Does this sound like a bad voltage regulator? - Ford F150 Forum

Alx717 · 11-20-2009, 06:12 PM

I have a '93 F-150 5.8L. For the past couple months it has been having some starting issues, it will start sometimes, but just as frequently it won't even crank. I replaced the starter and starter solenoid to no avail, the battery passed a test, and all wires from the battery look fine. Today was one of the days that it wouldn't start, so I decided to connect jumper cables to it, and after several minutes it started right up. Later, I turned it back on and turned on the headlights, radio, and air conditioning, and with each the engine would rev up higher. I finally turned it off again and, as I suspected, it wouldn't crank at all afterwards. When I jumped it again for several minutes it started again. My thought is that this is the result of either a bad voltage regulator or alternator, but i'm hoping it's the regulator since it's cheaper. Does this sound like it could be right?

Just call me Sean · 11-20-2009, 06:38 PM

The alternator can be tested at the parts store, you don't even have to remove it. If you have a voltmeter you can check it yourself too. You can't go by looks on the cables, they could be deteriorating inside the casing. My truck has had warm hard starting issues for a while which I haven't solved completely, but the thing that helped the most was replacing all 3 cables.

Alx717 · 11-21-2009, 01:20 AM

How exactly would I go about testing it with a voltmeter?

Just call me Sean · 11-21-2009, 02:11 AM

With the truck off check the battery voltage, it should be around 12.6. Then start the truck and check it again, I've been getting about 13.8 with mine but I think it's supposed to be around 14.5.

mitchalvin · 11-21-2009, 01:53 PM

With anything above 13.8 and below about 15 is good. I believe that the 93 models have the pod mount alternator that has an internal voltage regulator on them.