01 Explorer Sport Charging problem

[Skrag55]

Just this weekend my battery gauge went down to nothing and the battery light came on. I had just replaced the alternator this April so I figured the part just gave out already. Went and got a new alternator under warranty and installed it on the vehicle. Upon starting it up I still have no charging voltage. I went to get the alternator bench tested and found that it is putting out proper charging voltage. I then started to inspect my positive cable and fuseable links to make sure none of those were damaged and none were. I was wondering if there is a alternator fuse/relay and if there is where it might be located. Thanks for any help in advance.

 

[joecrna]

Check the battery too.

 

[Skrag55]

Just replaced that a few months ago as well but I'll check it out with my DMM when I get out of work. I know it's discharged now because I let the vehicle run untill it died out to make sure my cluster wasnt reading wrong.

 

[Skrag55]

Tested the battery and it came out ok. I also cleaned off the terminals to make sure it wasn't to dirty. I have B+ voltage at the alternator cable and there is not a significant voltage drop across the positive wire to the alternator to prevent it from charging. I also have a good connection to ground.

 

[John_Rock]

Maybe check your grounding straps. There's one at the back of the engine connecting to the firewall. And there's one underneath the truck connecting the frame to the body(mid body).

 

[Skrag55]

Would there be any more grounding straps I should be looking for. When I get out of work I'll check those two locations and see if there is a brake or corrosion at the grounds. I was also wondering if the gauge on the instrument cluster could be causing a no charge condition, as if it might be inline with the alternator so if its not reading properly it would cause the alternator not to kick on.

 

[tripplec]

Guages

What about all the other guages, are they reading normally? Is this only a problem with the Battery guage? Warning lights turn on with ignition turned before starting? I would think that all instruments have a common ground to the panel and not independent but I don't have service manual. I have been looking to download one but have yet to find one for the Sport.

 

[Skrag55]

Yes all the other gauges read normally. I checked my grounding straps and all were good. Battery cable ground was good as well. I'm getting voltage to the signal wires of the alternator. I just dont know if they are reading right because both had B+ voltage. I need to find a wiring diagram to figure this out.

 

[tripplec]

Dash

Yes all the other gauges read normally. I checked my grounding straps and all were good. Battery cable ground was good as well. I'm getting voltage to the signal wires of the alternator. I just dont know if they are reading right because both had B+ voltage. I need to find a wiring diagram to figure this out.

No offence but you're looking in totally the wrong area. If you had a starting, charging or voltage drop issues to the vehicle as a whole then the battery connections and alternator test you are doing would be correct.

However, regardless of the voltage level the battery guage would read something (you say it is not correct, Zero or not moving) then there is no power reaching the gauge. I asked if the other gauges were all ok and normal and you confirmed. Power to the gauge through one of the harnesses is not reaching the dash and finding that would be a challenge. It could be a corroded contact somewhere or broken wire. Lighter socket have separet circuits as do other devices and all going through the power distribution fuse panel. If the fuses are all good then its wiring and/or contacts. Unfortunately the dashes are never easy to get at(rear for testing or bulb replacement). Get one of those 12V probe testers which has a light in the handle and goes through all the fuse test contacts and see if their is a dead one or corrosion at one of the fuse ends if you can locate the fuse which powers the dash. They are low impedance unlike digital meters and place a milliamp load when testing and its much faster to visually see.

The gauge might even be at fault and you'd never know. You'll need some precise test points and getting a service manual with the wiring layout is likely the only way. Something like a Haynes manual would help.

good luck