Battery charger low output

[abunaitwo]

Probably an easy one.
Sears 200713121 battery charger.
Was left in the weather for a while.
No output.
Took it apart. Cleaned two of the switches contacts.
Made a replacement out cord.
I now get 9v output.
Guide on how to test it???
Link to wire diagram..........
https://www.manualshelf.com/manual/...ngine-starter-model-no-200713121/page-15.html

 

[Bluejets]

Wire diagram is of little assistance.
Circuit diagram is a different thing. Chances of getting one fairly slim I would imagine.
If weather affected, look for signs of weather damage.e.g. bad connections, damage to any printed circuit board.
Meter out switches to see if working as they should.
Parts list shows both switches the same however, this appears to be an error as one should be DPDT the other DPTT.

 

[abunaitwo]

Thanks
I cleaned two of the switches.
6v/12v and 2a/12a/75a switch.
Both were corroded.
To clean the other switch, I would have to unsolder it from the board.
I also tested the diodes and the breaker.
Both seem to be good.
Sealed breaker, so can't open it up. But it does have continuity.
I'd like to test the transformer before going any further.
It does hum.

 

[Bluejets]

I doubt the tranny is defective, I'd go more to the switches and push on connectors.
Cleaning might have improved the situation but perhaps not completely.
Only a voltage test on load would determine that.
Just be aware that is mains voltage present on both switches.

EDIT: other switch on the pcb appears to be low voltage and may just be the problem.

 

[DJL33B]

If I can remember this correctly, some of the older chargers used a pulse output, and monitored the battery voltage to control the gate circuit of the SCR. You may need a partially discharged battery to test the operation of the charger.

 

[abunaitwo]

I tried it on a dead battery, and nothing.
The meter I have is a craftsman digital.
I had it in the sun all day. Got hot.
That should dry out everything on it.

 

[Bluejets]

I tried it on a dead battery, and nothing.

Really depends on what you refer to as a dead battery.
Don't know of any charger that will work on a completely dead battery or even one below recovery specs.

 

[Harald Kapp]

As the manual of the charger states:

A severely discharged battery may not
have enough charge to start the
control circuit in an AUTOMATIC
setting. In this case, charge on
MANUAL until the battery has enough
charge to accept an AUTOMATIC
setting.

 

[abunaitwo]

Battery I tried it on had 10v, so don't know if it would charge or not.
I did put in on a good battery, and it didn't do anything.
No noise, meter didn't move.
I'll fool with it a little more.