times now without ever having an issue
you DO NOT need the ignition source wire ..DISREGARD

and cut the wires , don't splice into them and leave the ends still connected to the pm

 

[Yeahrightgreer]

I will check it later today, I havent disconnected the battery yet. Just turned off the vehicle. I checked the codes last time and I believe the only thing it told me is “Low Voltage Detected, System not charging” something along those lines. Maybe code 46??

If the alternator has failed how am I able to properly diagnose it? At least to be able to tell if it’s the regulator or not? I saw it charging at 16V so I thought it was a little high but it settled down. I didn’t hit it with a meter after that. I’ll definitely try and bring the alternator back to AA tomorrow after work.

What is the third wire for then? Is it for a more complete circuit?
I’m so familiar with the 1970 and up electronic voltage regulator so I may just mount an external one. It seems having to replace a power module every time it goes out would be troublesome. Does any VR from that era work? I have a few laying around and connectors for older Mopars. Just don’t know if anything changed in the regulator from 1970 to 86.

Thanks for all the help so far guys

 

[Yeahrightgreer]

I will check it later today, I havent disconnected the battery yet. Just turned off the vehicle. I checked the codes last time and I believe the only thing it told me is “Low Voltage Detected, System not charging” something along those lines. Maybe code 46??

If the alternator has failed how am I able to properly diagnose it? At least to be able to tell if it’s the regulator or not? I saw it charging at 16V so I thought it was a little high but it settled down. I didn’t hit it with a meter after that. I’ll definitely try and bring the alternator back to AA tomorrow after work.

What is the third wire for then? Is it for a more complete circuit?
I’m so familiar with the 1970 and up electronic voltage regulator so I may just mount an external one. It seems having to replace a power module every time it goes out would be troublesome. Does any VR from that era work? I have a few laying around and connectors for older Mopars. Just don’t know if anything changed in the regulator from 1970 to 86.

Thanks for all the help so far guys

 

[Yeahrightgreer]

Just checked the diagnostic codes. Still not charging.

41 - charging system circuit not responding to control signal, alternator field circuit not switching properly
45 - turbo boost limit exceeded-map sensor detects overboost
46 - battery voltage too high..overcharging

It seems like both failure scenarios, though it may not have been caused entirely by, have both been during situations where there was overboost .

 

[NAJ]

Quick question...
You stated that you tried another PM, was that tried after the alternator died and it still would not charge or was it installed while the system was still charging normally and the problem was still present and the alternator still failed?

Did you receive the PM with the wiring and diagnostics?

If the problem happens during "overboost" then perhaps you should diagnose the overboost issue first.

The issue could be related to the vacuum system, wastegate solenoid or wastegate.
Another PM being sent.

 

[Yeahrightgreer]

So after the Initial, original 33 year old alternator failed, Alternator #1, I switched the PM with an old one laying around (PM #2) to see if that would help the alternator.

Now note - I couldn’t and cannot confirm that PM #2 was good and serviceable. I just know the previous owner replaced it because he knew it was old and while he was replacing most electronics, didn’t want anything failing. He gave it to me as an extra. I guess it’s possible PM #2 was not serviceable.
After I saw that it did not make any changes to the charging system, I replaced the alternator, w/ Alternator #2 where it started charging, but as I’ve now realized, overcharging.
Sorry if I’m making it a bit confusing.

I received your message, thanks you. I know the basic fundamentals of turbocharging but I have absolutely no idea how the system works so it’ll he something I have to study tonight. I know the factory boost limit is suppose to be 7PSI? The car gets up to 10 or even 14, I have to feather the throttle to make sure it doesn’t get that high

 

[NAJ]

So you are overcharging with a new alternator and PM, run the Code 41/46 diagnostics and see where it leads, this will tell you if the problem is the PM, a shorted field wire or faulty alternator.

The engine controller does not see Overboost until you are over 14.5 lbs of boost which is 2 Bar and then it will go into Overboost Shutdown until boost levels are below the 14.5 threshold and it will continue doing this as long as overboost continues.

FYI...
Although overboost shutdown is designed to protect the engine from going lean overboost shutdown is very hard on the engine and can cause headgasket failure and/or breakage of piston ring lands so you want to avoid it at all costs.

Again, in case it was lost in the messaging.
Wastegate stuck closed or no pressure signal to the wastegate.

If you can borrow a hand held vacuum/pressure pump you can apply pressure to the wastegate directly and through the line from the wastegate solenoid to see if the wastegate opens.

VACUUM/PRESSURE PUMP
https://www.tooltopia.com/mityvac-mv8500.aspx

RESULT OF CONSTANT OVERBOOST

 

[Yeahrightgreer]

...

 

[Yeahrightgreer]

So you are overcharging with a new alternator and PM, run the Code 41/46 diagnostics and see where it leads, this will tell you if the problem is the PM, a shorted field wire or faulty alternator.

The engine controller does not see Overboost until you are over 14.5 lbs of boost which is 2 Bar and then it will go into Overboost Shutdown until boost levels are below the 14.5 threshold and it will continue doing this as long as overboost continues.

FYI...
Although overboost shutdown is designed to protect the engine from going lean overboost shutdown is very hard on the engine and can cause headgasket failure and/or breakage of piston ring lands so you want to avoid it at all costs.

Again, in case it was lost in the messaging.
Wastegate stuck closed or no pressure signal to the wastegate.

If you can borrow a hand held vacuum/pressure pump you can apply pressure to the wastegate directly and through the line from the wastegate solenoid to see if the wastegate opens.

VACUUM/PRESSURE PUMP
https://www.tooltopia.com/mityvac-mv8500.aspx

RESULT OF CONSTANT OVERBOOST
View attachment 254785

Hey mate, thanks a ton for the diagrams. Sorry for the late reply as I haven’t been around the car much. I fixed the overboost issue this morning. At some point the previous owner confused the 2 wastegate solenoid hosed. The manifold pressure hose was connected to the wastegate and vice versa. After tinkering for a bit with a vacuum gauge, noticing it, and correcting it, the car seems all good and is limiting boost again.

In terms of alternator, after replacing it again from Advanced Auto under a defect item, there hasn’t been any more voltage loss and has been charging pretty good now.

Hopefully the overboost that has happened, hasn’t caused significant internal damage. I guess only time will tell. Thanks again a ton