I have a 99 f150. Manual transmission with the 4.5.
when I'm driving the battery gauge needle goes straight up to H.
I just had the alternator checked at my local shop and everything read good. They said probably just a faulty gauge.
how do I fix that?

 

Did the needle jump fast or did it crawl up. If it moved fast it may be a wiring/connection problem. If it moved slowly it may be a gauge problem.

Put your cluster in test mode and see if all the gauges sweep properly. You may have to pull the cluster and inspect the wiring for any damage or loose connections.

 

it doesn't do it right away. After about half hour or so it jumps right up. Put it in neutral and coast it comes back to where it should be.

 

Does it only do it once or does it randomly repeat ?

 

once it starts it does it til I shut it off

 

today it's completely dead. Yesterday everything checked out fine

 

Did you perform the cluster test

 

got my truck ithe shop now. They say that something is draining the battery so they are going through it. I don't have all the equipment to do it myself. I will Merion the cluster to them