Hey everybody, I bought my 48 f-5 (6 volt, positive ground still) a couple of months ago and have been working on the body since. Well, I decided to try to get the motor runnin the a couple weeks back and it was turning over until the battery died (old battery). So i put the battery charger on it and start tryin it again and it wouldn't turn over anymore. So i went and bought a new battery and tried it again and still nothin. Bought a new solenoid, still nothin. Pulled the starter, had it rebuilt (armiture, or somthin, and some other parts replaced) put it back on and still nothin. Tested the voltage on the battery, fully charged. Tested the voltage where the starter positively grounds to the motor and its getting 6.4v. I even took the starter cable off of the solenoid and tried it on BOTH posts on the battery lol, just in case, and still get nothin out of the starter (starter cable is in good shape too). I jus can't figure out what I'm doin wrong here, if this was 12v negative ground I'd be alright but I'm treading on foreign soil with this 6v positive ground stuff lol. I understand the concept and know the basics but that's about it. Any help with this is much appreciated yall.

 

6v vs 12v it really doesn't matter, all thing are equal. First question I would have is..Are you saying that the starter will not turn? If so is the starter grounded? Where do you have the ground from the battery attached?

 

How long did the engine turn over before the battery died? For instance, was it a few revolutions or did you get enough power out of the battery to repeatedly turn the engine over? And did you try it once and then again later? And does the starter kind of "thunk" against the flywheel (like it's trying to turn it) or does it just not do anything? What I am digging for is the possibility that the engine may have locked up internally for various reasons. Things that come to mind are big rats nests (you would be amazed at what has been found inside these engines), water, etc. Get yourself a breaker bar and see if you can turn the engine over by hand. 7/8" socket as I recall on the main crank pulley turning clockwise as you face the front of the truck should do the trick. Who knows? That might free it back up. Keep us posted. Welcome by the way. Where are you located. And pictures are a requirement.

 

Well the negative cable from the battery goes to the starter solenoid, and all the wires on the solenoid are hooked up correctly, well I never touched them lol. But the positive cable grounds to the motor then grounds from the motor to the firewall. And also I turned the motor over by the crank pulley and it turns fine, its jus that the starter does nothing. But when i cranked it over originally it turned for a little bit, enough time to check spark. Btw, i edited my info and added some pics doc, let me kno if I missed anythin, I'm still new to this whole forum thing lol and im located in Shepherdsville, KY.

 

That should be grounded to the frame, not the firewall.

 

That would makes sense lol, so would it be ok to jus leave it be and run a wire from the motor ground to the frame

 

But wouldn't the motor mounts themselves and the transmission crossmember serve as the frame grounds?

Thanks for the pics livinjeep. I was just kidding you about the "requirement". Looks like a pretty solid truck. I wonder if the starter repair shop didn't miss something? You've pretty much got it narrowed down to that in my opinion. I live near Whitesburg.

 

Doc, the motor mounts, like the cab mounts are all rubber insulated.

 

Yea I was thinkin the same thing doc, the repair shop came highly recommended. Is there anyway to test the starter. Also, what does it take for me to change it to negative ground. And another thing, I think I may have it confused, but the 1.5 tons are the f-5s right? Lol

 

I'm wondering if the starter drive is jammed in the flywheel ring gear, as flatheads are famous for it.
Try removing starter. Turn the engine 1/4 turn then re- install and try it.

 

Would the starter make any noise still if it was jammed cause the starter won't do anything

 

You can remove the starter and put it in a vice and ground it. Put the positive side of a 12V to it and see if it turns.
The 1.5 ton IS the F5. This looks like a 158" WB, as an F5 the model(as indicated on the glove box tag) would be 9R8T, if it's an F6 it would be 9R8TH
To change from positive to negative ground, the only thing that is effected by it would be the voltage regulator and the generator. The polarity of both can be changed,

 

If you change it from positive to negative ground, your ammeter will read backwards if you don't change the polarity on it as well (reverse the direction of the wire). But there's really no advantage to doing the switch from 6 volt positive ground to 6 volt negative ground that I can see.

Joe, where is the original grounding strap from the engine to the frame supposed to be located?

 

Use a set of jumper cables from battery ground to the starter case or near to the starter to jumper the ground wires. Did you have the store check the new starter when you bought it? You can lay the starter on the ground and use jumper cables to extend the truck wiring to the starter and engine ground to starter. This will check starter circuit and wiring. I don't know the starter mounting. Could the starter be locked into the flywheel?

You need to clean or replace the ground wires between the frame, cab, battery and the engine. Clean the positive wires terminals between the battery and the starter.

chuck

 

I have my battery grounded to a head bolt, however, the original configuration is to ground the battery to the frame rail below the battery tray and then a ground strap from there to the head bolt.