Replacing Suzuki 8-pin ignition switch

adventurco

Nick Ol' Eye
DTT BOTM WINNER
The ignition switch on the RV125 was missing when I got the bike. Since it is unobtainium, I grabbed one of the universal 4-wire EMGO replacements since I have used them on a few bikes and had good luck. I’m trying to figure out how to wire this up.

From what I can gain, with the OEM switch, position 1 turns on the ignition and aux power (horn, neutral light, etc) which is powered by the battery. Position 2 activates the lighting coil from the magneto to power the headlight and taillight.

The EMGO switch does have an off, I and II position but I believe Honda used position 2 as no ignition, lights only.

So I’ve been scratching my head on this one. Not sure if the best way is to make it so the ignition, headlight and taillight are all activated at the I position (effectively jumping the connections in the OEM ignition switch diagram).Do I need any kind of resistor if I jump those connections.

Any input appreciated. See pics below

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The ignition switch I’m using (has Honda red, black, brown and brown/white wires)

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don't know if this helps but when I had my GS750 keys confiscated by the cops (that's another story) I had to wire in a CB750 a/market ignition key to get it going again and after that it would only run with the lights on, never understood why but it worked so I didn't worry too much
 
OK... headlight looks to be AC, so this might get tricky unless you wanted to do a DC conversion. Most of the additional wires in the ignition switch are to help balance the charging requirements versus the power requirements (your bike has no voltage regulator, so the output of the alternator needs to be fairly close to the wattage your bike is using at any given time).

I'm going to assume that we're running with all lights on all the time and I highly recommend the installation of a voltage regulator (combined R/R would be best).

Here goes:

Red wire on the ignition switch to match up with red wire on the harness, coming from the battery (fused)
Black wire on the ignition switch to split and go to the following wires in the harness: Horn (brown), tail light, and an added automotive relay.

On the new relay, the pinout will be as follows:
85 - From black wire on ignition switch (mentioned above)
86 - Ground
87 - Headlight wire (gray? blue?)
30 - C3 from stator (red/yellow)

For the charging system changes, grab a single phase regulator/rectifier from our site. Yellow/white and green/white (normally unused, I think?) go to yellow and pink on the R/R. The red from the R/R goes to the battery positive terminal and the green wire gets grounded. Black wire from the R/R should connect to black wire from the ignition switch.

If you want to get really fancy, relocate the green/white wire in the stator and resolder it on the opposite end of the winding, after floating the ground. This will increase the charging capacity of the bike.

If you wanted a DC conversion, skip the automotive relay mentioned above and go with a three phase regulator/rectifier. The red/yellow wire now leads to the third leg of the R/R and not the relay. You'll lose half the power output of the winding if you don't float the ground, so it might be worth swapping over to LEDs.
 
I’m a bit confused here, not sure why we need to add a r/r and an automotive relay, as I am keeping all the electronics stock.

I don’t think that the ignition switch that I have will work in this application. I think I’m better off adding a couple of toggle switches, one dpst for ignition and one dpdt for the lights. I want the headlight to have an off position as well so there is sufficient power for starting.




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Is it unobtanium, or do you not want to pay the going rate? It's a lot, just making sure you haven't overlooked some listings or if the years aren't compatible.

https://www.ebay.com/itm/Suzuki-RV125-RV90-SP370-TC100-TC125-TS100-TS125-TS185-TS250-Ignition-Switch-NOS-/310490732700?_trksid=p2385738.m2548.l4275

https://www.ebay.com/itm/Suzuki-TC100-TC125-TS125-TS185-TS250-SP100-SP370-Ignition-Switch-NOS-/112620786317?_trksid=p2349526.m4383.l4275.c10

https://www.ebay.com/itm/Suzuki-TC100-TC125-TS125-TS185-TS250-RV90-RV125-SP370-Ignition-Switch-NOS-/112622214392?_trksid=p2349526.m4383.l4275.c10
 
irk miller said:
Is it unobtanium, or do you not want to pay the going rate? It's a lot, just making sure you haven't overlooked some listings or if the years aren't compatible.

I did see those, they’re expensive and I’m just not sure they are correct. According to the diagram for the switch there should be 8 wires coming from the switch to the connector, and in all of the eBay listings they only seem to have 4 wires. Tough to tell as the photos aren’t that great.
 
https://www.ebay.com/itm/New-OEM-Suzuki-Savage-TS250-Ignition-Switch-37110-16410-37110-16411/192360481585?hash=item2cc9940331:g:Tt8AAOSw9gRaBded&vxp=mtr

https://www.ebay.com/itm/SUZUKI-SP-SP370-GT-GT200-GT250-GT500-GT-500-GP125-37110-28655-IGNITION-SWITCH/382237448198?hash=item58ff209806:g:zLIAAOSwStxZy9t3&vxp=mtr

https://www.ebay.com/itm/GP100-125-GT200-X5-GT250-X7-SP370-GT500-Ignition-Switch-Assembly-37110-28655/161138022360?fits=Make%3ASuzuki%7CModel%3AGT500&hash=item25849317d8:g:0lQAAOSwq8BZbTFe&vxp=mtr

https://www.ebay.com/itm/Suzuki-FZ-50-X-Suzy-1981-0050-CC-Ignition-Switch/390595516315?_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D2%26asc%3D49478%26meid%3De95ac5d9536c4d67b9c3a2ebcc5cf95e%26pid%3D100005%26rk%3D5%26rkt%3D6%26sd%3D352203019694&_trksid=p2047675.c100005.m2219

https://www.ebay.co.uk/itm/Suzuki-GT50-K-Ignition-Switch-New-Old-Stock/352196648634?hash=item52008e5eba:g:Ad0AAOSwKOJYGfff

https://www.ebay.co.uk/itm/Suzuki-FZ50-Ignition-Switch-New-Old-Stock/352203019694?hash=item5200ef95ae:g:Me8AAOSwx2dYGe-R

https://www.ebay.co.uk/itm/SUZUKI-AP50-FITS-A50P-1970s-IGNITION-SWITCH-NEW/253243637030?hash=item3af67f3d26:m:ma3bA2hxUdaM6OHdD_nR2SQ

https://www.ebay.co.uk/itm/New-Nos-Suzuki-8-Wire-Main-Ignition-Switch-2-Genuine-Keys-P-No-37110-46711/253262146001?hash=item3af799a9d1:g:qtsAAOxyrxZR3SZW
 
Thanks for the links. I think a few of those may be close but this is the only one that;s a direct match. $90 :-\

https://www.ebay.com/itm/NEW-GENUINE-SUZUKI-RV90-RV125-FACTORY-IGNITION-SWITCH-ASSY-37110-26616/172808683665?hash=item283c334091:g:-SEAAOSwEgZZhhyn&vxp=mtr
 
I'd pay the money. For all the great work you've done on this thing, this is just a drop in the bucket. I understand though. I approach things the same way.

Babbitt's has it for a few bucks cheaper https://www.suzukipartshouse.com/oemparts/p/suzuki/37110-26612/switch-assy-ignition
 
advCo said:
I’m a bit confused here, not sure why we need to add a r/r and an automotive relay, as I am keeping all the electronics stock.

Sorry. Looks like I misunderstood the requirements.

The answer is that you're going to need the stock switch. Too much logic baked into that bit of hardware if you're looking to keep everything else as is.
 
Thanks for the input guys. I was able to contact the ebay seller for the NOS switch and get it for $60 with free shipping. Should be able to get the old girl up and running as soon as it arrives.
 
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