bad belt

[joey zingale]

Can anyone tell me if a worn belt can give the same or similar symptoms as a bad alternator?
I had what I thought was a bad alternator checked at carquest while it was on the car, it was only putting out 11.4v
I now notice that i have a badly worn belt.
Tach not working but the alt./battery light is no longer comming on.
this is a 97 discovery
thanks

 

[Maddie]

Sound to me like a bad alternator. The idiot lite ( and that is just what it is) won't always lite up. The tach is driven by the alternator. In fact a tried several new cheap alternators neither of them would drive the tach. I suppose the belt could be slipping if it's badly worn I suppose one could change it first but my money is on a bad alternator. Another thing to look at is the markings on the idler pulley if it's past the marks the belt is streched too far and possibly slipping however the serpintine belt has an awful lot of grip and if slipping will make alot of noise.

 

[Disco Mike]

A bad belt as well as a warn belt tensioner can cause low voltage but you'll also hear some belt squeal.
Be real careful where you buy a new or rebuilt alternator, lots of cheap rebuilds on the market that don't last.

 

[joey zingale]

bad belt / low voltage

Thanks
I am not getting any squeeling, but I have changed out the alternator. I had the alternator tested while on the vehicle, that showed a low voltage reading, got another alternator, same problem. I ordered a new belt ( not here yet) from atlantic british. I will have the alternator tested off the vehicle.
I will let you know how this one turns out.
thanks

 

[joey zingale]

Well the belt is in poor shape, but when I installed the new alternator, I got the route for the belt wrong. After installing the belt correctly all is good. No alt. light, tach is working fine, and most importantly, the battery is charging.
Thanks for the help!

I hope someone here can learn from my mistake.

 

[Maddie]

Hope it's a bosch alternator. The oem's last exactly 45,000 went thru two before I went with Bosch. I'm still cruising with over 55,000 on it. Checked it this am and am still at a whopping 14.6volts with lites and such on.

 

[disco13]

Last year I went through 3 alternators before I got one that lasted. They kept testing fine at the parts store but they were just barely passing the test. But then on my way home the tac would drop out or start to bounce. I have been told that if your alt. goes out to replace the battery as well. The last alt I got I did replace the battery at the same time and havent had any problems with that since

Troy