I recently got a job doing insulation in attics, working with another kid who is 25. He is trying to get his life back on track after having his daughter and doesn't have a vehicle. We have been using my '74 F-250 Super-Cab everyday with no problems. And although I am making very good money, (I made $125 for a 4 and a half hour job) I will not get paid for another week or two. We have worked 12-13 hour days Wednesday - Friday. I leave my house at 6AM and don't get home until 9PM. Wednesday we had the 4 and a half hour job I mentioned above and the guy was very cool, he used to build FE engines for racing and had a good shop. He looked my truck over really well and said it has a mild cam in it and runs excellent. So I stayed and we were talking for a couple hours after the job was done. By now it was nighttime and we go to turn on the headlights on and nothing. So after checking fuses I remembered the Hi Beams. I flipped the switch on the floor and we left. I was relieved because I was contemplating leaving the truck there (35 minutes from home) and coming and picking it up in the daytime. So we drove all the way home with the Hi Beams on with no issues. We did the same thing Thursday night. (With working 13 hour or so days I didn't have the time to check into it.) I think it was the dimmer switch on the floor. So Friday my co workers cousin came out to help us finish this really tough job and make sure we had all the tools we needed. The truck would not start at all without jumping it, but once it was on the jumper cables it fired right up. So we just jumped it all day. So by nightfall we were very tired after working another 12-13 hour day and were on our way home when all of a sudden we notice our headlights are getting dimmer, and dimmer, and then we have no dashlights at all, which also means we have no taillights. We could not drive home without lights. So we had no choice to leave the truck overnight. So his cousin gave me a ride home and picked me up Saturday morning so I could go get my truck and work on it and figure out what the issue was. So I made it home without incident, other than when I got home the truck was on E, and I was afraid it was going to run out. And then when I started it back up again, it was on a a quarter of a tank. So I knew I had to fix the problem with my truck. So first thing I did was had my brand new battery re-charged up because we'd been running off it for the past 3 days and for some reason my alternator, which was only 2 years old was not charging my new battery. This is one of the biggest batteries they make, it puts out 850 Cold Cranking Amps. My friend told me that it was my Voltage Regulator, so I pulled my old one off, which looked very vintage and was a Weiss, Made in the USA. (So you know it's old) I then went down to my local O Reilly's, and bought a $25 Voltage Regulator. I installed it and I thought all would be well. My friend told me a good trick to check to see if everything is working is start my truck, and pull off the + battery cable (Which is also new) and the truck should still run, as it should run off the alternator. When I did that, my truck dies. So I took the truck down to the O Reilly's so they could test it because they can test your voltage regulator and alternator. They told me two different times my Voltage Regulator was bad, and that my Alternator was good, and my battery and starter was good. (Which are all new) So I took the Voltage Regulator back off and cleaned and checked all my grounds and put it back on and it still tested bad. So at this point I was livid, so I returned that cheap piece of junk and bought the most expensive one they had, with a lifetime warranty. Which was $45. I figured my cheap one was probably defective, that there was no way I could get two in a row that are defective. So the new one still tested bad. So I asked them what my alternator (which was only two years old, I have the receipt for it) was putting out. They told me it was putting out 12.5 my friend told me my alternator needs to be putting out at least 13 or 14. And if it isn't putting out at least 13 it is bad. So I went and bought a new MoterCraft alternator with a lifetime warranty, cleaned all my grounds, checked all my wires, and installed it. They checked everything again and told me it was putting out the same voltage as my old alternator was, 12.5 and that my new expensive Voltage Regulator was still testing bad. So I spent another $50 to replace my alternator that wasn't even bad. I also bought a $15 dimmer switch, replaced that, and now my regular headlights work. My old dimmer switch was probably original. So I went home and did my home test again, and the truck will still not run off the alternator, I though maybe there is a fuse for the Voltage Regulator, but there isn't. I spent over $100 (which was all my reserve money for situations like this) only to now not have a penny to my name and the problem is not fixed. No one can explain why the truck will not run off the alternator except that it might be a fusible link, which I will check once my neighbor gets home from work so I can borrow his test light. The truck is getting harder to start and I do not have my charger anymore, it seems to have disappeared (I was just going to charge my battery every night and not worry about it) The good news is so far I don't have any work today. But I might have work tomorrow in San Diego, this is stressing me out and no one has any explanations. I really hope you guys can help me figure this out, it is causing me to lose sleep every night (which is bad when you work as much as I am right now) and I worry that I might get stranded on a job site somewhere.

 

Have you had the starter checked out? Its possible it may be grounding out internally and I do believe the charging system is connected to the starter...Ive had the hot wire burn on a header before and Ive lost ALL electrical power. also check the starting solenoid...

 

Can you summarize what the problem is in 3 or 4 sentences?

 

Holy 'War and Peace,' Batman!!
Allow me a synopsis?
Battery = good, accepts and holds a charge. When tested (at the battery?), alternator not putting out 13-15 VDC, correct? Regulator (new$ & newer$$?) tested "junk" at the parts store...or at home?
So...your vehicle is running (starts up and runs) only off the battery; new alternator and new regulator(s) tested to be t*ts on a bull hog, and no fried wires are visible, correct?

An after thought here - you said your headlights (low beams) weren't working - slowly died, but the high beams were - maybe the low beam circuitry is going south? Just a thought....
Help, Mr Wizard...aka fmc400!!!!

 

Sorry about the long post, I was trying to give you guys a background.
I replaced my dimmer, regular lights work now.
My battery charger is too small to charge this huge battery.

 

Is that the summary, or have you figured it out? What is the actual problem (such that we don't have to spend 20 minutes reading)?

 

No one knows what the problem is.

 

Have you checked to see if you are getting power to the regulator from the ignition switch?

 

Okay, let me be more clear. I'm asking YOU to describe, in a very clear statement, what your question is. In other words: what is your truck doing that goes against your expectations of what it SHOULD be doing?

Maybe I'm just slow (since others are chiming in with advice), but your first post took up over half of my 24-inch wide monitor, and when I asked you to summarize it, all you told me was that you replaced something. If I'm really just the only one not following, then I'll stop complaining. A this point, it would have been quicker for me to read your novel.

In other words, I still have no idea what you're saying.

 

Giving pertinent background is helpful, but information about your working hours and money earned and whatever - stuff that has nothing to do with the problem - just wastes peoples' time.

You should also use white space to break stuff into paragraphs; giant walls of text are hard to read and many people won't spend the time on it.

 

Long post, but to sum it up, he replaced the alt and reg, only to still have 12.5V @ the battery when running.

I suspect a wiring issue, either at the starter solenoid (fuse link/bad connection) or in the voltage regulator plug/wires.

 

Grubbworm has some diagnostic procedures in his Albums:

Ford Truck Enthusiasts Forums - Grubbworm's Album: Troubleshooting help, for anyone that needs it.

Ford Truck Enthusiasts Forums - Grubbworm's Album: Troubleshooting help, for anyone that needs it.



The trick of disconnecting the battery with the engine running is not a recommended diagnostic procedure (Google it).

Get yourself a volt/ohm meter and some diagnostic procedures (Grubbworm's for example, maybe others can also help you with those) and do some valid testing. Yes, you very well could have a wiring problem.



FWIW I had a local auto parts store "test" my battery and charging system, it was some kid with a hand-held meter. There is no way he can do a load test with one of those, but I digress. Kid told me everything was fine and told me I had a wiring problem that was draining the battery overnight.

The real problem was at least one and possibly two dead cells in the battery, something a load tester can help detect.

But if your problem is having only 12.5V measured at the battery with the engine running, the battery is not your problem.

 

i had this problem volt regulator is not charging the field on the alternator run a hot wire from battery to field post you should get 14 volts. it could be as simple as the field and battery wires are backwards on the alternator.I havent seen a replacement aftermarket volt regulator that works try a junkyard for oem parts.