1974 CL450 electrical issue - new member, first post

[Heywood]

Hi there

I picked this up at the end of last summer, it had been in dry storage since 1982. They did everything right when they put it away except for 1 thing, they took the plugs out. Though it's in great shape I guess it dried out or humidity got in there or whatever but it's locked up. This is my first bike but I used to be into old British cars so I know my way around an engine.

Since it's spring I bought a new battery, added the acid and let it trickle charge overnight, this morning it was ready to use. Normally pos (red) goes to pos & neg to neg, pretty straight forward. I connect the battery and right away I notice a wisp of smoke so i disconnect. I consult the factory manual that I bought, it looks like i'm going everything correct. I try it again & still smoke.

Remembering way back to my brit car days I recall cars with magnetos you would reverse the polarity & ground the positive. I try this just once, no smoke, lights turn on, horn works, starter will spin etc

But something just doesn't feel right about reversing it on a 1974 bike which the manual diagrams all show negative being grounded

Does anyone have any insight ? I'd like to square away the electrical before I get cracking on unlocking the engine.

Thanks for your patience from a bike n00b

Regards

 

[Sonreir]

Negative is definitely ground on the Hondas. At least the 70's one. There may have been a point in the (pre)60's where it was positive ground, but I can't think of any instances.

Just for additional info: Green is ground and red is positive. Black is also positive, so make sure you're using the correct connections.

 

[DrJ]

Just for additional info: Green is ground and red is positive. Black is also positive, so make sure you're using the correct connections.

Just to clarify, red is the positive lead directly to and from the battery, it's always live. Black is switched positive or the power lead, it's only live when ignition is switched to ON position.

 

[Heywood]

I've only got red & black and the black I already traced and verified it's grounded to the frame and there are 2 red wires. 1 is a thinner wire and goes to a small fuse and the other goes directly to the starter solenoid. Everything on there nooks original, nothing looks fugazy. I know that when I hooked it up initially and got the wisp of smoke i didn't even have the key in the ignition switch (but i didn't look first to see which of the 3 positions it already was in)

 

[Hoosier Daddy]

First off, welcome to DTT! Some of the smartest motocycle SOB's on the planet seem to hang out here... too bad I'm not one of them

Since it's spring I bought a new battery, added the acid and let it trickle charge overnight, this morning it was ready to use. Normally pos (red) goes to pos & neg to neg, pretty straight forward. I connect the battery and right away I notice a wisp of smoke so i disconnect. I consult the factory manual that I bought, it looks like i'm going everything correct. I try it again & still smoke.

Remembering way back to my brit car days I recall cars with magnetos you would reverse the polarity & ground the positive. I try this just once, no smoke, lights turn on, horn works, starter will spin etc

It's early AM here so I am not 100% yet but this one peaked my intrest... at the moment I am scratchin my head.
So You verified the positive cable goes to the starter relay and the negative cable goes to the frame. This is correct, as stated these bikes are NOT positive ground like your British cars were.
When you connected the battery and saw smoke, where did it come from? Naturally this is not a good thing but ESPECIALLY with the ignition off.
Then you connected it backwards, (battery positive terminal to ground cable to frame) turned on the ignition and have lights, horn, (ok I'll buy that) AND the starter turns?! A DC motor will turn backwards if the polarity is reversed. Did it crank the engine over or just free-wheel? The starter clutch would not engauge if the starter motor was rotating backwards and just "whirr", not crank the engine.
If it cranked the engine and you a SURE of the connections, the only thing I can think of is when you intitially charged the new battery after filling the acid you had your charger terminals swapped and now your battery reversed polarity.
Can't say I have ever heard of that one but I suppose starting with a new dry battery it is posible.
Take a meter, (not a test light) and with the red lead on the positive terminal, black on negative, verify it is not showing as "-12v".
Man, that is all I can think of at the moment... I'm probably gonna stew on this one all day now.(Thanks a lot! ;D ) Good luck and keep us posted on you findings.

 

[Heywood]

Thanks for all the assistance so far.

The smoke

Just to the rear of the battery holder between the small space where the solenoid and fender meet there is a quik-connect plug that i suppose is feeding the tail light & turn signals. From 1 wire only there is a wisp of smoke as fine as a blonds hair with the usual insulation smell. I intend to disconnect that this morning & try again to see what happens. That cruel mistress mother nature gave me a 70degree day when i first started fiddling around with this but today she's no higher then 35 so I'll bring the heater with me.

The starter did just whir around and not engage so that explains to me why it spun when the poles were reversed. The battery is brand new as well as the charger. I don't have it at hand to supply the brand name but the cable to the battery dead ends in a special plug that you can only plug the adapter wires into one way, insuring red = red & black = black. It has 2 adapter cables, 1 terminates in the familiar spring jaws found on most jumper cables and the other terminates with leads (red & black) just like the stock ones that attach the bikes cables to it.
I filled it with acid, let the bubbles dissipate and liquid settle, waited 2 hours, filled where needed to the fill line then using the ring terminated cable attached those to the battery and began charging. The charger also has a fail-safe in it that will indicate if polarity is reversed & won't charge the battery.


I'll give it a try again today, disconnect that quik-connect plug and hook it up properly and see what happens. I checked my old telco tools but no meter so if id doesn't work this time I'll go buy one. Any recommendations for what brand ?