1987 RX-7 battery discharging while motor is running and car is being driven?

KSCONNELL

MEMBER
1987 MAZDA RX7
108,000 MILES

Battery charges fine and starts RX-7 perfectly on the first attempt after charge.
Drive the car 2 miles and turn off ignition -- starts very weakly after short distance.
Drive approx 6 miles and turn off ignition and car will not start again, only hear starter sounds? Additionally, when start is weak the steering seems to become stiffer as the distance increases?
Battery leads are not corroded, posts were cleaned when this happened on Saturday.
Thank you

1 Reply

JACOBANDNICKOLAS

MECHANIC
108,328 POSTS

Okay, the idea that the steering gets harder leads me to believe the belt may be slipping. Check that first. Make sure it is tight and not being contaminated with oil or coolant. Next, use a volt meter to check the battery output with the engine off. Then start the car. The voltage at the battery should go to aprox. 14+ volts with the engine running. If it doesn't, have the alt checked first. If the alt checks good, check the fuseable link between the alt and the battery.