85 740 GLE

The alernator light and the EGR light stay on all the time in my car. I have checked the charging voltage and it is about 14 volts. Same with headlights on.
The red lights come on with the ignition and never go out after starting.

The alternator seems to be charging fine but something must be bad between the alernator and the instrument panel or perhaps a ground is bad.

Any ideas? Cars of this year had insulation problems with the harness.

Thanks, Steve

I have the 89 740 wiring info- whats the EGR light?

The alternator idiot light runs from the D+ line from the alternator.
If you're charging 14V it must be OK
I'd suggest that you pull the instrument cluster and reseat the
12 pin connector, maybe it's loose or dirty or cocked?

Bill

Thanks, I will try re-seating the plugs. On some charging systems the red light has 12 volts on both contacts so it goes out when charging properly.

The EGR is only on diesel models I guess. Charging system is the same however.

Steve

The charging light is in series with The alternator D+ line through the
ignition switch pin "15R" back to the + battery terminal.

1.You might remove the D+ from the alternator and with the ignition off
see if you find any resistance to ground.
2. Remove the + battery terminal and try again same test with
ignition switch ON .... checking for a funky ignition switch

It must be a bad wire or switch that became a resistor to ground,
or perhaps a dead diode in the alternator?