AMI credit unit

Hello All and Merry Christmas!
I'm wondering if anyone has a photo of the correct credit unit for an AMI B, and/or a wiring diagram. The unit that was in my box does not seem to match the schematic in the A/B service manual I have. The manual shows a credit unit with 3 relays; mine contains only one relay. I'm guessing it was swapped out at some point and maybe never worked. Or perhaps the units used were modified at some point during production, and I need to do some more troubleshooting? Blows fuse whenever a coin switch is closed...
Any help is much appreciated! Thanks, Carl.

Hi Carl,
Can't re-call which CU belongs in that model--but blowing the fuse indicates only a few things--coin switch being closed for too long--wrong size fuse, or--"burned-up" coin coil--Ain't no mo in that circuit !! Ron Rich

Thanks Ron. Fuses are right sizes as per stampings on control box. I'll try bumping them up a bit. I'm not home now, but I think all 3 coils read about 6-10 ohms. They activate when I apply 24v dc externally.All 3 coin switches were bent closed when I got the box, and no rejector was present. The 25 cent coil does appear a bit burned up. It appears that in this CU the 25 cent coil must always activate, and the plungers of the other 2 merely limit the throw of the lever that turns the credit wheel (?). There is also a 100 ohm resistor that tested OK.

WRONG--NEVER, never, "bump-up" a fuse size--If anything, you want to reduce the size. The fuse only does one thing--protect the (in this instance) coil. "Bumping up", even a fraction of the correct size, leaves the coil without protection--
"Bent switch(s)" indicates that the coil has been energized longer then it should have been, and hopefully the fuse blew in time to protect the coil. "Coin switches" are designed to close with the weight of the coin, for milliseconds ONLY--never use a finger on them, and they must be adjusted so that when closed by a coin, the timing is correct. Ron Rich

Thanks Ron - somehow I knew you were going to slap my wrist on the "bumping up" idea...
I did pick up a slug rejector, so I'll put everything back together and hopefully an actual dropping Jefferson will work. Yeah, I was using my finger too!

Switch timing must be correct--too short, and it will fail to energize the coil enough to add credit--too long, and the fuse should blow.The Service Manual SHOULD show coin switch adjustment/timing info. Ron Rich