1984 Honda Nighthawk | GTAMotorcycle.com

1984 Honda Nighthawk

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Mongo

Member
here's one.. bike turns on.. lights up.. but hit the starter switch.. lights all dim.. doesn't turn over.. New battery.. New cables.. bad ground somewhere I can't find I think.. suggestions?

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What's the voltage at the battery. Is the battery brand new? When was the last time the bike started, if last year did you charge the battery? Need more info.
 
Can you turn it over by hand (If you have a center stand, put it on center stand with rear wheel in the air, bike in low gear, ignition off and turn the wheel to spin the motor). If you can turn it over a few times that way, can you bump start it?

If the lights are dimming lots of current is going somewhere, carefully inspect the wires in the starting circuit. Normally a bad ground manifests as a complete black out when you hit the starter.

If you have a multi-meter, what is the battery voltage at rest? What is the voltage when you press the starter?

Why were the battery and cables replaced?
 
battery is at 12.52 volts.. tire will spin and I can hear compression.. so I imagine it will bump start..it does go totally black when I hit the starter switch.. battery was new last year...

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Mongo said:
battery is at 12.52 volts.. tire will spin and I can hear compression.. so I imagine it will bump start..it does go totally black when I hit the starter switch.. battery was new last year...
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Haul the battery out and take it somewhere to have it properly load tested.
There's nothing inherently faulty with the design of that bike, other than its now 30+ years old.
 
12.52 volts is low, good enough to light the lights but not turn the engine. Do you have a charger, if so then charge the battery. The nighthawks don't have the best charging system if your riding around town so I suggest after you get it going that you buy a motorcycle float charger. When you put new cables on, did you clean the connections?
 
Mongo said:
it does go totally black when I hit the starter switch.
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Totally black puts me onto the bad ground path. Check the ground connection at the battery and from the battery to the frame. Did you clean off corrosion/paint at the frame connection when you replaced the cables?
 
On my 84 nighthawk 450, the ignition switch went wonky. It was a long time ago so I don't remember the details, but in general terms, there are a number of contacts in the switch (they look like staples) that are supposed to float but mine were sticking and didn't always contact properly. I bent a fork like the rock on hand sign and jammed it in the back of the switch to fix the problem when it would act up.

I still think this is a ground problem but always keep an open mind for other possibilities.

EDIT:
Has it ever started since being rewired? Is there any chance the wiring got connected improperly (eg cable from ground of battery to solenoid instead of frame?)

Do you have a vehicle and/or other battery that could be used to jump the bike to try to narrow it down to wiring or battery problems?
 
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Mongo, where are you located? (Closest main intersection and town/city). Maybe someone off this forum lives or works near you and could drop by and take a look?


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I would have to go with this. Sounds like power is going to ground when you hit the starter button. I would guess the starter and/or relay is bad/shorting to ground. as another poster mentioned you could use a screwdriver across the posts of the solenoid (relay) to check if its working. use an old screwdriver and expect some sparking off the terminals. what your doing is checking to see if the relay (switch) is malfunctioning. by going across the terminals you are jumping the relay switch internal parts and making a direct connection to the starter..your screwdriver will be the switch.

edit - but im going to guess its the starter, for whatever thats worth lol
 
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Try jumper cables from your car battery. Positive to battery positive. Negative cable to your bike chassis. If that starts, then try it again with the negative moved to your battery negative.
 
empty said:
Try jumper cables from your car battery. Positive to battery positive. Negative cable to your bike chassis. If that starts, then try it again with the negative moved to your battery negative.
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I like this. This should indicate if there is a grounding problem? care to explain?
 
boyoboy said:
I would have to go with this. Sounds like power is going to ground when you hit the starter button. I would guess the starter and/or relay is bad/shorting to ground. as another poster mentioned you could use a screwdriver across the posts of the solenoid (relay) to check if its working. use an old screwdriver and expect some sparking off the terminals. what your doing is checking to see if the relay (switch) is malfunctioning. by going across the terminals you are jumping the relay switch internal parts and making a direct connection to the starter..your screwdriver will be the switch.

EDIT - but im going to guess its the starter, for whatever thats worth lol
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2ND EDIT - if when jumping the relay/solenoid switch you find the starter does not crank, and the screwdriver is arcing on the terminals (has power), I would say the starter is facked and going to ground internally. the relay itself may overheat/malfunction if repeated attempts of thumbing the starter button have occured - and you may find yourself replacing the starter and solenoid switch.

let us know how things progress. you should try this with your new battery trickle charged to ~ 13v or more first.. best luck.
 
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^

yup, only thing I'd add, is that a DC electric motor is a (controlled) short circuit
very low resistance until it starts to turn
so if it does not turn (because it's shot or the engine won't turn) current flow will remain high and dim the lights
 
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