1989 Le Barron AMP Guage goes past 18 check engine lite

I have a 1989 Chrysler Lebaron convertable with (a 2.5 LTR turbo, automatic
trans). I just purchased this car and found all kinds of problems, but for
the most part I have fixed them. The one problem I am having that I can
not fix is the voltage regulator, I have been told it has a internal
voltage regulator, I have been told it has an external voltage regulator,
and I have been told the voltage is regulated from a (SMEC, single Module
Engine Controller). Could you please shed some light on this, and let me
know where the voltage regulator (in the alternator, external, SMEC) is
located.
Thank you SO much.
Mark

 

Neither is correct.

Correct, the voltage regulator is built into the SMEC. This voltage
regulation issue is the most common SMEC failure (which is not to say it's
very common; Chrysler's modules tend to be pretty durable -- just that
this particular failure is usually how they fail.) The official fix is to
replace the SMEC.

Here is a much less costly fix that *will* work, without replacing the
engine computer and without causing any additional problems:

First, pick one of the following regulators:

Regular normal electromechanical regulator:
NAPA Echlin VR32

Extra heavy duty electromechanical regulator w/vibrationproof mount:
NAPA Echlin VR34

Extra heavy duty electromechanical regulator w/vibrationproof mount and
convenient external voltage adjustment screw:
NAPA Echlin VR35, Standard-Bluestreak VR106

Transistorized regulator with no moving parts (no adjusting screw):
Standard-Bluestreak VR101, Wells VR706 (the wells item is very
inexpensive; it works but Wells doesn't make my favourite stuff)

Waterproof potted IC regulator with no moving parts (no adjusting screw):
NAPA Echlin VR1001, Standard-Bluestreak VR128

Any of these regulators will have two terminals on it, one marked "IGN"
and the other marked "FLD". (the VR1001 and VR128 have the "fld" terminal
on the end of a short wire lead). The alternator gets the original field
wires removed from its two field terminals (right next to each other,
small studs with nuts retaining the two flag terminals -- be careful not
to break off the studs!).

The regulator IGN terminal gets 12V via the ignition switch, and the "FLD"
terminal gets connected via a wire to one (either) of the field terminal
studs on the alternator. The other field terminal on the alternator gets
connected via a wire to ground. Run a ground wire -- 16ga is plenty --
between the regulator base and the battery negative terminal, and mount
the regulator such that it won't rock 'n' roll around. At this point, your
charging system will once again work fine. If you got the adjustable
regulator, set it for 14.2v across the battery with the engine fully
warmed up and idling, no lamps or other accessories on, and ambient
temperature above 50F.

If your "Check Engine" light comes on, put a resistor across the two
original field wires that you removed from the alternator, before securing
these wires such that they can't ground out or get caught in any moving
parts.

Close the hood; you're done.

DS

 

I feel so much better, I was thinking along these same lines (re-direct
voltage regulation via a external regulator) but this is awsome with the
part numbers... It sure beats $300.00 for the SMEC unit. And it sounds a
little fun.
Thank you so much.
Mark