I have an older roll around Sears Automotive Battery Charger Engine Starter 6/12volt, 40amp with 225amp start feature. It is model 934718460 The settings are 6volt slow setting, 6volt fast setting which shares its position with 12 volt slow, then there is a 12 volt mediuim, and a 12 volt engine start. And, of course a timer, and the ammeter.
This one was made by Hitachi as best I can tell, for branding as a Craftsman/Sears.
If you hook up the leads to a battery, the ammeter on the machine registers absolutely nothing. I figured I'd check to see if the ammeter had just given up the ghost.
So, I hooked up my trusty Extech 430 multimeter to the leads to see that there is absolutely no 6volt or 12 volt DC(actually extremely tiny and inconsistent bouncing .0000 mv readings). However, accidently hitting the range button produced a strange discovery.
*6 volt low reads- 7 volts AC output
*6 Volt start-12 volt low(this is a combination setting) low puts out 12.9 volts AC output
*12 volt medium reads 14volt AC output
*12 volt start reads 17-18.x AC Output
What would cause a battery charger that takes in 120v AC and transforms it to 6 and 12 volt DC, to put out AC at the battery charger leads ?
What kind of numbers should I be seeing at the rectifier on this machine- ie voltage and AC or DC ?
Can anyone offer me any diagnostic procedures to execute from here ?
Finally, if it turns out to be the rectifier, the OEM rectifier is long discontinued. I am not afraid of soldering and reconnoitering- is there a chance I could source a substitute from digikey or the like ?
Thank you all.
This one was made by Hitachi as best I can tell, for branding as a Craftsman/Sears.
If you hook up the leads to a battery, the ammeter on the machine registers absolutely nothing. I figured I'd check to see if the ammeter had just given up the ghost.
So, I hooked up my trusty Extech 430 multimeter to the leads to see that there is absolutely no 6volt or 12 volt DC(actually extremely tiny and inconsistent bouncing .0000 mv readings). However, accidently hitting the range button produced a strange discovery.
*6 volt low reads- 7 volts AC output
*6 Volt start-12 volt low(this is a combination setting) low puts out 12.9 volts AC output
*12 volt medium reads 14volt AC output
*12 volt start reads 17-18.x AC Output
What would cause a battery charger that takes in 120v AC and transforms it to 6 and 12 volt DC, to put out AC at the battery charger leads ?
What kind of numbers should I be seeing at the rectifier on this machine- ie voltage and AC or DC ?
Can anyone offer me any diagnostic procedures to execute from here ?
Finally, if it turns out to be the rectifier, the OEM rectifier is long discontinued. I am not afraid of soldering and reconnoitering- is there a chance I could source a substitute from digikey or the like ?
Thank you all.