Hi: I'm a newbie here, having just aquired a '49 (the title says '49, but the seller swears it's a '48) F-1. I was just wondering, is it a positive or negitive ground system. I have Crosleys & they are 6 volt positive ground, but the battery in the truck is wired as a negitive ground. You have to play with the starter button to get it to turn over correctly, and it turns very slow. It will start fine with a 12 volt jump box attached. Thanks !

 

Your truck was originally 6 V positive ground. It is quite common and pretty easy to convert them to 12V negative ground. There would be no appreciable advantage converting to 6V neg ground so if the battery is 6V it's likely wired backwards. Yes the 6V starter will spin quite quickly with 12V applied. No real harm to the starter in doing so but it could screw up other things if they haven't been converted to 12V.
The VIN# will tell you what year your truck is as well as other info. Post it here and someone will translate it for you.

 

You don't say whether you have the flat V8 or 6, but either of these are known for slow cranking even under good conditions. I wouldn't overdo the 12v cranking until you know everything is hooked up right, it won't do your points any good.

 

Is your battery 6 or 12 V? Often unknowing po's will put the wrong one in and/or hook them up backward.

Look at your coil. Which terminal is leading to the distributor? (+) or (-) Which ever of those terminals is connected to the bottom of the distributor is the way your truck is set up for ground. Your coil may also say batt/grnd which doesn't help.

Starters on 6V do turn slowly. Part of the charm..........

Starter buttons just ground to the dash to make a connection. Rust or other crud will keep them from making contact.

Also make sure all your electrical connections are tight and clean AND that you have good grounds from batt to block, block to firewall, firewall to frame, frame to block, etc, etc. 6V has to have all these. Also your battery cables have to be heavier than 12V - they should be as thick as your index finger - at least.

Oh, and as AX said, post your serial number in the top thread. We've been working to sort out the year differences for quite some time now. Some states titled trucks when they sold, regardless of the year they were assembled. If your vin starts with an 8 then it was assembled in 48. If it begins with 9 it was either 49 or 50, and maybe early 51. The serial numbers sort it all out.

 

There is another way to tell if your battery is in backwards, and that is that the amp meter will show discharge.
I myself run 6 volt stock, and have no trouble and have had several trucks with the Flathead.
I buy good batterys, and with good cranking amps. I get mine from TSC, Tractor Supply, they are Agriculture for Farm use.
Thats not the end though the 6 Volt system needs heavier cable, like 1/0 welding type thats the ones I use and solder the terminals. Make sure all are clean and tight, and that your starter is in good repair.
A worn bushing in a starter will only cause you headaches and eventually burn itself out down the road.
I have no trouble with hot starts, after driving for awhile, remember don't touch that choke, or pump a warm flathead. If you do be prepared to sit for a period.
All said and done, if you look after them they will doo the same, also don't forget their old a tired and do need attention, good luck.

 

I've looked at the ammeter while the truck is running, and it goes to charge when you put the headlights on, but the postitve battery cable is hooked to the starter soleniod. how do I correct it if it's nessassary? It's been so many years since I've polarized a voltage regulator, I don't even remember how to do it anymore. I'd like this thing to at least turn over more than a turn or two brfore you have to release and push the starter button again.
The VIN off the title is87hc69541, it's raining too hard here today to get the vin out of the glove box, if it's still there!
Thanx !

 

Racerpete84

Looks to me like your 48 was originally a 6 cyl, according to the V.I.N. I really don't know what to tell you on the wireing part without seeing it, don't really want to direct you as to what steps to take and end up burning your truck.
Let me see if I can locate a wire diagram and post it for you. Then you can take it from there.
Is your truck still a 6 cyl? If it has been changed then a 6 cyl wire diagram is no good to you, let me know.

 

Yes the truck still has the original 6 cyl flathead motor. it runs very good. I'm just trying to make it less difficult to start, as it turns over very slowly now. I've only had it a day or two, and it's been too darned rainy to check it out much
Thanx!

 

Yes the truck still has the original 6 cyl flathead motor. it runs very good. I'm just trying to make it less difficult to start, as it turns over very slowly now. I've only had it a day or two, and it's been too darned rainy to check it out much
Thanx!

 

When the truck is running the needle goes to 'charge' when the lights are pulled on? If this happens at idle then your wires are crossed at the battery. Cause it should dip down into the discharge area. You may need to reverse the cables at the battery.

Remember generators don't put out until about 1200 rpm.

Again, what post on the coil goes to the distributor body?

Polarizing: At the regulator, remove the field wire and briefly touch it to the batt terminal for a second or two. Should see a blue spark. Reconnect the field wire. You're done.

Also your vin shows it to be a 48, probably assembled around April or May. The original title state may have been one that titled according to the date sold. It wouldn't be the first on titled with a later date than mfg'd.

One last thing, how about sending some of that rain out this way. Montana's on fire.