Overcharging (with Shindengen R/R)

[Redman]

Am overcharging.



15.5 to 15.8 volts

Was all okay a few weeks ago. I checked thing over fairly well in mid May.


Have a Shindengen (honda, Dunnage) R/R with the sense wire tapped into the orange/green wire of the brake switch circuit (instrument fuse circuit). Have found that to now be less than the battery votage, so that why R/R is overcharging. If I disconnect that sense wire the voltage goes into high 16s, so R/R is doing its thing.

Without bike running, but key on, so current flow to instrument circuit, I have a volt drop of about 1.5 volt from battery+ to the sense wire (brake light circuit).

12.4 at bat+, 10.9 at the org/grn wire to brake switch were sense wire is connected in.


I will track this down tommorow (predicted hottest day of year).

Am just thinking out loud here.
Maybe start at the fuse block. See if volt drop is before the fuse block (that is the ignition switch). Then see if voltage drop is specific to the instrument fuse, or also the other two fuses. Or if voltage drop is after the instrument fuse and out in the wiring harness.

Anybody have any good suspect?
Area around the fuse block connector is oily.


.

[rustybronco]

The connector at the ignition switch on my 80 850 was melted and had to be bypassed. I suspect that might be an area to be mindful of.

[Steve]

Cleaning all the connections is a good first step, but don't rule out the possibility of re-wiring just a bit.

To take some of the strain off the contacts in the ignition switch, you can install a relay to feed the fuse box. Either cut the orange wire that feeds the fuse box or remove it from the connector. Use the part of the orange wire that came from the ignition switch to trigger the relay (pin 86), connect the other part of the orange wire to feed the fuse box (pin 87). Connect pin 30 to the battery (use a fuse, of course, 15 amps should be fine), connect pin 85 to a ground point.

There is a decent chance that will raise the voltage at your sense point, if nothing else works.

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[bwringer]

Yeah, what Steve said. I like to wire these with a relay, because it's damn near impossible to find a good place for the sense wire that doesn't suffer from a decent voltage drop. Plus, the relay circuit is handy for other stuff.

Not sure if you've done this, but you can test the R/R by temporarily connecting the sense wire directly to the positive terminal of the battery. The voltage should fall into line nicely.

[tom203]

If you'd like to ride and escape heat, as a short term fix, just connect sense wire to battery positive. With ignition off, the draw of the sense wire was .0004 amp on two Shindengens that I checked- i.e. insignificant.

[Redman]

.....
....
Not sure if you've done this, but you can test the R/R by temporarily connecting the sense wire directly to the positive terminal of the battery. The voltage should fall into line nicely.

If you'd like to ride and escape heat, as a short term fix, just connect sense wire to battery positive. With ignition off, the draw of the sense wire was .0004 amp on two Shindengens that I checked- i.e. insignificant.

Yep, am aware of this.

With sense wire disconnected, (so R/R see zero volts) the R/R puts out as much as it can and battery volts is 16 or more.

With scense wire to battery+ then battery volts is what would expect.
And current draw when bike is off is okay for a couple days, but will be a problem for longer term. I dont specifically recall, but I did check that once, and I recall it being something like 20-30 milliamps (like 0.020 amps).

I was thinking of relay mod for just the sense wire (and ignition coil power), but that is just avoiding the problem of the volt drop somewhere (ignition swtich or fuse box probably), and the volt drop still exists and something heating up someplace and probably get worse over time.

Ah, Steve and Brian are suggesting a relay mod for the entire main Orange circuit. Ah, removing the main current draw from having to go thru the ignition switch. Ah..... okay, good idea. So, I take that as another vote for the ignition swtich or connector being a good suspect for where I migt find this volt drop.

Ah, I will troubleshoot further to see if volt drop is at igntion swtich, or fuse box, or just on the signal circuit. Then dedcide what to do.

Other adventure this morning was catching a big racoon in trap in garage overnight, and car barley starting. So was working on that. And relocating Mr Racoon. Now to the bike before it gets too hot in garage.

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[Redman]

Without bike running but key on (so had some current flow) I had about 1.5 volt drop from battery+ to the org/grn wire for the brake swtich circuit (were R/R scense wire tapped into). If I pulled headlight fuse, so reduced total curent flow but still had current flow of instruments and tail light ectera, I still had 0.7 volt drop, so still had a symptom to troubleshoot, so was able to narrow down where the voltage drop is happening.

Yep, voltage drop is between the red wire ("leaving" fuse box, going to ignition swtich) and the orange wire ("coming back" to fuse box from the ignition switch).

Will take a look to see if maybe a problem at ignition switch connector. Not too easy to get at on a GK. But I suspect the problem is more likley the contacts in the ignition swtich itself, and maybe no good way to spray in any contact cleaner anyway.

So, seems like the main power relay mod will be a good idea. I got 24vdc and 120vac relays (work related) but no 12vdc realys, so might need trip to auto parts store. But first, lets see if any bad connection at ignition switch connector.

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[surviverguy]

The orange brake wire you're currently using for a sensing wire is a good wire to use to "energize" a power relay. I tried everything to eliminate my voltage drops...then just wired a power relay like others have suggested.

[Redman]

The orange brake wire you're currently using for a sensing wire is a good wire to use to "energize" a power relay. I tried everything to eliminate my voltage drops...then just wired a power relay like others have suggested.

Ah, a few things we could discuss about your comment;
- the orange wire is not the brake circuit.
- the orange wire is the switched main comming back from ignion switch that powers the head fuse, the ignition fuse and the signal fuse.
- the orange/green wire is the brake light switch circuit often use for sense line.
- the brake switch circuit (org/grn) would not be good to operate a power relay if are intending to have the relay power the three fuses, since one of the three fuses is what powers the brake switch circuit.
- the brake switch circuit (org/grn) would be good to operate a relay if just trying to switch the sense wire or ignition coils or maybe some auxillarly thing like maybe some extra lights that dont want to be left on.
- my voltage drop is in the ignition switch, do not know if can get that apart to clean any contacts, but suspect not. So, like you, will not be able to correct that.


To repeat what Steve and others said, and what I am intending to do is:
- have the orange wire from ignition switch operate a relay coil.
- And have the relay contact switch the power to the fuse box (were orange wire used to go) .. and the sense wire.
- So then the ignition switch contact does not have all the head+ignition+signal current going thru it. The ignition switch contact will operate only the relay coil.


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[Billy Ricks]

Something went haywire with my ignition switch years ago and my rear parking/tail,license plate lamp wasn't lighting. It turned out to be inb the ignition switch as with a jumper I fixed that. I should do this mod too.

[tom203]

Redman said.....

"With scense wire to battery+ then battery volts is what would expect.
And current draw when bike is off is okay for a couple days, but will be a problem for longer term. I dont specifically recall, but I did check that once, and I recall it being something like 20-30 milliamps (like 0.020 amps"

When I get ambitious ,I will recheck, but I remember checking my meter at the time - a LED drew .018 amps (at 3 volts), while the sense wire drew .0004 amps. This was a 30 yearold Shindengen SH-232

[Redman]

......
When I get ambitious ,I will recheck, but I remember checking my meter at the time - a LED drew .018 amps (at 3 volts), while the sense wire drew .0004 amps. This was a 30 yearold Shindengen SH-232

I was going to check also. Wonder if the scense line draw is different with bike parked verse with engine running.

.

[Redman]

So

Probelm 1: charging at 16 volts.

Probelm 2: 1.5 to 1.7 volt drop thru ignition swtich.

Probelm 1 is really a symptom of problem 2, due to where/how the scense line is connected.

So to take care of problem 1, I have added a relay to swtich the sense line.



Ran aux power to relay contact, and relay contact swtiches that to the sense line.
Ran the org/grn (brake circuit power) to the relay coil, and grounded the relay coil to the aux negitive.
Could do all that without hacking up the wiring harness.

Got a 40 amp relay (meant for lights or horn) so I can later use it to swtich the main power.

To fix problem 2, need to do like what Steve and Dale and Brian have suggested. And that is to have the ignition swtich (orange wire) operate the relay (and the relay only), and have the relay contact swith the main power (red) to the fuse panel (were org wire is now). Am trying to think how to do that without hacking up the wiring harness. (have an idea in mind).

Dave