charger 2 open diodes yet still charging @~5A?

[svgoodkarma]

I have an old style Lester-matic charger (with manual timer) for a '60's Cushman Golfster. When charging, the ammeter on the charger never reads above 7 amps. It will eventually go down to around 5 amps (just in the green). I do manage to charge the cart this way, it just takes a lot of charging (basically all night and all day).
So, I tested the continuity of the diodes, and they both tested open (no continuity). I was expecting one to be failed either open or closed, but not both, since it is still charging.
The charger's got the old style aluminum heatsink with the press in diodes, and it's bolted directly to the top of the transformer. (see pics)
I'm about to order a new heatsink w/ the diodes but I want to ask here first.
The question is; does it make sense for it to still be charging with both diodes failed open (both fuses are still ok)? I don't see how the charger is producing DC without diodes, or am I missing something?
Thanks!

[svgoodkarma]

I just want to say a big thank you to George at Lester Electrical for taking the time to help me over the phone. What great service for a very old product. I think most companies would not have given me the time of day, yet George (who remembered working on these old chargers back in the 60's!) walked me through a few tests to determine that the transformer and capacitor are good, basically narrowing it down to the diodes. He did confirm that if both diodes are failed and open, there should be no charging. So all he could suggest was maybe my cheap meter was at fault. Who knows? I guess I'll order some new diodes.

[69makinitmine]

Were you using the "regular" ohm function or the "Diode check" function on the meter? If using the ohm, there might not have been enough voltage from the meter to pass through the diode. The Diode check function (the one with the little diode symbol) actually puts .5 vdc through it to "trip" the semiconductor bridge to allow it to conduct! When reading the meter on the "diode check", you will get .500vdc one way and 0vdc the other (reversed)!!! Try it on the old rectifier board and let me know if your readings were correct this time. I'd bet just one is bad so your putting out half wave, or half DC and that's why it takes so long to charge. Feedback is GOOD! I've got 3 Lester automatic chargers I need to find time to dig into, 24v, 36v, and a 48v...