Frame Ground vs Block Ground

[Rio Wil]

Just a curiosity......I have not had a need or opportunity to have my bike dismantled to the point I can identify the ground circuit wiring other than to the obvious connection of from the batter neg to the block (ie, block ground). The starter, alternator, etc are referenced to block ground. I am not aware of any devices that have their ground connection to the frame (ie, utilizing a terminal and screw of some sort). Like I said, I have not had my bike apart to the point of exposing all the wiring harness and possible terminal/screw/frame connections.

Having said that, I did install an after market horn utilizing a relay and did use a frame ground (connector and screw) for the ground circuit for the relay coil as well as the ground for the horn its self.

So the question becomes, where is the block ground tied to the frame ground.  Is there a big knarley ground wire hidden somewhere that goes from the block to the frame, or, is this ground accomplished by the various bolts between the block and frame ......like the engine mount bolts, the exhaust mounting bolts, etc.

Some have reported moving the battery ground from the block to the frame and then later adding a frame to block cable. Others have done the opposite (but electrically the same) adding a cable from  the block to the frame.  

If the frame ground is through the various mounting bolts and not a nice hard wired cable, I wonder if the infamous 1/4 second total ignition failure some of us have experienced about once a year is due to a potential that builds up between frame ground and block/battery ground.....causes a "arc" and disrupts the ECU for a moment and we get the hiccup.........

A secondary question is: should it be standard procedure to add a block to frame cable as a matter of course for bikes with the age of our phat ladies.....

[RP#62]

This may help some.
-RP

http://www.rattlebars.com/valkfaq/schematics/rpage09.html

[Rio Wil]

Hmmmm, not really.....this is pretty much just a schematic redrawn.  I see some notations that reference the ground point, ie, block, fan frame, etc.  These two would represent a block ground and a frame ground.......it doesn't speak to what connects the frame and block ground......

[Firefighter]

Don't know, but I had all kinds of problems. I have three extra gauges that used to go crazy, especially when the radiator fan turned on. If I idled slow putt putt around the engine would start to miss. This forum, especially RP#62 helped me. I checked the battery ground and found nothing wrong. I looked a little but found no frame ground. Big difference in battery voltage when checked at the battery or checked at the frame. I ran another ground from battery to frame, and never any trouble since. So my frame was not grounding correctly and alot of critical things are grounded by the frame. This site is the best, makes for a good reason to own a Valk!

[MarkT]

As I've said before, but just to put it in this thread:  I had a breakdown on the road that was caused by the bad ground battery-block.  I moved that wire to the left footpeg mount.  And added a big grounding strap block-frame when I got home.  Never a problem since.  Have read many reports of others who had the same problems caused by that poor ground to the aluminum block.  I have also experienced other problems all caused by poor grounds to aluminum.  Aluminum oxidizes and that can add a LOT of impedence to electric flow.  The official fix is to use those star washers that dig in on the aluminum.  I try to bypass the problem where it makes sense and just move the ground to steel.  If you HAVE to connect a ground to aluminum - use a star washer.  I also use connection compound made for connecting to aluminum.

[RP#62]

Hmmmm, not really.....this is pretty much just a schematic redrawn.  I see some notations that reference the ground point, ie, block, fan frame, etc.  These two would represent a block ground and a frame ground.......it doesn't speak to what connects the frame and block ground......

It can only show what's there, which is what you asked.  The battery ground connects to the engine.  The harness ground connects to the thermostat housing.  Then engine IS the connection from the battery ground to the harness.  The thermostat housing ground also connects to the frame at the 1/2 coil bracket.  That becomes the path from the battery ground through the engine to the frame.  That's all there is.

-RP

[Rio Wil]

Hmmmm, not really.....this is pretty much just a schematic redrawn.  I see some notations that reference the ground point, ie, block, fan frame, etc.  These two would represent a block ground and a frame ground.......it doesn't speak to what connects the frame and block ground......

It can only show what's there, which is what you asked. 

(It shows numerous grounds with no distinction as to what is the ground reference point...other than the two I mentioned)

The battery ground connects to the engine. 

(Agreed)

The harness ground connects to the thermostat housing. 

(Now we are getting somewhere....is it  multiple wires or just one larger one from the harness and does it use one of the thermostat housing bolts to secure it...them?)

Then engine IS the connection from the battery ground to the harness.

(agreed....since the battery ground attaches to the block/engine)

  The thermostat housing ground also connects to the frame at the 1/2 coil bracket. 

(So there is a wire that runs from the thermostat housing to the frame and attached with a screw/bolt?? at the 1/2 ign coil)

That becomes the path from the battery ground through the engine to the frame.  That's all there is.

-RP

RP....thanks for your comments......

Wil

[RP#62]

Its been a while since I've been into it that far, but I believe the ground at the thermostat housing is connected with a ring connector to one of the mounting bolts.  It has a single wire going to it that goes (through some connectors and harness splices) to the ring terminal at the 1/2 coil bracket.  Its crimped with another wire in the coil bracket ring connector and that other wire is the harness ground. 

Now that I've looked at it more it does seems that that is a screwy way to do things.  At some point I may run a separate ground from the battery ground to the frame and from the frame to the headlight bucket.
-RP