maybe the alternater shot
Asked by oledog56 Aug 28, 2013 at 08:12 PM about the Jeep Grand Cherokee
Question type: Maintenance & Repair
replaced the battery in my 1997 jeep instrument panel died ..changed fuse all works ...now the voltage part goes up to normal at the start up then dies down to 0 check gauges light comes on and digital thing says check battery...is this the alternater if so how I do I check this I do not own an ohm meter
7 Answers
thejeepdoctor answered 11 years ago
Well, you will at least need a test light. charge batt. then you unplug the connector from the alternator. Then hook leed from test light to neg side of battery, then start vehc. and then ck. for power at the alt. connector. it doesnt matter which wire you ck. wont hurt anything. It light lites up, then hook leed to pos. side of batt. and test other wire in connector. if light lights up....the alt is bad. the ASD relay provides power to the field of alt. PCM controls the ground side. DO NOT SHORT THESE WIRES IN CONNECTOR TOGETHER...may ruin PCMs ability to control alternator.......hope this helps.....
thejeepdoctor answered 11 years ago
Also ck. to make sure you have battery voltage at the big red wire at back of alt.
thejeepdoctor answered 11 years ago
does batt. go dead as it goes to 0 or does it just quickly drop to 0?
no battery is brand new it just quickly drops to 0
the battery stays going as I am able to still drive around just no volts on gauge....had an alt go years ago on another car....would just die then a quick boost and go a bit more then die tis hard on the battery
thejeepdoctor answered 11 years ago
you might goto autozone and have them scan it. charging voltage should be just below 14 vt. if SCANNER says 14vt then you have a gauge issue, as this info from the PCM is bussed info. to the cluster.
thanks or the help thejeepdoctor ...do you think I could have been getting wet from anti freeze spraying on it just replaced thermostat housing because of a leak it has sat for 2 weeks til I fixed it started it up and the gauge works again...does a bit of squealing now and then but at least it works