As I'm slowly working toward getting my 48 F3 road-worthy I continue to encounter issues that need to be addressed. The latest is what seems to be a charging issue...before I start replacing parts I'd appreciate any advice on where to start. I've got the truck up on jack stands fixing the brakes at the moment and I usually go out and start it everyday. I've noticed that after it runs for a while and I shut it off it doesn't want to restart. The starter really drags like the battery is dead...and I keep a trickle charger on the battery all the time...original six volt system. Thoughts?? Thanks. Jeff K.

 

Does your ammeter work? If so, check to see that the needle is somewhere to the right of the center mark when the engine is running. You should also see if the needle increases it's rightward movement as RPM increases. These old ammeters are not accurate, but do indicate whether your charging at all or not. With the key in the "ON" position and engine not running, it should show a discharge.

Absent a working ammeter, whip out any old voltmeter and place the leads on the terminals of the battery. A fully charged 6V will read somewhere around 6.8 or 7 volts. As these batteries become discharged, the voltage also drops.

If your voltage is OK, make sure all your connections between the battery and starter are clean and tight, and that the wiring is in good condition. When I began getting my F-2 back on the raod, I replaced the battery cables as a matter of course. They didn't look bad, but I didn't want any issues down the road.

If all the above checks OK, then go to your starter. You can do an amperage draw with any decent hand held digital voltmeter, just follow the instructions for your particular meter. When cranking, the amperage draw should be a maximum of no more than 190 amps (make sure your meter can read that high, or you could let the smoke out of it). High draw indicates that you have some issue with your starter, most likely it is "dragging". A dragging starter , especially on these old critters, is usually due to a mechanical problem, the main one being that the bushings and bearing have become so worn as to allow the armature to rub against the pole shoes inside the case. A classic symptom of a dragging, and the first indication that such wear exists, is that the starter will crank just fine when the engine is cold, but once warmed up, the clearances inside it decrease (warm things expand), till there is the dragging, and slow cranking. A quick removal and inspection of the starter will verify the condition: Scratches on the pole shoes and armature, sloppy bearings, etc.

These are extremely simple systems, so a methodical approach should very quickly unearth the problem. I hope this has helped.

 

Thanks J.D., what you've described with regards to the starter sounds exactly like the issue I'm experiencing...cold no problem...warm serious dragging. I'll check out the systems you recommended...appreciate the advice. Jeff.

 

How big are your battery cables and how good are your connections? 6V needs some serious amperage to work. 4 gauge battery cables intended for 12V won't cut it. I use 1/0 on my cars and they spin the starter fast hot or cold.

 

Just a thought.....if you are running the all original charging system with a generator. Generators tend to not produce a lot of current at low RPMs. It could be that the first start of the day is with a fully charged battery since you are using the trickle charger. Starting takes a lot of current, and the ignition system will draw a couple of amps while you are running it (more at low RPMs). If all you did was idle it for a while, it is possible that the generator isn't coming on line.

If you have a voltmeter, put it on the battery and look at what is happening through each phase of your morning run. Check voltage prior to starting, check during cranking, and see what it is sitting at while it is running. If the generator is working, the voltage should be higher while it is running than it was sitting there. If the voltage doesn't come up, rev it up a little to see if the generator comes to life at around 1600 to 2000 RPM. If the generator and regulator are working properly, the voltage should be around 7.0 to 7.3 while running.

If the voltage drops way off during cranking, it is possible that you have a weak battery.....you'd need a load tester to check that. They have those at most auto parts stores to test batteries for customers. Most of the kids won't have seen a 6v battery!!

 

Old Dan,

Thanks...some good tips...I will try this tomorrow when I get home...I'll post what I find out later. Jeff K