I have a 2002 mazda protege5 put new alernater on and battery tested good still not charging.

Asked by Apr 16, 2017 at 08:30 PM about the 2002 Mazda Protege5 4 Dr STD Wagon

Question type: Maintenance & Repair

7 Answers


Check for bad wires to the alternator, also look for a blow fuse related to the charging system.

Best Answer Mark helpful

I did and I could not find any bad . I also checked for voltage coming from the output post on the back of the alternator there is none. Is it possible the new alternator is bad?


Good morning Brian, it is possible the new alternator is not working, but you would want to eliminate some other possibilities. With the engine running at idle, check at the battery with your digital multi meter to see what the voltage is. At the battery it should read around 14.5-DCV. If your not getting that, check continuity of the large output wire from the alternator to the B+, a lot of times there is a fuse-able link in that line that could be burnt out.

when unhook the large wire from output post on alternator and check voltage at that post I have nothing.


You would have nothing at the alternator post. It is in the wire you should have showed battery voltage.

I think I have a computer issue the computer tells the alternator to charge. alternator tested good as well as battery. I don't think I have a short because I drove car about 6 different places in about 5 miles and still had about 12.15 volts in it when we got home. starting car each time. They don't make a repair manual for this car. all fuses are good. That i could find.


12.15 DCV is showing the battery is discharging. The battery should have a minimum of 12.5 DCV if the alternator, charging system was working. Did you check for voltage at the main wire that runs to the alternator? There should be battery voltage there. As a matter of fact you did check..." I also checked for voltage coming from the output post on the back of the alternator there is none" ...There should be battery voltage on that wire.

Your Answer:


Looking for a Used Protege5 in your area?

CarGurus has 9 nationwide Protege5 listings and the tools to find you a great deal.

Postal Code:

Mazda Protege5 Experts

  • #1
    Paul Wilson
  • #2
  • #3
    Tyler Agnew
View All

Related Models For Sale

Used Mazda Protege
18 listings
Used Honda Civic Coupe
34 Great Deals out of 1,016 listings starting at $2,400
Used Honda Civic
106 Great Deals out of 4,734 listings starting at $1,500
Used Mazda MX-5 Miata
5 Great Deals out of 179 listings starting at $8,994
Used Mazda MAZDA6
11 Great Deals out of 614 listings starting at $1,990
Used Volkswagen GTI
19 Great Deals out of 242 listings starting at $4,650
Used Ford Mustang
34 Great Deals out of 1,238 listings starting at $4,685
Used Mazda 626
1 listing
Used Ford Focus
51 Great Deals out of 2,676 listings starting at $2,000

Used Cars For Sale

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.