electrical gremlins. Codes 41 & 47?

[JeremyL]

Can someone enlighten me on why I'm getting a code 41 & 47? I've run over the wiring & everything appears okay. I can put a meter on the battery terminals & it appears to be charging normally (13.7 volts no load). I have noticed that it appears I do have a voltage/possible ground problem but I have no clue where to look.. Doing things like turing on the headlights, flicking the window switches, and even turning the turn signals on makes the hum of the fuel pump change. In fact if you turn the signals on it changes in relation to the flashes. However with a meter on the battery there's no fluctuation there. Any ideas? I'm guessing theres some corrosion somewhere, but for the life of me I don't know where it's at.

[GLHS444]

My 86 GTS was having some electrical issues a few years back, maybe the fix to my problem may help you.

Although I was not receiving any codes, I could not get any of the digital eguipment in the car to keep from going into a light show from time to time.
What I discovered was that I had a nasty AC voltage ripple on top of the DC signal (did this by monitoring the voltage at the cig lighter connection ). It caused overcharging issues, and strange actions from the ECU on top of the laser show.

After alot of testing, it turned out to be the positive lead right at the battery post. The original + battery terminal had a poor connection inside of it. The lead that was faulty was the one running from the alternator to the battery. This circuit feeds pretty much everything other than the starter and harzard lights. With the poor connection inside the + battery cable terminal, the majority of the voltage and current for the car was pure alternator voltage, hence the 2.5V to 4V AC ripple on top of the 13VDC signal.
Once I fixed this, all my electrical issues cleared up.

Hope this helps.

[JeremyL]

I'll run over all the connections again, and possibly replace the positive lead. I think I still have some left over terminals from my car audio days. Thanks!