Mazda CX-7 alternator high voltage

Asked by Jul 27, 2017 at 11:56 PM about the 2008 Mazda CX-7 Grand Touring

Question type: Maintenance & Repair

I have replaced battery and alternator and is still generating high voltage
getting higher as accelerating and boiling battery . Anyone know what voltage
should be on the 2 wires between alternator and pcm .? If engine at idle and
all power consumption is on( ac high beams, windshield wipers etc seems to
be just at about 15.5v but as I accelerate it goes up to 18v or more and
already burned the low beam lights. I had alternator tested and was good,
replaced it anyway and still the same.put new battery still the same.  I saw
others with this issue but none came back after they fixed it to confirm what
was wrong.  

2 Answers

7,485

the alt is getting a wrong signal , one big wire goes to the batt. for charging , one smaller wire is the voltage signal so it knows weather to charge or not , the other small wire is the exciter for the regulator , it needs an initial charge to work , a simpler system has 2 wires and gets voltage info from the batt. and wouldn't account for voltage drops from the rest of the system , it's o.k. for a hot rod ., your experience may differ

1 people found this helpful.

I have same problem with my 2008 mazda cx7

Your Answer:

Mazda CX-7 Experts

  • #1
    Rudy_1
    Reputation
    540
  • #2
    Bern
    Reputation
    280
  • #3
    BoholMark
    Reputation
    150
View All

Related Models For Sale

Used Mazda CX-9
11 Great Deals out of 498 listings starting at $6,500
Used Honda CR-V
96 Great Deals out of 4,189 listings starting at $2,995
Used Nissan Rogue
65 Great Deals out of 4,027 listings starting at $2,919
Used Nissan Murano
27 Great Deals out of 1,321 listings starting at $3,900
Used Toyota RAV4
97 Great Deals out of 4,275 listings starting at $958
Used Mazda MAZDA3
47 Great Deals out of 2,962 listings starting at $2,950
Used Mazda MAZDA6
11 Great Deals out of 611 listings starting at $1,990
Used Hyundai Santa Fe
30 Great Deals out of 948 listings starting at $2,496
Used Ford Escape
145 Great Deals out of 6,982 listings starting at $1,785
Used Ford Edge
75 Great Deals out of 2,775 listings starting at $3,995
Used Kia Sorento
61 Great Deals out of 2,643 listings starting at $798
Used Toyota Highlander
17 Great Deals out of 1,239 listings starting at $4,910
Used Chevrolet Equinox
71 Great Deals out of 4,639 listings starting at $4,888

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.