Re: strange electrical problem
There is continuity in the entire charging circuit as diagrammed in the Haynes manual.
I performed the charging system check in the Haynes manual, which lead me down the "under voltage" check. All the tests passed except the last test, which I didn't do because the action to take after the last test is to replace the alternator regardless the result of the test.
There was 13 ohms between negative terminal and alternator housing, but I hooked a jumper wire from the negative battery terminal to the alternator housing and no effect.
None of the fuses are blown.
The positive battery terminal was heavily corroded. I replaced it, however it looks the the corrosion goes at least several inches into the wires.
Now here are more details of the problem:
- Turning on the lights/fan cause the battery indicator to drop.
- Coming to a stop causes the battery indicator to rise.
* pushing the clutch in while the vehicle is rolling does not cause the battery voltage to rise according to the battery indicator
- The voltage across the battery terminals drops when the engine is revved by about half a volt according to my DMM.
- There is 0.22 A being drawn while the vehicle is off (including all lights). That seems reasonable.
- The problem is still intermittent. It occasionally "clicks back in" and everything seems normal.
- When the problem is there, the oil and temperature gauges behave very unusually. The oil gauge will read slightly high and flutter occasionally, and the temperature gauge will read high - often it will climb high enough to turn on the warning light and then come down to normal in about 30 seconds.
- The vehicle will run with the positive lead disconnected from the battery (although its pretty rough and the battery indicator will read pretty low).
- The serpentine belt appears to be good (no cracks/splits/damaged ribbing).