Question about 1988 Ford Mustang

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Speed sensor low voltage

Hi i ave 88 mustang manuel tranny problem is my speedometer is flucuating and cruise control is making up its own mind and about the sametime my voltage on the panel was dropping slowly for about a week.. my amp light goes on when i start the car and goes off when i boost the rpm and goes back on when is on idle.. Is the speed sensor able to mess around with the voltage gauge..... no problem starting.multimeter red 12 volts on battery and 12 when startedand running..u think if i change the sensor it will change the voltage on my gauge......help would be great

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  • Angelo Attard
    Angelo Attard May 11, 2010

    check the voltage at the battery first with the car running at 2000 rpm it should be 13 to14.5 volts



    if the voltage is to high or too low replace alternator



    check this and get back to me

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Lets do this ck voltage with voltmeter at battery post on the back of you alternator. you have to have at least 12.35 volt at least. most likely around 14.-16.. but 12.35 min. any lower replace.

hope2help

Posted on Apr 17, 2009

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----------------------------------------------------------------------------------
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