Bad Model A Cutout?

markp213

markp213

Junior Member
The other night I was driving home and my lights began to flicker, go really bright, dim, then normal - in random order. When they would go really bright, my engine would start to stall. By the time I got home, all my lights had burned out. I took off the generator and had it tested and it passed. The generator guy said it could be the cutout.

My question is, why would the lights get bright white and burn out, and why would the engine begin to stall? How would a bad cutout be to blame? Wouldn't a loose connection explain the dimming and stalling (I assume)? I understand basic electricity, but there's room for more education! Any suggestions would be greatly appreciated.

Thank you,
Mark Passantino
Coyote, CA

1930 Model A Pickup
Completely original (restored)
Original 6volt positive ground system
 
Most likely cause is a bad ground or an open someplace between the generator and the battery.
Without the battery to regulate the generator voltage output it can go as high as 40 volts.

Bob
 
It's sounding like a bad connection.When you lose your ground the battery is taken out of the system,and the battery is what regulates your voltage.The generator will then put out up to 40 volts,giving you the bright lights.It is also putting that 40 volts to the coil,and it ain't gonna run good.Usually a lot of backfiring results.If you have a fuse in the system that could be your point of trouble.Loose holders on the fuse will come and go.There are a couple dozen places for trouble,but I don't want to dump the whole bucket on your head at once.It will be something simple,this is the first thing I would check.
 
Thanks for your suggestions and explanations, Bob and Keith.

Interesting... I forgot to mention the very loud backfiring during my adventure that night! I will double check all my connections including the fuse. Do either of you think the cutout has anything to do with the problems I described?
 
Also check your light switch to make sure no 600W has leaked out of your steering box and into the switch. This can cause the light problems. As for backfiring, I don't know. hat sounds like intermittent spark in your ignition system somewhere.
 
As mentioned a poor ground or connection in the charging circuit is most likely the cause. I doubt the cutout was the cause. Check all the connections and grounds in the charging circuit, and this includes the generator mount, which is the ground connection for the generator. Look in the charging circuit for the problem and not in the lighting circuit.
 
Check every connection in the pathway to the battery. Starting at cutout output terminal, on to junction box, on to ammeter, back to junction box, down to add on fuse, (if you have one) if not, your last connection to check is at the main battery cable where it attaches to the starter.
Quick check on main battery grounding: Lift battery lid & stick test light probe on top of + (positive) battery post, clip test light to gearshift---then with key OFF, give the starter a loooong crank. Results: light OFF= Good grounding---light ON= Bad grounding. If bad grounding, clean ground cable at the post & where the cable bolts to the frame. Somtimes you might have to add a double flat end cable from ground cable to frame bolt & attach the other end to a bolt on the trans, bell housing, or engine.
(Hope I didn't miss something. Where's Tom?)
Bill W.
 
The most neglected grounding point on a Model A is where the battery ground cable attaches to the frame. It is out of sight, out of mind, and difficult to get to. Many have not been attended to in years. You have to remove the floor board and remove the battery. There is a raised surface on the frame where the cable attaches. This area should be thoroughly cleaned of rust, corrosion, paint, and any powder coating. Wire wheel or bead blast the cable end and the nut & bolt. The battery cable connections should also be cleaned.

Tom Endy
 
If the cutout was causing problems and he had no regulation of voltage, could it have caused any damage to the condensor at the distributor?

I'm just wondering if that would cause some of the backfiring.
 
After I lost all the lights, it seemed to run fine the rest of the way home (about two miles). It only backfired when the lights would go really bright white.
 
The cutout does no regulation of the voltage.BUT,when those lights go bright,it means the battery has been taken out of the circuit,and the voltage is running away.Runaway voltage to the points/coil will give some pretty good backfires.I would be looking for a loose,not broken connection.When the lights are bright,the connection is broken,and putting high voltage to the ignition.When they go back to normal the connection is connected again,and normal voltage is feeding the ignition.That is why I bring up the fuse holder.The blades on it get weak and the connection will come and go.
 
heneste said:
If the cutout was causing problems and he had no regulation of voltage, could it have caused any damage to the condensor at the distributor?

I'm just wondering if that would cause some of the backfiring.
Click to expand...
Most likely the extra high voltage to the coil primary windings resulted in extra powerful zippo spark:eek: that could arc out somewhere or crossfire in the distributor crap, err! I meant CAP.:p Bill W.
 
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