is this normal?

[kngkong]

Hey all,

Just going through the electrics last night and came across something that has me a little confused. So far I have only wired the main parts of the bike: battery ignition switch, coil to breaker, and generator. I am getting a good spark to the plugs and the engine is firing, i dont have the tanks hooked up so havent really run it yet as Im waiting for some carb parts. But, since then I had done a little more wiring in the dash to get the gen and oil lights to work, which they do. Last night I was checking continuity on either side of the points, one tester on the arm, other on the other side points and Im getting continuity even with the points open. With the dash bulbs out I dont get continuity. Reading through the site it sounds a lot like this thread Circuit breaker short found but doesnt seem like he ever get all solved.

Is this normal?

I'll forego trying to start it until it gets worked out and while Im at it. Whats a good fuse amperage to start with? 20amps?

Thanks for all the help.

[kngkong]

still not having any luck figuring this out. maybe this will help. This is how im wiring the dash lights. Note, they're not bolted down at the moment because i was in the middle of moving wires around, but this is essentially how i am connecting the dash light. One wire to the top terminal, one to the lower. Is that correct? I cant figure out another way to make it work. I think this is where my problem is coming from.

[kngkong]

after reading this post in the knowledge base a couple more times Circuit breaker short found
I'm kinda coming to the conclusion that I should be reading continuity between the points when the bulbs are installed.

Can anyone else confirm this?

[FlatHeadSix]

Kong,
The timer (circuit breaker) goes to ground when the points close. The stationary side of the points should always be grounded to chassis ground (zero ohms), the moveable arm of the points should be connected to the negative side of the coil. When you hook your meter up for a continuity check you should disconnect the wire from the timer to the coil and check it that way (isolate the components and test them separately).

The upper terminal in the photo you posted is the #8 terminal, it gets full battery voltage when the switch is turned on. The lower terminal should only have one wire connected to it which goes to the oil pressure switch on the cam cover. When the engine is not running (no oil pressure) the oil pressure switch also goes to ground and turns on the light. You really should disconnect all the various components and test them independent of each other to get true indications of any problems in the circuit.

The #8 terminal is also wired under the dash plate to the generator light so it will go to ground through the light when the engine is not running because the relay is open. Remember that Harley "GEN" lights are not wired like automotive "AMP" lights, the contacts in the relay which feed the "GEN" light are grounded until the relay closes. When the generator starts making electricity and closes the relay it opens the relay contacts which provide the ground for the "GEN" light and it goes off.

Both of the dash light sockets should be isolated from the base, check this first. If either one of the dash light bases are grounded to the base plate you need to fix that first.

If you are trying to wire it the way it came from the factory you need a diagram for the way they were wired prior to 1947. I tried to scan the diagram you need but it came out too fuzzy, I'll try it again tomorrow. Just remember that all the stuff from 1947 and up is different so don't try to use the panhead era diagrams, use the knucklehead diagrams.

I'm confused, are you? Don't worry, we'll get it sorted out.

mike

[kngkong]

Thanks a lot Mike, this is very helpful. Just a couple questions

Kong,
The timer (circuit breaker) goes to ground when the points close. The stationary side of the points should always be grounded to chassis ground (zero ohms), the moveable arm of the points should be connected to the negative side of the coil. When you hook your meter up for a continuity check you should disconnect the wire from the timer to the coil and check it that way (isolate the components and test them separately).
mike

i have tested for continuity with the wire to the coil removed and there is none. so this leads me to believe there must be something in the dash lights thats messing this up. As you can see in the photo I dont have the standard bulb set up. I would like to correct it with the proper sockets at some point, but for the time being can you suggest the best way to wire those sockets I have? Seems that in the standard dash setup the oil light is getting power from #8 terminal, so I can wire one side of the bulb to that? Where should the other wire go? If i put it to the lower terminal then this will cause continuity at the points but where can I put it so it wont?

Either way, I decided to forego getting the bulbs to work correctly until I understand that better. I was able to borrow some float bowl parts from a friend and got her running tonight. It sounds great, just like I hoped it would. Will try to post a video soon.

Im gonna read your post a couple more times and maybe Ill start to understand what I need to do.

thanks a lot!
john

[kngkong]

video

[FlatHeadSix]

cool video John, you must have something hooked up correctly if it runs.

As I mentioned above, the dash lights must be insulated from the dash plate or nothing will work right. The metal bulb sockets should be connected ONLY to the terminal posts directly below them, the lights will recieve their ground connection from either the relay or the oil pressure switch connected to those terminals. The "hot" side of both lights comes from terminal post #8 directly above the oil light which is also the main power supply for the ignition coil and the hot side of the horn. In your photo the green cloth wire probably goes to the plus side of the ignition coil, the black cloth wire is probably the horn feed. If you are connecting your external power to the 2 terminals above and below the oil light you will lose your chassis ground as soon as the engine starts because the oil pressure switch will open and disconnect it from the chassis. Connect your black ground wire directly to the frame somewhere, there should be a lug on the upper right side behind the seat post for that purpose.

here is the wiring diagram you need, you should be able to copy it from here and blow it up so it is more readable.

mike

[panhead]

Here's a bigger picture:

[kngkong]

Hi Mike and Panhead, thanks for the diagrams. Yeah, thats pretty much the same one Ive been using. I think ive done everything right as far as that goes. I think my problem is coming from the fact that at some point someone replaced the original bulb socket with those rubber ones with two wires you can see in the picture. They are completely insulated from the dash base so that is not interfering. Since its not the stock setup if I attach one socket wire to terminal 8 where should the other end go? if i wire it the way shown in my pic the lights do work, but then i get continuity at the points. Terminals are not contacting base plate in any way and I do have my battery grounded to the frame.

im pretty sure im getting continuity from current traveling from points to coil, coil via green wire to terminal 8, through the bulb, and then down the black wire to the oil switch or gen switch completing the circuit. and this is where Im confused. how do i wire the bulb for this not to happen as it seems like the only way it could work?

i havent tried running it with the bulbs in as Im a little worried that might mess something up.

I need to double check but last night i noticed that the ignition switch handle is grounded and that the green wire at terminal 2 seems to have continuity with the switch handle. Is that ok?

i know this is all really hard to diagnose like this, thanks for your time and help
if i cant figure anything out ill try to take some more photos so you can see exactly whats going on
this site is the best!
john

[kngkong]

ok, i double checked. scratch what i said about the green wire on terminal 2 grounding through the switch. I just checked and i guess its grounding through the generator which i think is correct?

could it be that i dont really have a problem and i should be reading continuity through the points when everything is wired because im reading continuity from the points arm lever through the coil up to to terminal 8 through the light and then down to the oil switch when the engine isnt running because there is no oil pressure? If that isnt right im still unsure how to wire those bulbs without completing a circuit from the points lever.

hope this makes sense. appreciate the help

i guess ill just leave the bulbs out until i get this figured out but would be nice for them to work

[FlatHeadSix]

John,
It sounds like everything is normal. It is exactly as you guessed, when everything is connected you are reading the resistance of the components (the bulb filaments, the ignition coil, the generator field coils, etc.), it probably is NOT a short or any other problem. To check if any of the separate wires are shorted to ground you have to disconnect them from their various components and test them independently as I mentioned above. Wire your bulb sockets to the terminal posts above and below each socket, it should not matter which wire goes where. The terminal post below the "GEN" light gets the wire which goes to the relay, the terminal below the "OIL" light gets the wire which goes to the oil pressure switch. To prove your theory you can run the same continuity checks that you have been but try this: remove the "GEN" bulb and test it again, once with the points closed and then again after you have bumped the engine until the points are open. See the difference?, it will show you that the coil has continuity and if you are using a digital ohm meter it will show you how much resistance it has.

One thing you should check carefully is that none of those terminal posts mounted in the dash plate are shorted to ground or that any of the flag terminals on the wires connected to them are touching anything that they should not be. Again, to do this right, you will have to disconnect some of the components from the terminals so that you are testing ONLY the terminal itself.

good luck, keep us posted,

mike

[kngkong]

John,
It sounds like everything is normal.

mike

Hi Mike. Thanks I like that answer the best

I have checked those terminals for grounding and everything checks out so I guess I'll put the bulbs in and give it a try. I was just worried something was wrong and i didnt want to mess anything up if so.

is it suggested to add a fuse into the system? is 20 amps a good amperage to start with?

Will keep you posted.
Thanks a lot!
john

[john HD]

john

yes a fuse is a good idea.

i have run an automotive type blade fuse on my pan for years in the battery positive wire.

i use a 30 amp fuse, but i run spots and a couple of other lights.

you should be fine with a 20, run whatever is common and available at any gas station or quickie mart.

john

[rodklop]

Hi John.... A question about fuses. I have a 48 Pan wired to factory spects. I run a 15 amp
glass fuse between the battery neg. terminal and the ground screw. Is there a right or wrong way to
hook up? Or would it work equally well on either side of the batt. I've run it this way for many years.
Thanks...Rod

[FlatHeadSix]

Rod, (and John)
The fuse will be equally effective on either side of the battery as long as it is place directly between the battery and any other part of the circuit. A fuse or a circuit breaker is ALWAYS a good idea. (unless it is one of those fuseable links that the automotive people like to hide in obscene places that you can't find or easily replace).

mike