yeah a Ford question...forgive me

I posted this in the Ford forum, but they aint no help. Nobody has even looked at it yet hardley..I figured nobody would mine giving me some advice in here. Sorry to disgrace the forum like that.

Ive got a 77 F-150 4x4 with a 6.6(400) and a C-6.

My first question is, the last few days I've been upgrading things inside the truck. I swapped a gague cluster from a 79 F-350 into mine b/c mine was falling apart. The factory one had the dummy lights for the ALT and OIL pressure. THe new set of gagues has oil pressure and charging gagues instead of the lights. Is their any way to get the gagues to work that took the place of the dummy lights?

Now here's the main question. After I swapped the dash, the truck is running off of the battery. It seems as though the alternator is not even charging at all. I've tested both the battery and alt, so I know its the alternator or something between the alt and battery. The dash wouldn't have anything to do with this would it? It seems like it just started this after I did the swap. The only thing on the dash I have hooked up is the fuel and temp gauges and the dash lights for night.

I posted this in the Ford forum, but they aint no help. Nobody has even looked at it yet hardley..I figured nobody would mine giving me some advice in here. Sorry to disgrace the forum like that.

Ive got a 77 F-150 4x4 with a 6.6(400) and a C-6.

My first question is, the last few days I've been upgrading things inside the truck. I swapped a gague cluster from a 79 F-350 into mine b/c mine was falling apart. The factory one had the dummy lights for the ALT and OIL pressure. THe new set of gagues has oil pressure and charging gagues instead of the lights. Is their any way to get the gagues to work that took the place of the dummy lights?

Now here's the main question. After I swapped the dash, the truck is running off of the battery. It seems as though the alternator is not even charging at all. I've tested both the battery and alt, so I know its the alternator or something between the alt and battery. The dash wouldn't have anything to do with this would it? It seems like it just started this after I did the swap. The only thing on the dash I have hooked up is the fuel and temp gauges and the dash lights for night.

Jev, Been years since i've ben messing with the old ford but the oil sending unit on the block should be easy to change to one for a pressure guage, i dont know about the alt guage except that now with your system not working i would suspect a wiring difference or perhaps the fact of the dummy type alt light may be whats causing your charge system prob, and changing to a charge level guage sending unit may fix one or both of your probs. seems like i remember that when you have dummy lights it was just one wire going to sending units but on level guages there may be two as if its in a loop and your ignition switch is not set up for that?.. NOT SURE IF IM HELPING BUT YOU WOULD NEED TO LOOK IN OLDER LARGE CHILTON SHOP MANUALS TO FIND PICTURES THATR MAY HELP...jj

I have the complete haynes manual for the truck, and it shows like 15billion schematics, but none of them seem to make sense. They're not labeled very well. The charging system secton of it however shows a very simple schematic consisting of the ALT, Voltage Regulator, Starter Solenoid, and Battery.

look at the schematics on the older vehicles if the dummy light burned out the alternator would stop charging. if you have an alternator shop (even a good parts store)around they can tell you how to bypass it to get it to charge.

JEverette Check your IM.

I think I've gotten it narrowed down to the voltage regulator. One of my dads friends who's a certified mechanic said the dash in no way would make that happen...and I replaced the alternator yesterday SOOOOooo...its got to be the regulator. Go figure..it was the cheap part.

And I narrowed it down WRONG!! This thing is pissing me off now. I know the current does not go through the dash now, but theres only like 4 wires in the whole damn charging system. It's about to drive me crazy. I took my Haynes yeesterday and traced each wire just to check for breaks and NoThInG!! I guess its a possibility that the new alternator could be bad..that would be just my luck. Any more suggestions?

My ford has had the smae issues. I have owned a 1977 F150 with a 400 for about 13 years now. You can change the Oil pressure sending unit that is made for a gauge, as well as the temp sending unit (located near water pump on block). The volt gauge never has really worked for me and hundreds of others. There is a lengthy process to modify the gauge to read true alternator output, I use http://www.ford-trucks.com/forums/forumdisplay.php?f=38 for my ford info. There a lot of people in the 73-79 forums.

good luck and let me know if I can help as I have been all through this truck plenty of times.

Good Luck

an, what do you think the culprit is? I've replaced the alternator and voltage regulator with no success. CHecked all the fusible links, traced all wires cleaned all connections...etc.. I've hit a brick wall. I'm not as worried about the gauges working as the truck charging....GRR!!:banghead::angryfire:swear:

check the plug(s) on the alternator they used to go bad,check your fuses, if all else fails put your old dash cluster back in and if it starts charging you will know it has to do with idiot light vs gauge I have seen it before when the bulb goes out they quit charging.

If everything was working before the swap (dash) and you did a continuity test on the fusable links then I would agree with fleetech. I too owned a 77 400 w/C6, best damn truck I ever owned! I too had an alternator problem once, even after replacing the alternator, it still had a problem, then all of a sudden it worked! I would get your alternator, regulator checked to be sure, oh, and make sure that the regulator has a good ground.

I took the new alternator back to Orileys and let them check it again and it was puttint out 15 volts. I've put a new voltage regulator in it, checked all plugs and connections and grounds. I guess it's nothing more than the dash now. I can't re-use the old one b/c it crumbled to pieces when I removed it. Thats why I took it out...it was falling apart. Guess I'll have to hit up a salvage yard.

I took the new alternator back to Orileys and let them check it again and it was puttint out 15 volts. I've put a new voltage regulator in it, checked all plugs and connections and grounds. I guess it's nothing more than the dash now. I can't re-use the old one b/c it crumbled to pieces when I removed it. Thats why I took it out...it was falling apart. Guess I'll have to hit up a salvage yard.

I may not be helping jev but what ignition switch are you useing? the old or the 350 switch? I cannot completely remember but i had this gorrila problem years ago and wha t i came to find out was that the charging circuit does go through the ignition switch and while swapping out interior parts and engines while building a hot rod i could not get a charge and it turned out to be the ignityion switch i was using did not match with the other parts i swapped.... you mentioned you had a haynes with wireing diagrames but what you need is the old school large thick chiltons or better an original ford truck shop manual. This crap that you can buy at autozone is just toilet paper as far as im concerned. and its hardly readable as you mentioned...you need to go find the very old mechanic in town who may still have these books. I have some of them but i cant help you here in WV. I know someone has already told you in could not be the cluster or anything inseide but what about that ignition switch?...jj

I took the new alternator back to Orileys and let them check it again and it was puttint out 15 volts. I've put a new voltage regulator in it, checked all plugs and connections and grounds. I guess it's nothing more than the dash now. I can't re-use the old one b/c it crumbled to pieces when I removed it. Thats why I took it out...it was falling apart. Guess I'll have to hit up a salvage yard.
What i meant to say was that the voltage regulator takes its que from the ignition switch after you turn the key the engine turns and if it start your system will sense it through the ignition switch and it open the charging circuit.. youll have to find someone with a better memory on this ..im responding because i remeber the frustrating four days it took me to locate the problem and i had to go to a very well experienced mechanic friend who knew the problem as soon as i said it...jj

Well, I'm using the factory switch..or the one that was in it when I bought it, you can tell it's been changed before. The 350 still has the switch in it, so I could go get it if I needed it. I've noticed that the ignition switch does tie in with the stuff somehow, but I sure don't know where or how.

I GOT IT!!!!! I finally figured it out yesterday afternoon. I danced around the yard many times. Wiring can be such a pain in the ass sometimes.

Heres a pic of the beat I've been working on.

http://i14.photobucket.com/albums/a342/jceverett/DCP_1497.jpg

I GOT IT!!!!! I finally figured it out yesterday afternoon. I danced around the yard many times. Wiring can be such a pain in the ass sometimes.
so what was it. I like the the beeter somthing to scratch while the silvy,s in the driveway...jj

I figured out there are 2 wires coming from the ignition, and 1 resistor wire. I was only using 2 of them..a hot and the resistor when the gauge worked, only showing Discharge. I traced my schematics again and hooked up both positives coming from the ign. and then the resistor wire to the other only remaining wire.

I figured out only having 2 of them hooked up was failing to charge the field wire on the ALT, causing the alternator to put out nothing.

Yeah, that's what I thought it would be.

I bet it is