Once again I am asking for help with an electrical issue on my Williams Aztec.

On the playfield there are 10 Bonus lights that go from 5,000 to 50,000. There are 3 Bumpers - 2 in the top row and 1 below those 2 (The Bumper lights alternate/change based on a side slingshot...top 2 go on then the bottom 1 goes on). There is an Extra Ball light between the Bumpers and the Bonus lights.

When the 50,000 Bonus Light is on and the Extra Ball light is lit - the bottom Bumper light goes out and will not go on. The top 2 Bumper lights will still work. All the other lights seem to work just fine and these 3 lights work fine unless they are all on together. I have looked and can not see a connection between these 3 lights. Does anyone have an idea as to what could be causing that Bumper light to not work when the other 2 lights are on. The Bumper light works fine when all the other 9 Bonus lights are lit when the Extra Ball light is on.

I am including a picture of the bottom of the playfield showing these 3 lights. Thanks for your help.

IMG_2479 (resized).JPG

I have a little more information. I checked the Bonus unit and all the "arms" seem to be hitting the appropriate rivets at the proper time. And all of the wires seem to be connected and do not touch anything improperly.

When the 50,000 Bonus light is on and the Extra Ball light is on and the bottom Bumper light should be on:

1. When the bottom Bumper should be lit signifying 1,000 points (the Bumper does score the appropriate 1,000 points instead of 100 when the other Bumpers are lit) but the bottom Bumper light does not go on; and
2. The rest of the GI playfield lights seem to dim a little bit; and
3. The Special When Lit red light on the left side does not go on but the socket gets pretty hot; and
4. The Special When Lit red light on the right side works properly - these 2 SWL lights alternate when the flipper slingshots get hit.

Still trying to figure out how these are all connected.

When the middle Bumper is scoring 1,000 points - the 2 Bumpers above have the lamps off and those Bumpers score 100 points when the middle bumper light is on. I have looked and the socket for the Special When Lit on the left side appears to be rusted on the bottom. I will be replacing this socket when I get the new part. Could this be causing the other lights to not work?
Last night I checked the switches on the Set-Up relay and they all appear to be ok. I will check the voltage today. Thank you.

Good news and bad news.

Good news - I disconnected the faulty bulb socket on the Special When Lit light and now the Bumper light goes on when it should and the lights do not dim. Thank you for the advice.

Bad news - Somehow I did something and now the Ball Count Unit Step Up Coil on the Ball Count Unit Disc will not energize and advance the Ball number on the game (So the game is always on Ball 1). I thought it would energize by the Make & Break Switch on the Outhole relay which - I think - closes to activate the Ball Release Coil and the Ball Count Step Up Coil. Unfortunately, the Ball Release Coil does activate but the Ball Count Step Up Coil does not activate. Clearly energy is going from that switch to the Ball Release Coil as it should but it is not going to the Ball Count Step Up Coil. Does it sound like a wire is loose? Or is there some other reason this Coil is not energizing? Anyone have any thoughts?

OK. So I fiddled around with the Manual and the Schematics as best as I could - which is at beginners level at best - And I determined that the only switches that activated the Ball Count Step Up Coil were working. I then tracked it down to a Red/Yellow wire connected to the coil. Followed this wire back to the Jack Layout - #1. Took out the Jons Plug and cleaned it a little and pushed it a little and pressed it a little and put it back in. Then I followed that wire to the Player Unit Disc and I moved that Red/Yellow wire a little and pressed it a little and pushed it a little. Put the game back on and the whole thing works. Did I fix it?
I feel like the guy on the skit Who's on First: "Now You Have It" "I don't even know what I'm talking about!!!"

Thanks for your help. That wire on the Disc is kind of hard to get to but I will definitely try to resolder it. The Jones plug looked pretty good but the pin that was in question was a little loose.

So I played about 30 games on the machine today and it worked fine. Then the Ball Count started not working again. Up until 1:30 am adjusting the Jones plug and resoldering the Red/Yellow wire - that I think provides power to the Ball Count Step Up Coil - to the disc contact rivet on the Player Unit Disc. I did not have the mental strength to try the machine tonight so I will see if I did anything good tomorrow morning.

Got up this morning. Used my alligator clips to check the Ball Count Step Up coil - It was working. Put the game back together. Cleaned the contacts on all the Stepper Units. Started the game and it works great.....For now. I will assume this problem has been resolved.
Thank you for your help.

Thought I would end this by saying what I learned from this problem so maybe it will help someone else.

As a beginner electronic person I always thought that the coils had an active side and a neutral side. Meaning that I thought that one side was always connected through to the power - kind of like a ground wire on house wiring - and the other side had a switch or 2 that turned the coil on. So I thought I only had to follow one line through to the coil. Turns out I am very wrong. Both sides of the coils are active and can be on or off at any given time. In this case, one side of the coil was activated - meaning that side of the circuit was closed - through the Jones plug and then through the Player Disc Unit. The other side of the coil was activated by a certain switch on the Ball Index relay. So bottom line is I learned that when you are trying to figure out what is the problem with a coil - You need to follow both lines/sides from the coil to make sure everything is working. Probably sounds simple to pinball experts - But to me it was a real awakening.