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Discussion Starter · #1 ·
So, went to start my bike today and nothing happened. More specifically, when I turned the key, no lights, no dummy lights, nothing. Checked the main fuse right away and it was blown. Checked for normal loose wire stuff and nothing. So, popped in a new fuse and not only did it blow again but thought I saw a small puff of smoke come from solenoid. So, removed solenoid and opened it up. Looked fried to me. My question is, anyway to temporarily bypass the solenoid to see if bike fires up or is this a really bad idea? As you can tell I am a very limited in my electrical system knowledge! Saw a new aftermarket solenoid on eBay for $28 specifically for 1980 CX500 so going to get this either way but would like to see if everything else is cool until it arrives. Thanks.
 

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My solenoid is bad in a different way... i press the start button and nothing happens so i put a screwdriver between the posts to short it out and it starts right up
 

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So, went to start my bike today and nothing happened. More specifically, when I turned the key, no lights, no dummy lights, nothing. Checked the main fuse right away and it was blown. Checked for normal loose wire stuff and nothing. So, popped in a new fuse and not only did it blow again but thought I saw a small puff of smoke come from solenoid. So, removed solenoid and opened it up. Looked fried to me. My question is, anyway to temporarily bypass the solenoid to see if bike fires up or is this a really bad idea? As you can tell I am a very limited in my electrical system knowledge! Saw a new aftermarket solenoid on eBay for $28 specifically for 1980 CX500 so going to get this either way but would like to see if everything else is cool until it arrives. Thanks.
think of your solenoid as a powerful magnetic switch.if it was me,id bridge the terminals with a suitable driver and carry on useing the bike until the new switch arrives.but thats me
 

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To add a wee mantra I often use

"Test dont guess"

In other words, dont buy stuff you dont need



First thing I'd do is leave the blown fuse be and get a meter set to continuity

A 1980 Custom is a CDI bike according to my manual and has a 6 way igntion switch connector

When you turn on the igntition, the power from the main fuse is supplied via the red wire to the black wire.

This in turn supplies the rest of the bikes electrical systems.



If you kneel down on the left of the bike you should see the 6 way connector

on the bottom of the switch up in front of the headstock.

The black wire is the bottom left one

This is the one you stick a probe in and first off, put the other to ground where

it sounds like you'll get unwanted continuity.



While you're there, check the cables haven't chafed against the headstock and worn away the

insulation, its been known for this to happen.

If it is that, just renew the insulation and yer good to go !



If it isnt the problem, the usual way to test is to disconnect one circuit at a time until

you dont get continuity and this gives you a pointer towards the short.



Easy on a Brit bike where nothing comes on unless its switched

but US models have lights on all the time I believe?

In that case you need to disconnect the feed to the lights or whip the fuse out

and add it to the debug process where you may find its a short in the lamp.



I wouldnt fit another main fuse until satisfied I'd found and fixed the short



HTH
 

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Discussion Starter · #7 ·
OK, so I had a short. I found with multimeter, thnak God! My Dad had just installed new mufflers on my bike and had tightened down one of the bolts for the new bracket right onto the brake light actuator wire. So, it was shorting there. So, I cleaned up my solenoid reassembled and everything is good to go now, fires right up again!! Thanks guys.
 

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If it reads 12v at the solenoid with the key out, I'd be kinda worried. I don't think it should be energized until you press the starter button. Reg is spot on. You have a circuit that is conducting electricity that should not be. somewhere after the main fuse, a hot (12v) wire is shorting to ground. this is drawing enough (30amps or more) to blow the main fuse disconnecting all power. There are some chafe spots to check in your harness like next to the tank. with battery disconnected, Connect any color wire other than green to a known ground on the frame through a continuity meter. If it reads zero ohms it is shorted. trouble shoot either from the switch to the battery or visa versa but not in the middle.



Just a guess but I think your ig switch has a short which is sending continious juice to the relay-solenoid even after you have released the starter button.
 

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OK, so I cleaned up contacts in solenoid and reassembled. Retested and with ignition "OFF" I am get 12.50 volts when touching mulitmeter terminals to opposite top terminals on solenoid. I shouldn't be getting anything right?
Sounds quite normal to me.

whats the fascination with the solenoid?

You have what sounds like a short to ground, you'd be better off chasing that

If the solenoid HD side went short, the bike would burst into flames

( well .... it wouldnt be pretty anway)

and if the solenoid switching side went short it would only blow the fuse when you pressed the starter



you get a short when you switch on the ignition right?
 

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Sounds quite normal to me.

whats the fascination with the solenoid?

You have what sounds like a short to ground, you'd be better off chasing that

If the solenoid HD side went short, the bike would burst into flames

( well .... it wouldnt be pretty anway)

and if the solenoid switching side went short it would only blow the fuse when you pressed the starter



you get a short when you switch on the ignition right?
LOL Reg... It's called "solenoid syndrome" .



It's related to "stator" disorder




Anyone ever use a screwdriver between battery terminals as fuse/welding rod ?



this is why we have the big fuse, Short a hot directly to ground without it and get the fire exstigusher for sho!
 
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