1990 mazda b2200 charge indicator has low voltage

batteries have no guarantee from the dealer
indicates a failed cell
have a load test done and if bad get a new battery

Go back to the alternator for the problem as it is connected directly to the battery via the cable. Alternators charge rate is 14.5 to 15.5 volts and if it is only 13.8 volts then that is battery voltage for a good battery and this means that the alternator is not charging which indicates a diode has failed and discharging the battery

Your alternator is not yet doing anything. Minimum voltage, even with all accessories on, should be around 13.5 volts. Check all fuses, connections, grounds, and wiring. Have the alternator tested if you find nothing amiss.

inspect ignition system, ensure all components are in good shape(cap rotor/coil packs, wires plugs) check fuel system and insure the pump is putting out good pressure and fuel filter is flowing good. the point of all this is mearly the process of elimination. once you know fuel and spark are good, check for a bad ground wire, check all connections, ensure a trouble code is not stored in the obd2 system (intermittant codes dont always throw a check engine light, only "hard" codes will). all of this can be done for free and will help narrow down your problem. on the note of alternator testing when voltage regulators start to fault they can come and go... you may need to let the car run for a while and continue to check it for the desired 14v. anyways shake the car down as i outlined and im willing to bet youll either find the problem or have it narrowed down, and the best part is, no out of pocket cost! ive noticed alot of guy will just recommend people to start throwing parts, or guess it could be this or could be that... this is just w waste of time and money. good luck and hope this helps!

Sorry this isnt a solution but i am having the same problem with my mazda b2200 i replaced the alternator and now the battery will not hold a charge. Please help

https://s11.postimg.org/crrcun103/generator.jpg

Click on the link.
The diagram shows generator with internal voltage regulator and with external voltage regulator, at the moment, I don't know which one you have?
The bat terminal at the generator should be hot even with the key off, is it, use a test light. If no voltage either the fusible link is faulty or the wiring circuit to battery +. You can see fusible links in diagram.
Could be other issues, the generator probably needs excite voltage or it won't work. The excite voltage comes from charge indicator circuit. Does the charge lamp on the dash work?

OK, the volt light means that the alternator is not charging the battery. It could mean the battery is shorted out, or the battery is bad or low on charge due to an alternator not charging.

Replace the Alternator and battery as indicated by standard voltage output tests under load.

The computer in the car will not operate the engine properly on low voltage.

Fixing the charging system, may resolve the rough idle (meaning that it may be trying to relearn after data was erased by low voltage of the battery), and the speed up.


Try the charging system first, and once that is repaired, reevaluate the engine driveability and speed and idle smoothness, after it relearns.

Good luck on this repair.

It indicates low or too much voltage. It's either a low battery, a voltage regulator that is going out (it's built into the alternator), or an alternator that is not charging the battery back up. If you know for a fact that the battery is good (not old and it holds a charge ok), pull the alternator and take it to a local auto parts store. Most of them will test it for free.

Did you test the Alternator on or off the truck? It might be a problem with the control system to the Alternator. The regulator need a battery feed to work, It is usually ran through an alternator fuse.

When that light comes on, it is indicating charging system problem which could mean alternator not charging for one reason or another like loose belt, faulty alternator, or yes, bad battery or connection at battery, for example. First & easiest thing to do is check all your connections to battery, which you've probably done, and make sure they're tight & clean. Make sure belt driving alternator is good & tight, and in good shape. Now boost the vehicle to get it going & test voltage at battery, after you take cables off. My guess is in your case, the voltage will begin to go down, indicating a bad alternator, that will need to be replaced.