Check engine light is on. Comes and goes
Seems to come on when using something electrical like cruise and voltage needle will fluctuate a little bit
Codes are 12 (batt connection distrubed) and
46 (charging voltage too high)
What do you do to fix this?
Thanks and cheers

 

high voltage will be a regulator problem, connection problem at the battery terminals can be the culprit

 

On a 92 where is regulator - built into alternator?
I did put new brushes in the alternator months ago so don't think the replacement is related to this check engine light
I'll check the batt connections
cheers

 

Update on the check engine light
When the light comes on (doesn't always come on), the voltage reading fluctuates (slightly)
One of my gear head gurus said it is a bad ground to the PCM
Thoughts?

 

PCM controls the alternator field, so that would be very plausible.

 

Update on this thread
I was chasing all sorts of wiring, grounds, etc
I was looking for love in all the wrong places
I happened to pull on the battery ground that goes to the block.
It came apart when I tugged. The wire came out of the connector
This was a one piece wire and connector (#2 gauge) purchased some moons ago from the local auto parts store
The lesson - start with the obvious, start at square one
Anyway my problem is solved.
No check engine light
No voltage needle fluctation
Cheers

 

Nice find, I think you got it ! That's a lot better than throwing an expensive PCM at it first and not solving the problem (which I've seen a lot of people do). Congrats.

 

Update to this thread.
The problem is back. Same needle fluctuation between the 2 and 3 mark (in that center group of 4 marks on the voltage meter.) And the check engine light is on. Same codes. Replacing the batt cables got rid of the problem for 10,000 miles later, it's back.
Rechecked the batt cables - tugged on them and they look good.
Any thoughts on what to do?
Cheers

 

Bump
Anyone?

 

Check the air gap on the crank positon sensor. It should be .050".

 

Thanks Philip
I'll recheck it. Was set at .050 but that was about 10K ago
Cheers

 

If it charges at all, the crank position sensor is OK. That turns on the logic in the PCM.

Boils down to bad connections, bad grounds, or bad PCM.

Check all connections, including the ones on the PCM itself. I've had old timers tell me that you should open up all the connectors, soak them in WD40, reset them several times, and forget harness problems for a long time.

Haven't done that (yet) but when I run into a sneaky problem like this one, the first thing I do is look up all the related connections in the electrical diagram, then detail those connectors with DeoxIT contact cleaner.

Regular spray automotive contact cleaner is mostly isopropanol, and leaves the contacts clean and dry. The old TV tuner contact cleaner would leave a protective lube on them. WD40 does the same thing. DeoxIT also leaves a lubricating film.

WD40, mostly kerosene, might raise Cain with the connector seals. Don't know for sure.

 

j martin
Thanks for the great info. I'll do that with the connectors, especially PCM
I always like to figure it out before replacing parts.
Cheers

 

UPDATE UPDATE
Once again, the problem was in the wiring contacts.
I took the alternator to a reputable electrical shop and the alternator is good.
I pulled all the wiring in and out of the alt.
Cleaned, filed, detoxes, etc and put back together
Fixed the problem. No voltage fluctuation and no check engine light. I'd rather find problem than replace parts.
Cheers
Jim