I had a starter and solenoid, self start on their own and burn both parts out. I replaced the starter, solenoid, and ignition switch. I now have the battery light coming on in dash panel, and I went and had alternator and batteries tested at O'Reillys and they all test out fine. So, is this battery light something that needs to have the computer codes reset?? Anyone else had a problem with the battery light coming on??, and if so what was the diagnosis?? Thanks in advance. This is a 2000 F250 with 7.3L diesel.

 

When you had the battery's checked did you disconnect them from each other? You could have one weak one and when there hooked together the stronger one is helping the weaker one out and it will go unnoticed until its too late. If it turns out you do have one that is bad always replace them both.

 

My battery light randomly flickered, generally after starting, and the alternator was bad.

Put a VOM on your batteries, start the truck, and then watch the battery voltage as you turn on the heater fan, headlights, push in the cigarette lighter, etc. If your voltage doesn't stay high and solid (14v+) then your alternator may be suspect.

 

John,
The batteries are new only 9 months old and I fully recharged them all thru last night.
Steve,
I am beginning to believe that the alternator could be the problem although I put a second alternator on the truck that tested as a good alternator and the dash light still came on. I am going to check the voltage with it running at both batteries to make sure the alternator is doing its job. My dash light did flicker a little, but now it stays locked in red all the time.
Thanks for the feedback it helps me to resolve this issue.

 

Over on the starter solenoid are some fusible links. Make sure they are still good and also that they are on the correct always 12v side of the solenoid. Its easy to swap them sometimes.

 

If there are any fuse links at my solenoid I do not see them. I also checked my fuse panel, and the fuses appear okay. I could have missed a fuse, so if it is at the fuse panel please let me know. Thanks in advance.

 

Mine started to do the same thing, the light would come on for a min or two then go off, i had to replace the alternator 2 weeks later

 

I may have had a misfire in the brain. It could actually be in the harness leading to the starter relay. I am having hard time remembering and i am not near my truck. But first,lets rule it out before u waste too much time looking for them. Definitely one of them is still good since it still cranks.

If you put one volt meter leadon the big terminal on the back of the alt and the other to the batt ground, is it the same voltage as the batteries (b+). If it is, forget the fusible link.

If it is, unplug the small wire on top of the alt , check the voltage on the og/lb wire. It should be the same b+ voltage.

Next, check the voltage on the LG/rd wire with the key on engine running, it should be B+.. Do not let your leads get into the engine belt.


recheck fuse 6, under hood and fuse 29 inside if any tests fail.

 

also check the plug that goes into the alternator.
if it loosens up a bit, the dash light will come on/flicker, and the batteries will not get charged.

 

I test both batteries and I get 12.50 at both batteries, and I test the wire coming off the back of the alternator and touch the black lead of tester to negative terminal on battery and get no reading nothing nada. I talked to my mechanic buddy in Austin and he said it must be a fuseable link?? I need to locate this fuseable link?? Any help is much appreciated. Thanks.

 

Alternator(s)

 

When I changed out the starter solenoid the alternator wire coming off the solenoid fell back behind other wires causing me to not see it and not hook it back up with the solenoid. I traced the wires back from the alternator and by moving and shaking the wires I was able to see that the wire was disconnected. So, my bad and a lesson learned on my part I will check more diligently next time. My batteries are now charging at 13.92, and alternator is putting out 14.02. Thanks for all the great help.

 

Glad you got it fixed and its easy to do. Props to you for gathering the information and figuring it out. Electrical glitches are some of the most difficult.