86 Lebaron 2.2L turbo battery is overcharging

[bobbynjodi]

My daughter bought an 86 Labaron convertible for $350.00. It runs well w/ 160K miles on it. Suddenly...after she installed her stereo the battery began boiling water out. The guage shows 18 volts at cruising speed and often in the middle of the guage at idle. I replaced the alternater, no joy. I swapped out batteries, no joy. I read the post about the SMEC possibily being the problem. I wanted to avoid spending limited resources on a probably...$85.00
What is my best course of action? I thought about installing the external regualtor $15.00...looks complicated.
Any help you can give me would be appreciated. Bobby

[88 aries]

im not a fan of aftermarket crap, you should find a chrysler CD /tape player from a dodge neon or any other newer mopar.

they work just as well as an aftermarket, im a fan of originality, i own 3 K-cars and know them inside and out.


the radios that fit are, 84-99 any chrysler stereos.

[Butch]

If the alt loose's it's grd it will overcharge, the 86 doesn't have the SMEC. It's a LM/PM ECU control. The external reg. is a good idea if the LM/ PM is at fault. Here is a write on how to do it.....http://www.turbo-mopar.com/forums/vbart ... ticleid=51 Reg. on TM as there's alot of other mechanic's on there.

[bobbynjodi]

Awesome post. Thanks. My alternator has more than just two posts...
I will look up the brand to see if I can get a diagram.

[Hemi-Dude]

Awesome post. Thanks. My alternator has more than just two posts...
I will look up the brand to see if I can get a diagram.

The alternator in the diagram is a 3 post model. The unmarked post at the bottom right is the output (12V BATTERY LEAD) Where the power comes out to the battery.
The 2 posts with wires to them are the field posts. One receives IGNITION SWITCHED battery voltage. The other is the return wire to the regulator which controls the amount of circuit ground in order to regulate the alternator output.

[bobbynjodi]

I gave in and bought the SMEC. It worked and now the car is not overcharging. Autozone...had it.

Thanks for your help.

[84reliantk]

That is very strange that after putting the CD player in, you would think the alternator would not be able to keep up, not over charge. with my 84, i put a sound system in it, and the alternator burned out, it couldnt keep up with the demand, i had to put a bigger alternator in it. but thats good you got your problem fixed!