1932 VL rewire/instrument panel rebuild

[loch]

I'm starting a new thread separate from the Venturi thread because the topics are significantly divergent. Moreover, assembly of the instrument/switch panel is only covered in any kind of detail in Steve Slocumbe's book. But still I found it took some fiddling with the parts to find the correct fit for the instrument light.

Someone might benefit from this discussion later.

This mornings efforts resulted in two unanswered questions.

1. Which terminal on the ammeter is positive and which is ground?
2. Is there anyway to create some tension in the light assembly - it seems like the light bulb is just flopping around in the housing. It works, the switch works albeit isn't a very snug fit.

Actually 3 questions.

3. is there such a thing as a single lead horn button? Mine is a two-lead button. I suspect this is incorrect since the wiring diagram (Rider's Handbook 74 and 80 Twin Models, 29) shows only a single lead from the horn button.

Cheers,
Lochlain

[tfburke3]

There is no ground wire on an ammeter.the meter measures the current flow by being in series with the main wire to the battery positive.If you connect it backwards the reading will be + with some load and bike not running.
tom

[Peter Cooke]

Here's the wiring diagram. The changes from headlight switch to terminal #7 only apply if you convert to a 2 brush generator and electronic relay.

image_31486.jpg

[Steve Slocombe]

For the bar and shield ammeter, the left terminal is grounded through the dash base plate and then the forks. The white ammeter 1934-onwards is upside down with the ground on the right. Harley then advised running a separate ground wire to the 3344-25 clip on the top left of the frame, and doing the same for earlier bikes. The 1934-36 wiring diagram in the Owners Handbook is incorrect as the ammeter has been changed but not the ground connection. A 1935 Shop Dope reports blown headlamp bulbs with the separate ground wire as the fix.

Check your dash lamp plug 4574-29, as this has springs under the contacts to tension the bulb.

Yes the taller horn switch has two wires and I take a quarter point hit for this on judged VLs. The lower single wire horn button is available as a repro for more money.

[loch]

Thanks Steve, I found a source for the repo single wire horn switch.

Interesting notes on the wiring.

For the bar and shield ammeter, the left terminal is grounded through the dash base plate and then the forks. The white ammeter 1934-onwards is upside down with the ground on the right. Harley then advised running a separate ground wire to the 3344-25 clip on the top left of the frame, and doing the same for earlier bikes. The 1934-36 wiring diagram in the Owners Handbook is incorrect as the ammeter has been changed but not the ground connection. A 1935 Shop Dope reports blown headlamp bulbs with the separate ground wire as the fix.

I have an older repro ammeter, no bar and shield. It has a white face. But the needle points forward and pivots from the rearward edge of the bezel - not sure if that's considered upside-down or not. Is the grounding to the clip in addition to the other connection from the ground post, or is in lieu of?

Nevertheless I still need to put a power source to it to discover which is the power side which is ground. Interesting discovery after reading the notes on grounding earlier cycles to the clip. Namely, there is no common ground to the frame as indicated by the wiring diagram. I've been studying the diagram for the past few days and just realized this.

- Loch

[loch]

No 30 May 8, 1935 Shop Dope states: "...the grounded side of the generator-battery circuit (from ammeter to generator) was completed through fork fittings and frame head bearings."

Fork fittings and frame head bearings? Does anyone know the details of this works? How is this grounding achieved? The horn and the headlamp are the only components attached at the forks that could possibly create a ground.

[Rubone]

No 30 May 8, 1935 Shop Dope states: "...the grounded side of the generator-battery circuit (from ammeter to generator) was completed through fork fittings and frame head bearings."

Fork fittings and frame head bearings? Does anyone know the details of this works? How is this grounding achieved? The horn and the headlamp are the only components attached at the forks that could possibly create a ground.

The entire frame and everything bolted to it is a ground, only items insulated from the frame are not.

[Jerry]

I am rewiring a '32 VL and have the Rider's handbook and Mr. Slocombe's book with the wiring diagrams. I am stumped about the wiring of the ammeter. It has the yellow wire connected at the right ammeter terminal and the negative battery terminal, and appears to have the left ammeter terminal attached to the dash light. Does that ammeter sense the current going from the light switch from the red wire to the dash light, then to the ammeter? There is a dotted line from the left ammeter connection to the dash light and from the dash light to the #7 terminal on the light switch. I've never seen an ammeter that appears to be wired this way.

[Jerry]

I think I just figured this out in my head. I just realized there are no wires connecting the negative post of the battery to the frame as in every other machine I've ever worked on. The only connection the negative battery post has is through that yellow wire attached to the ammeter. That means to me that the only way for anything on the bike has to get its ground through the ammeter. I understand now why the left ammeter post is grounded and connected to the dash light. I believe this system is just completely backwards to anything I've seen before.

[Peter Cooke]

Hi Jerry,

Correct you are.
If you have Johnny Sells book there is a good description on pages 17-2, 3 & 4 of how the system works. Included is the diagram from Shop Dope 34 showing the underneath of the dash with the lamp to ammeter wire on the left side and an indicator for the yellow battery wire on the right side.

Also included is "From the primary winding of the coil, the current flows through the circuit breaker points to ground. The circuit is finally completed through the ammeter and YELLOW wire of the main cable to the negative post of the battery."

VL Ammeter Wiring.jpg

[Jerry]

Thank you!