Having trouble with an 84 f150 with the lights pulsing when the motor is running, any help would be great , This is my sons first truck at age 16, He will have his license to drive on his own in two weeks(god help us all) and need to get this fix to get the truck inpected

 

A good start would be to check all electrical connections from the battery to ground, then to other grounds, chassis, engine and sheet metal etc. After that check the voltage regulator for good connections . If that doesn't clear up the problem the voltage regulator is suspect. Last but not least , the alternator may be putting out intermittently. Unless you can full field the alternator and have the necessary meters to check, I would consider the voltage regulator itself. Its the cheapest part to start with.
You might just get lucky and find a poor connection. Go for it!

 

Thanks hanky, Thats where we will start

 

Sometimes we get so involved we forget the simple things. Make sure the alternator drive belt is adjusted properly (tight enough).

 

Thanks Hanky, we are putting on the the alt. and voltage reg. today, and yes the belt is tight but is in bad shape so we going to put on another while we are at it, Thanks again for the help