96' Ranger 4x4 3.0 XL

While driving home from work I noticed the battery light had come on and the battery guage was maxed out. I immediately drove to the parts store. The test determined the voltage regulator had gone. I bought a new alternator and installed it and this didn't fix the problem. The battery is supplying what it can. Not quite 12v but it's been kept on a trickle charger. Pulled every fuse I can find in my frustration and everything checks out. I made it back to the parts store yesterday had the "new" altenator tested and it came back without a problem.

 

Verify the charge indicator light is functioning correctly (key off/key on). Next pull the 3 wire plug from the alternator and check the condition of the terminals (if your alternator has a separate single wire connector with a white/black wire, check it as well). If they look good check the voltage on the yellow/white wire (should be the same as battery voltage).

 

are you sure it was an internal regulator? Maybe it was external and wasnt replaced.....

 

96 Ranger would be using a voltage regulator that's within the alternator.

 

always check the 6 gauge main feed power wire between the alternator and the batttery

this is most always the problem wire that goes 1st. and check the wire connectors for corrosion

18 years is way too long to rely on that 6 gauge power wire , might as well replace the negative battery wire(s) as well

 

Good point. I believe this is a fusable link as well, so it could be "open".

Also, while these wires may look good, the copper wire within the sheilding can be green, which drastically creates resistance, dropping the voltage.

 

I have a 97 3.0 2wd with a similar problem. Black w orange (on back of alternator) Should have battery voltage if it does the fusible link is ok and so is the wire unless the insulation is coming off. On the regulator connector the Yellow wire should have battery voltage as well. It has a fuse in the distribution box - left rear engine compartment 20 amp. The black and white goes to the small connector on the side of the alternator. The Green and red wire is the exciter wire that goes to the battery light (instrument panel) which is supplied from the ignition switch and it has a fuse in the fuse panel left side of dash 7.5 amp. There is a ground wire behind the parking brake assy kick panel and supposedly one on the right behind the kick panel. Two grounds in the engine compartment - one on the negative terminal which connects to the front support. The other is a strap which is bolted to the back of the engine and goes to the wiper motor mounting bolt. Even with all this checked I still have a problem. I believe there is a resistor or diode behind the instrument cluster which is causing this problem. However I cannot deadline the truck for the time it takes to dismantle the dash for a goose chase. Any ideas?

 

As an after thought if wires are corroded cut them back to clean copper and using wire of the same gauge long enough to redo the connection. Use solderless terminals to make the connection. Put silicone grease on the bare wire before crimping on the terminal and at the connections for corrosion prevention. Battery terminals clean and tight. Use a battery terminal coat or grease to keep corrosion at bay. ALSO just because the battery says 'maintenance free' you still need to check the electrolyte level. Pry off the cap carefully and add distilled water to the proper level. Those caps capture the electrolyte and return it to the cells but some still escapes that's why this is necessary. Low electrolyte exposes the plates and that will shorten the life of the battery.
Since I'm new here I don't know the level of mechanical knowledge that prevails here so pardon me if I make the assumption most are owners and not mechanics.
(The original battery in my 97 (built 6-97) Ranger lasted until June 2006, the replacement I just replaced this week.)