C-195 blowing fuse

[caseybgilbert 4]

This problem started when I replaced the fuel lines on my '82 C-195. Basically, when the voltage regulator is plugged in, the ignition circuit fuse blows (regardless of the position of the ignition switch). The accessory fuse is fine. When the voltage regulator is unplugged, the fuse does not blow.

 

Because of this, I decided to replace the regulator (thought it just decided to go bad). Well, the problem still existed once the new one was installed. So, I began checking wires and found no worn-through insulation. However, the problem stopped.

 

Well, the same problem is back now. I am guessing that a wire has rubbed through the insulation somewhere and is shorting to the chassis. My last troubleshooting probably moved the damaged wire just enough to stop the short until it vibrated back into place. I am getting continuity to ground on all 3 of the wires at the voltage regulator connector when the regulator is unplugged and plugged in. From looking at the schematic, the only wires I should have continuity with ground are the 2 leads to the stator. Correct? This led me to believe that the short is between the regulator and the ammeter (however, that would cause the fuse to blow when the regulator is unplugged as well). Checked the wire from the regulator through the ignition switch to the ammeter and the insulation is good. Could the short be in one of the 2 wires going to the stator? Is it possible that there is a problem with the stator itself?

 

Any tips would be greatly appreciated. I am just trying to keep from spending several hours taking body panels off and inspecting wire again (although that may be the only way of figuring it out)

[Save Old Iron 1,571]

Sounds like you have a short circuit in the stator or the wires going to the stator.

 

"Basically, when the voltage regulator is plugged in, the ignition circuit fuse blows (regardless of the position of the ignition switch)"

 

This is likely since the the wiring diagrams indicate the 1982+ year C series do not use the ignition switch as part of the charge circuit. The B+ from the regulator goes thru the ammeter and the 25 amp main fuse directly to the battery. The ignition switch is a non-player in the troubleshooting here. 

 

 

"The accessory fuse is fine"

 

Correct, Excessive current is limited to the charge circuit - remember electricity always seeks the easiest path back to ground.

 

 

"When the voltage regulator is unplugged, the fuse does not blow."

 

OK, then then if we consider removing the RR unit as opening a switch in the charge circuit, the RR removal prevents current flowing INTO THE SHORT. So the short can be assumed to be between the RR unit and ground. The only components there are the stator and stator wiring.

[caseybgilbert 4]

Thank you. That is what I was thinking. I was wanting to try to prevent having to remove the flywheel to access the stator.

According to my service manual, voltage across the AC leads to the stator should read 28v. If less, the stator is faulty. If more, the regulator is faulty. I'm guessing that if I measure 0v then I can assume that there is indeed a shore in that circuit.

I'm sure that I will have to remove the flywheel before it is all said and done. Thanks again for your help!