Troubleshooting the Grey Wire Issue - Ignition Removal - ZX Forums
 
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post #1 of 6 (permalink) Old 02-06-2017, 10:32 PM Thread Starter
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Troubleshooting the Grey Wire Issue - Ignition Removal

TLDR: How do I get better access to the wiring harness that's between the radiator and headers? I need to disconnect the ignition switch from the wiring harness.

Hey guys, first post here. Hoping I can get some advice on how to disconnect my ignition switch from the wiring harness that's between the radiator and headers. Using THIS post as a guide I was able to remove the ignition switch from the upper triple clamp, without removing the upper triple itself. The security bolts holding the ignition to the triple had previously been replaced with regular hex hardware. Now my issue is gaining access to the wiring hardness that's between the radiator and headers. I need to actually disconnect the switch, and I can't because I don't have space to work.

I've removed the tank, airbox, and some of the smog equipment to make some room. There's a black plate bolted to the head of the motor. It seems like if you remove this plate you would have room to work on the wiring harness. However, it appears that you need to disconnect the throttle cables / remove the carbs to gain enough clearance to remove the plate. I could be wrong, but I've never had to disassemble an entire bike to gain access to one connector. I tried referencing the Kawi service manual without any luck. Does anyone have any advice for me? Should I try dropping the radiator to make room?

I need to pull the ignition to troubleshoot the infamous Grey Wire issue. I backprobed the grey wire with the key in the on position and only saw 5.8 - 5.9 volts to the grey wire before trying to crank the motor. After the I tried to crank the motor the headlights would kick on. Afterwards I would only see 5.2V across the grey wire. I was going to attempt soldering a new 100 ohm (is that the proper resistance?) and cleaning the connections before I bought a new ignition off ebay.

I've attached some pictures to help detail my issue. If there are any 7r experts out there with any advice, I'd greatly appreciate it.






If you are unable to see the images, here's an Imgur link to an album: http://imgur.com/a/Cl2bf
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post #2 of 6 (permalink) Old 02-07-2017, 09:34 AM
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A little hard to tell from the album, but looks like you might get away with just loosening radiator or radiator fan.

Would help to know what year - mine was a 98 and that black plate came off easy.

Taking off everything to get to one bloody component is pretty standard for me, but I have always had bad luck...
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post #3 of 6 (permalink) Old 02-07-2017, 10:01 PM Thread Starter
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I was able to get the ignition off the bike! I ended up pulling the upper faring, and black blockoff plate off the bike to gain access. At the end of the day I could have done without removing the upper faring. But, the bike is absolutely filthy and this will help give better access to wipe everything down. I apologize for the poor photo quality. I figured what I was asking about was clear enough from the text description I gave.

The bike is a 1997 model year with ~34.5k miles on the clock. Now I can only hope that replacing the resistor in the ignition switch will bring the bike back to life. I did notice another thing though, there's a brown wire running from the ignition switch, back to the CDI. The female side of this connector had begun to melt the connector housing enough to make getting the housing apart difficult. Does anyone know what this brown wire is for?

Hopefully I can get a new resistor soldered in and get the bike running.
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post #4 of 6 (permalink) Old 02-16-2017, 10:55 PM Thread Starter
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I finally found time to tear into the ignition tonight. I thought I'd find broken / bad solder joints for sure. However, all I found was lots of old WD-40, light grease, and very minor corrosion. I cleaned everything up with a mix of engine de-greaser for the WD-40 and grease, and rubbing alcohol for cleanup. I decided not to solder in a new resistor immediately since the solder joints didn't look bad. The previous owner of this bike has definitely replaced the resistor before, how likely is it that this resistor has gone bad?

I reassembled the ignition coating the electrical contacts in dielectric grease. Now when I probe the grey wire with the key in the ON position I get 5.95v through the wire. Is that voltage close enough to the 6.0v threshold to allow the bike to start? Before cleaning everything I was getting 5.80v-5.90v through the grey wire. Should I just go ahead and solder in a new resistor / order a new ignition? Is there anything else that can keep the grey wire from getting the 6v signal besides the resistor in the ignition?

I've attached some photos of the solder joints in ignition, and the voltage reading on my multimeter when probing the grey wire.





e: link to album, seems the forum doesn't like imgur links. http://imgur.com/a/5XoNe
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post #5 of 6 (permalink) Old 02-17-2017, 05:07 AM
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Quote:
Originally Posted by 7Rider View Post

I need to pull the ignition to troubleshoot the infamous Grey Wire issue. I backprobed the grey wire with the key in the on position and only saw 5.8 - 5.9 volts to the grey wire before trying to crank the motor. After the I tried to crank the motor the headlights would kick on. Afterwards I would only see 5.2V across the grey wire. I was going to attempt soldering a new 100 ohm (is that the proper resistance?) and cleaning the connections before I bought a new ignition off ebay.
Just a thought, 5.9 volts is pretty close. You should see 6v in a perfect world. Normally the problem with this resistor is that it burns up completely or breaks at the solder joint. Neither is the issue in your case if you're that close to 6v.

Check you battery to make sure you have a full 13v(or more) at the terminals. If your battery were a little undercharged, say, 12v even (or less), you could see less-than-optimal readings at the grey wire terminal.

As a side note, 7Rs don't tolerate low voltage at the battery very well at all. Mine starts hard if I have anything less than 12.75 volts at the battery.

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post #6 of 6 (permalink) Old 02-17-2017, 06:36 PM Thread Starter
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Quote:
Originally Posted by ZX7RJoe View Post
Just a thought, 5.9 volts is pretty close. You should see 6v in a perfect world. Normally the problem with this resistor is that it burns up completely or breaks at the solder joint. Neither is the issue in your case if you're that close to 6v.

Check you battery to make sure you have a full 13v(or more) at the terminals. If your battery were a little undercharged, say, 12v even (or less), you could see less-than-optimal readings at the grey wire terminal.

As a side note, 7Rs don't tolerate low voltage at the battery very well at all. Mine starts hard if I have anything less than 12.75 volts at the battery.
Thank you for the insight and information! I recently put a brand new Deka AGM battery on the bike (YTX12-BS) and the battery has been on a tender while sitting off the bike. I'm getting a solid 13.5v out of the battery when I probe the terminals. I'm going to try and run the bike tonight and see if it decides to start, I'll update the thread once I give it a go.

Anyone else care to chime in on this issue?
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