99 mountaineer charging problem

[tooboyzmom]

Help! My dash gauge is showing discharge. The lights dim then the vehicle won't start (unless jumped) after a short night ride. I've had the alternator and battery both checked (multiple places in case the testing system was faulty) and both are good. Any ideas where to go from here???

 

[imp]

Insides of battery terminals clean, where they "grip" the battery posts? Common cause of start problems, even though low-current draw accessories work, like lights, horn, etc. If terminals have inadequate clean contact area, something called "current density" prevents the current from flowing through the dirty or burnt area. imp