Honda CX 500 Forum banner
1 - 20 of 38 Posts

·
Registered
Joined
·
18 Posts
Discussion Starter · #1 ·
I know this question is asked a lot, but I’ve done a lot of googling and searching through the forum and I can’t find an answer on how to hook up an electronic tach on a gl500 or a TI ignition cx500. Everything i’ve found is on the cdi and usually involves using an ignitech. I decided to try out some cheapish all in one gauge off amazon. I’ve tried hooking up the ignition signal wire (the instructions say to hook up to “positive ignition” (whatever that means). I tried hooking it to the signal wire from the ignitor, the main coil/ignitor power, and to one of the wires from the pickup coil. None made the tach budge. Does anyone know where i can hook it up? or something i can buy to make it work?
Thanks in advance!
208533
208534
 

·
Registered
1982 GL500i
Joined
·
483 Posts
Might make better sense if I could see the whole schematic sheet instead of the close-up provided. It may have a lot to do with the era of bike the tach was intended for.
 

·
Registered
Joined
·
18 Posts
Discussion Starter · #5 ·
i’m not familiar with what the cdi pickup looks like, but on my bike there’s 4 wires coming from the pickup, 2 to each ignitor chip. i tried tapping into 1 of the 4 and revd the bike up and the tach didn’t move
 

·
Registered
Joined
·
18 Posts
Discussion Starter · #6 ·
I have the same instrument on one of my bikes {CDI though}. It takes its tach signal from one of the low speed pickups.

No life from the TI pickup?
(referring to my earlier reply) assuming that’s what u meant by low speed pickup anyway
 

·
Super Moderator
Joined
·
23,099 Posts
Try the other for the same side.

I'm not familiar with the TI operation but if one is high and one is low the high speed may not send a signal until the system switches over to high speed.
 

·
Registered
1982 GL500i
Joined
·
483 Posts
Ok, I see the problem now. The instructions are written in Chine-Glish. All I can say is "rotsa-ruck" making sense of it, lol!
 

·
Registered
Joined
·
18 Posts
Discussion Starter · #9 ·
Try the other for the same side.

I'm not familiar with the TI operation but if one is high and one is low the high speed may not send a signal until the system switches over to high speed.
Alright Ill try that. I didn’t realize there was potentially 2 different signal types for the wires coming from the pickup. Thanks
 

·
Registered
1982 GL500i
Joined
·
483 Posts
Honestly, inductive timing lights have been around for decades. Why they don't use the same for aftermarket tachometers is beyond me.
 

·
Registered
Joined
·
18 Posts
Discussion Starter · #12 ·
Ok, I see the problem now. The instructions are written in Chine-Glish. All I can say is "rotsa-ruck" making sense of it, lol!
yea, i’ve wired a few tachs before, i didn’t give it much thought and ordered it figuring as long as I had the wire colors i’d be fine. Anything i’ve used in the past has always hooked up to a coil signal. Not sure why this is any different.
 

·
Registered
1982 GL500i
Joined
·
483 Posts
Any electrical tachometer for any motor need to count ignition pulses somewhere, at the coil or on an inductive coil placed around a plug wire. Since this tach does not have an inductive coil with it, a positive ignition coil terminal should do. The trick to getting the thing to "count" properly, is knowing how to set up the internal tach program once installed. Older analog tachs had a manual switch to set to the correct number of engine cylinders. My guess is that the digital tach has to be properly programmed after installation, or it might not do anything at all, as you have mentioned. I would not even trust the program to take into account the "total loss" ignition systems found on many older twins, as it may not be able to divide the total number of pulses by 2. Having instructions that are difficult to interpret doesn't help matters either. You may just have to experiment until you get it to respond.
 

·
Registered
Joined
·
18 Posts
Discussion Starter · #15 ·
Any electrical tachometer for any motor need to count ignition pulses somewhere, at the coil or on an inductive coil placed around a plug wire. Since this tach does not have an inductive coil with it, a positive ignition coil terminal should do. The trick to getting the thing to "count" properly, is knowing how to set up the internal tach program once installed. Older analog tachs had a manual switch to set to the correct number of engine cylinders. My guess is that the digital tach has to be properly programmed after installation, or it might not do anything at all, as you have mentioned. I would not even trust the program to take into account the "total loss" ignition systems found on many older twins, as it may not be able to divide the total number of pulses by 2. Having instructions that are difficult to interpret doesn't help matters either. You may just have to experiment until you get it to respond.
yea i think the extent of the programming is selecting whether it’s a 2 or 4 cylinder from a menu thing
 

·
Super Moderator
Joined
·
23,099 Posts
Keep in mind that these have a redundant spark so they spark twice as often. You will be reading the pulse from one cylinder though.

I have the setting I used written down in the shed if you need it.
 

·
Registered
1982 GL500i
Joined
·
483 Posts
Yeah, the more I look at the schematic supplied, the less it makes any sense. If you do get it to work, be sure to charge a premium to anyone else who wants theirs to work too, lol!
 

·
Registered
1982 GL500i
Joined
·
483 Posts
OK. My Chine-Glish is working a little better now. It looks like the instructions say to connect the black/yellow wire to your ignition trigger source. It might not like a high-voltage connection at the coil, as Phreak has mentioned above. The only other option is one of the pulse coils from the crankshaft. Which wire that might be is what you have to figure out.
 

·
Registered
Joined
·
438 Posts
that gauge should work with the signal on the coil - use one of the coloured wires where they go to the coil - not the black with the white stripe - but the other one.

Rayman
 
  • Like
Reactions: CXPHREAK

·
Registered
Joined
·
18 Posts
Discussion Starter · #20 ·
that gauge should work with the signal on the coil - use one of the coloured wires where they go to the coil - not the black with the white stripe - but the other one.

Rayman
that’s what i originally thought, but something might’ve been wrong connection wise, after work today im gonna go through and make sure everything is making good contact and i’ll try the signal wire again
 
1 - 20 of 38 Posts
Top