Cutout Question

[Rich Largent]

Could someone direct me on how to bench test a cutout? When I bought my car the generator did not appear to be working which was not an immediate issue as I planned to install an alternator anyway. That went well and the car is fine. Now I'm looking to examining the generator and initial tests (off the car) would indicate there is some output but nothing at the output side of the cutout. I cannot not get the points to close. Any thoughts?

 

[Tom Wesenberg]

I used a reostat to vary the voltage from 3 volts to 15 volts when I made my cutout tester. The cutout should cut in between 6 and 6.5 volts, but if it cuts in between 5 and 7 volts it should still work OK. You can use a 6 volt battery charger or a 6 volt battery to check the cutout. Connect the + to the case, and the - to the input terminal. You should be able to feel and hear the click as the contacts close, If so, then you also need to check the output terminal to make sure the current is passing through the contacts. It's not too difficult to break the two small spot welds on original cutouts so you can remove the cover. Sometimes the fix is as easy as resoldering the ground wire on the pullin windings. I've found a few that let loose due to a cold solder joint. I've also had to adjust the spring to get the correct cutin voltage, and have also had to clean the contacts so the current would flow through them.

 

[Rich Largent]

Tom,
Thanks for the tip about using a battery charger. Just learned about the minimum voltage needed to engage the points right after posting my thread. Turning the generator with an electric drill I'm only getting about 4 volts, thats with the third brush adjusted for maximum output. I'll double check the brush setting and get a six volt source on the cutout to see if I can get it to engage. Good stuff, thanks.

 

[Tom Wesenberg]

The cutouts on the right and the bottom picture are original cutouts, and are better quality and heavier than the repro cutouts. Most repro cutouts work OK, even if they aren't the same quality as original cutouts.

Use an ohm meter to check for an open cutin winding. You connect to the case and input terminal (the same as the battery charger test) and an original cutout should measure about 50 ohms, while most repro's, because of fewer windings, will measure about 30 ohms.