The very first thing I would check is for clean and tight connections at the battery cables. Check both ends, ground etc. Also check the plug going into the alternator.
If nothing found,
There may be two problems happening. The gauge failure may the cluster itself going bad. From what I understand, the cam sensor is fairly common on these and ford has issued a new part for it. Was under recall I think.
Thursday, July 5th, 2007 AT 1:40 PM