I have a 1989 240 DL wagon which exhibits the following problems:
When the key is turned to ON, only the yellow overdrive arrow light comes on the instrument panel. Pushing the OD button on the automatic transmission does cycle the light on and off. NONE of the normal engine oil, battery, or other lights come on. The bulbs check good with an ohmmeter. The car will start and run, but none of the gages register (speedo, fuel, temp, etc.); but the alternator does NOT put out any charge. I had the alternator tested at a local NAPA auto parts store; they advised replacement- which I did. It made NO DIFFERENCE. After driving it for approx. 15-20 minutes, the red BATT light comes on- and weakly flashes. Coincident with that, the speedo, fuel, and temp gages show some readout- but not a correct/ normal indication. The car wil shift in and out of overdrive- but the yellow arrow is ON when it is in overdrive (4th), and OFF when it is in 3rd- just the OPPOSITE of normal! What the hell is going on here?