I recently got my hands on a 2003 F350 6.0l with 124,000 miles on it. When I start the truck in the morning and drive the lights pulse (headlights, parking lights, and instrument lights) and you can hear the engine hum matches the electrical pulse. When I accelerate the pulse accelerates and I let off the accelerator the pulse slows. This keeps going for about 10-15 then goes away. I checked and cleaned my batteries and they are good. I'm assuming this issue has something to do with the truck warming up and once it reaches optimal operating temperature it stops. What should I look at next?

The other problem I have is that the drivers side window is scratched bad. I want to replace the seals and glass. Ive looked for instructions on this and only saw a video on removing the door panel. Does anyone have a link or pictures on the correct way on removing the glass?

Thanks for the help.

 

Today after I got home from work, and when I had enough light outside, I checked the batteries with a volt meter. They were showing 12.6 - .7 with the engine hot and running. I let the engine cool for about 3 hours and started it up and turned on all my electronics. volts read 12.5 - 12.6 on both batteries. This seems a little low to me based on my experience (1997 F-150 4.6L and vehicles with 24V systems). Is this normal?

Also I noticed that the belt tensioner has a slight rhythmic bounce to it. Later today I am going to try to remove the belt and check the pulleys.

I have been browsing alternators and all the ones labeled single (which I have ) are 110amp while almost everything that is over 110amp is labeled for dual alternators and is either for the top or bottom. Can I still put an alternator labeled 135amp dual top on mine? Or should I stick with the 110amps? My truck is stock everything even the stereo and I am on a budget so any links to a decent brand and priced alternator that would work for my truck would be great.

Any ideas would help at this point as after my long night shifts I drive a good distance on highways half asleep and the pulsing lights is getting on my nerves, and I'm sure all oncoming traffic is tired of it also.

 

I'm thinking alternator maybe voltage regulator going bad.