I have a 1981 Mercury Grand Marquis and it keeps loosing power after 20 minutes of riding. I have anew battery and alternator. I unhooked the radio, AC compressor, and fog lights. It still dies.

Asked by Oct 15, 2016 at 10:07 PM about the 1983 Mercury Grand Marquis

Question type: Maintenance & Repair

I have a 1981 Merc Grand. The previous owner put a 5.0/302 motor in it. There
are a few things that has been converted on the car such as the fuel filter now
requires a 1976 filter. The factory recommended alternator is no longer the one
that works for the car. What could the problem be?

3 Answers

1,535

It could be some wiring going to the alternator. Maybe it isn't getting activation power because of differences in wiring. Measure the voltage while running, if less than 14.5 volts, it's not working. One needs the circuit diagram for the car, and for the car with the alternator you're using, and a genius to figure it out.

75,535

Most likely the 1976 alternator can't keep up with the demands of the 1981 electrical system. An '81 Grand Marquis uses a 65, 70, 90, or 100 amp alternator. While a '76 Grand Marquis uses a 38, 45, 55, 61, 90, or100 amp alternator. There are 2 choices for the 90/100 amp alternator for the '76. One has a 9 o'clock terminal position and the other has a 12 o'clock terminal position. I'd suggest getting the 100 amp alternator. HTH. -Jim

same problem with my 81 merc. i replaced the voltige regulater and got the higher priced one. problem fixed

Your Answer

Grand Marquis

Looking for a Used Grand Marquis in your area?

CarGurus has 1,521 nationwide Grand Marquis listings starting at $995.

ZIP:

Mercury Grand Marquis Experts

  • #1
    Tracy Hooks
    Reputation
    5,910
  • #2
    kbro
    Reputation
    2,210
  • #3
    Js08016
    Reputation
    1,980
View All

Related Models For Sale

Used Lincoln Town Car
13 Great Deals out of 1,587 listings starting at $1,200
Used Ford Crown Victoria
3 Great Deals out of 877 listings starting at $2,000
Used Chevrolet Impala
506 Great Deals out of 32,380 listings starting at $1,000
Used Ford F-150
3,046 Great Deals out of 230,455 listings starting at $1,300
Used Dodge Charger
326 Great Deals out of 35,855 listings starting at $1,999
Used Ford Mustang
341 Great Deals out of 42,379 listings starting at $1,488
Used Honda Accord
818 Great Deals out of 88,085 listings starting at $1,444
Used Chevrolet Caprice
136 listings starting at $6,995
Used Chevrolet Camaro
398 Great Deals out of 31,484 listings starting at $3,495

Used Cars For Sale

2011 Mercury Grand Marquis For Sale
21 listings starting at $4,495
2010 Mercury Grand Marquis For Sale
7 Great Deals out of 78 listings starting at $2,290
2009 Mercury Grand Marquis For Sale
80 listings starting at $3,200
2008 Mercury Grand Marquis For Sale
3 Great Deals out of 132 listings starting at $2,990
2007 Mercury Grand Marquis For Sale
116 listings starting at $1,600

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.