I recently went for a car inspection test after having a new battery and radiator in my car, when i got there the shop man told methat i would need to drive around for about ten more hours so that he could get a proper reading, i decided to drive back home because i didnt believe the car on the road for ten more hours would be a good idea. well on my way home all of a sudden i noticed my car wasnt moving, at the second light silence it had turned off, i knew i needed a new alternator, but didnt think that after five hours of driving i would get stranded a few blocks from home luckily i was able to get a boost back home. When i got a few blocks from my home i decided to gun it so it wouldnt turn off again, but when i get a pass twenty miles an hour i noticed the the spedomter was moving by itself going up to forty miles an hour and then back to ten while the car was maintaining the same speed. My question is would a car that needed a new alternator have a dashboard, reading improper speeds and have the needle shooting all over the place, or would it be a different cause???
“i knew i needed a new alternator”
Hmmmm…and you assumed that you wouldn’t you wouldn’t “get stranded a few blocks from home”.
Actually, I sort of agree with you. I would assume that it was more likely to be stranded far away from home.
In a roundabout way, I am trying to get the point across that driving a car with a failing alternator is just not a good idea. Besides the obvious point of possibly being stranded in an inconvenient place, at an inconvenient time, you have to consider that virtually everything on a modern car is an electronic device. Electronic devices (like the Vehicle Speed Sensor that sends information to the speedometer) are extremely sensistive to fluctuations in voltage, and a failing alternator will have inconsistent voltage output.
I would suggest that you stop gambling on that alternator and get it replaced. If you don’t do it soon, you will probably wind up killing the new battery, and may actually do some damage to various electronic systems of the car. In other words, you will not save any money by deferring alternator replacement, and you may actually wind up paying more in the long run.
Ditto. Well said.