Custom Tach Adapter Wiring Query - VTXOA
Reply
 
LinkBack Thread Tools
post #1 of 11 (permalink) Old 05-17-2017, 11:00 AM Thread Starter
Senior Member
 
Join Date: Sep 2015
Location: Ontario, Canada
Posts: 113
Custom Tach Adapter Wiring Query

Hello

End of last season i bought a Baron tach adaptor that I installed last week. It fails out of the box. My late googling seems to show that that is a typical thing, So I thought about making my own. Attached is the wiring diagram that consistantly shows up. However, my issue is that it shows everything in parallel. If there is the diode in there to regulate current flow direction, doesn't the parallel configuration effectively bypass the diode thru the resistor? I feel it should be coilwire->diode->resistor->tach wire for both sides.

I am asking for feedback before I try the series configuration so I do not risk my computer !

thanks
Attached Images
File Type: jpg TachAdapter-1.jpg (163.6 KB, 21 views)
Mastertechie is offline  
Sponsored Links
Advertisement
 
post #2 of 11 (permalink) Old 05-17-2017, 12:38 PM
Senior Member
 
Harkon's Avatar
 
Join Date: May 2010
Location: Calgary, Alberta, Canada
Posts: 1,414
Those are 100K ohm resistors. You won't get much signal to the tach with those resistors in series. My guess is that the resistors are likely not needed 100% of the time, but depending on the driving circuit, it does put the tach at the coil potential. IOW, it doesn't hurt having them in there and will allow the tach to see a logical high (if it needs it).


'12 Road Glide Ultra, Kuryakyn Alley Cat intake, Screamin' Eagle Fatshotz slip-ons, V&H Dresser Duals, PV Tuner, NDana HID kits
Harkon is offline  
post #3 of 11 (permalink) Old 05-18-2017, 06:15 AM
Senior Member
 
Hans&Feet's Avatar
 
Join Date: Jun 2005
Location: Conyers/McDonough, GA
Posts: 8,254
Garage
The diodes are blocking the +12v and peak voltage.
I suspect the tach puts out +5 or +12 volts with a pull up resistor and the diode is forward biased when the coil is grounded.
The resistor may be used to discharge the circuit or is the pull up resistor.
My 2
Attached Images
File Type: jpg IGN coil voltage-Oscilloscope8964.jpg (321.0 KB, 9 views)

2005 1300c Red, Mustang seat, HK 2.5 straights. Leds for safety-front & back. 180,596 miles of smiles

Last edited by Hans&Feet; 05-18-2017 at 06:24 AM.
Hans&Feet is offline  
 
post #4 of 11 (permalink) Old 05-22-2017, 02:53 PM Thread Starter
Senior Member
 
Join Date: Sep 2015
Location: Ontario, Canada
Posts: 113
well I tried it and did not get the results I wanted. It seemed to show double the idle rpm and when revved up it lagged and then would not get up there or drop to 2000 and sit there. Also had alot of needle bounce.

Oh well. thanx for the insights and I did not fry anything,
Mastertechie is offline  
post #5 of 11 (permalink) Old 05-22-2017, 05:34 PM
Senior Member
 
Hans&Feet's Avatar
 
Join Date: Jun 2005
Location: Conyers/McDonough, GA
Posts: 8,254
Garage
It has been a long time since this came up.
If the tach is made to connect direct to the Ign coil, then reverse the diodes and the high voltage
spike should go to the tach. The down side would be the +12v from each coil would be gated to the tach also
for a long duration. Put the resistors in series with the diodes and try that.

2005 1300c Red, Mustang seat, HK 2.5 straights. Leds for safety-front & back. 180,596 miles of smiles
Hans&Feet is offline  
post #6 of 11 (permalink) Old 05-23-2017, 11:39 AM
Senior Member
 
Harkon's Avatar
 
Join Date: May 2010
Location: Calgary, Alberta, Canada
Posts: 1,414
At this point I think it would be very helpful to see what the tach manufacturer woudl like to see for a hookup and what bike this is actually for. Then it would be easier to come up with an "adaptor". Without that, it's all just a guess.


'12 Road Glide Ultra, Kuryakyn Alley Cat intake, Screamin' Eagle Fatshotz slip-ons, V&H Dresser Duals, PV Tuner, NDana HID kits
Harkon is offline  
post #7 of 11 (permalink) Old 05-23-2017, 05:01 PM Thread Starter
Senior Member
 
Join Date: Sep 2015
Location: Ontario, Canada
Posts: 113
Quote:
Originally Posted by Harkon View Post
At this point I think it would be very helpful to see what the tach manufacturer woudl like to see for a hookup and what bike this is actually for. Then it would be easier to come up with an "adaptor". Without that, it's all just a guess.
sadly there are no manufacture marks on this
Mastertechie is offline  
post #8 of 11 (permalink) Old 05-23-2017, 07:48 PM
Senior Member
 
rangers4u's Avatar
 
Join Date: Jul 2011
Location: Salix, Pa.
Posts: 4,883
Quote:
Originally Posted by Mastertechie View Post
sadly there are no manufacture marks on this
I don't know if this will help you or not. I bought a Rivco setup, with a VDO brand tach, some time ago. I suspected when I bought it, it was for a 1300, not an 1800. After making several calls, I was lucky to get the little black box adapter for the 1800. Until last Tuesday, I had no wiring instructions, but now I do, and thanks to Chuck_VTX_F I now have a working tach. If you would like a copy of the Rivco instructions, PM me with your email, and I will forward them. You're welcome.

2003 1800C Black w/ H-K 3", PC III, Hondaline w/s & backrest, XM sat. radio, MB 12" shocks, Progressive fr. spgs., Wolo, SPyKER mod, Glen's gas cap, Paladins, Drag Specialties Popsicle pegs, K-N, blackened engine, Kury RTB, mirrors & r. boards, blue LED's, Rivco tach & risers, LeatherLyke bags, backrest bag, w/s tri-pouch, desmog, pr. valve mod, grd. fix, Gen. Altimax RT43, Mich. Cmdr. II, Ult. Lowrider, Showchrome grips.
rangers4u is offline  
post #9 of 11 (permalink) Old 05-25-2017, 09:32 AM Thread Starter
Senior Member
 
Join Date: Sep 2015
Location: Ontario, Canada
Posts: 113
Quote:
Originally Posted by rangers4u View Post
If you would like a copy of the Rivco instructions, PM me with your email, and I will forward them. You're welcome.

PM sent. Thank you
Mastertechie is offline  
post #10 of 11 (permalink) Old 05-28-2017, 05:43 PM
Junior Member
 
Join Date: Jul 2016
Location: Fort Worth, TX
Posts: 8
You're better off buying a tach adapter off Fleabay that uses the dip switches which allow for just about any combination of motor/tachometer. The one I bought was about $50 and has a signal doubler so it's only hooked to one coil.

I bought one last year as I was doing the homemade tach adapter route and eventually burnt up my first Baron after about 6 months. Too much needle jumping eventually sent it to the grave I guess. New one has been pretty much flawless.

Sent from my VS986 using Tapatalk
BigTex03 is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the VTXOA forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome