I have noticed a slight hesitation or maybe drag of my starter on my 86 5.0 automatic. still starts fine for now but suspect not for long. getting colder may be playing a part in the situation. I suspect it could be the battery and or the starter. starter is original. what tests should I run to eliminate what is not the problem.

 

well, there is alot of tests u could do. first thing i would do, is check your battery's open voltage (connect ur voltmeter to the battery posts observing polarity w/o the cables on) which should be at 12.6 volts. if it's any lower, preform a battery load test and see if it passes that. that could be preformed at any parts store probably for free if u don't have the equipment.

if the battery checks out ok, i would move on to checking your connections. for example, take the test leads of ur voltmeter and put one on the positive battery post and the other on the positive battery cable. a good connection will read 0.00 vdc. anything higher than that will indicate a bad connection. this type of test can be preformed on almost any connection, it's referred to as a voltage drop test.

this can also be used to test your cables. only this time you should expect to see some voltage loss there. with your test leads at the ends of the cable u should see no more than .30 vdc loss.

keep in mind with these voltage drop tests tells how much voltage is being lost on each load. each number u get between all the connections and all the loads and cables should equal source voltage. voltage drop tests are more accurate than ohm testing everything b/c with some of these cables have such a large bundle of wire, it's nearly impossible for u to detect a short by this method. but because of ohm's law, if there is a bad connection, then the amount of voltage passing thru a load will be less b/c the resistance is higher.

it takes a little time and thinking, but after u work w/ it for a while, it comes pretty naturally. it sounds like u've got a bad connection or ground or it could be a switch or solenoid with worn contacts to me. these are just some things u can check b4 u have to go thru the work to remove the starter.

 

Good writeup. Clean the connections at all ends of the positive and negative cable, no down side.

 

Being that it is the original starter, the brushes inside could be worn down really short. When they wear down to the wires themselves, then, the starter dies and melts wires.

I have had good luck replacing starter brushes in many of my own vehicles including the Ford mentioned below, and on my (cough cough) GM products.

 

very easy to do. while u got the starter apart, u can do some visual inspections if u don't have some of the test equipment. great thing is it saves money over replacing the whole starter. good point holmesuser01!