Arcs and Sparks!

[joblandin]

So my girlfriend's dad drops this 66 305 at her house so she can learn to ride. Problem is it doesn't run and it's on me to get it fixed (We've all been there). This is the first of many posts for me I'm sure, so any help would be greatly appreciated.

First thing I figured was a new battery, so I went to the local Honda shop, picked it up and when I tried to install said battery, I get lots of arcs and sparks. I'm figuring there's a ground somewhere (it got dark before I could meter everything out). I took the inline-fuse out of the wiring and it still arcs.

Can anyone point me in a direction to start? Looking at an old wiring diagram, it appears that the power runs from the battery to the ignition switch, could I have a ground in there?

Thanks,

John

[e3steve]

NOTE: always disconnect & re-connect the negative cable at the chassis, not the battery post; think of the chassis grounding bolt as a switch. Sparks at the battery post could cause any stray hydrogen gas (given off by the cells during charging & discharging) to explode. At best that's a new battery, at worst you could lose your sight if you're close!

Take the problem stage-by-stage:
1. are you connecting the batt in the correct polarity (ie: neg to chassis)?
2. is the ignition switch in the off position?
If 'yes' to both, it sounds like
a) a short-circuit to ground within the ignition switch
b) a short-circuit to ground within the harness or a device connected to same
c) a short-circuit to ground within the starter solenoid or circuit

3. is the starter trying to engage?
If 'yes', then the starter solenoid is stuck in the 'closed' or 'start' position

Leave off the heavy wire from the pos batt terminal, that takes the starter circuit out of the equation for now.

Put the 15A fuse in place.

Use a working 12V lamp of at least 60 Watts (the hi-beam filament a car headlamp bulb is good for this), and make up a test lamp with about 2ft of cable (14AWG or larger) with a couple of croc-clips on the ends; connect this 'test-lamp' in place of the negative cable (ie: 1 clip to chassis, the other to battery neg post - remember: connect to the chassis LAST). If there's a short in the wiring somewhere, then the lamp will burn full-brightness. Leave the lamp in place and work around the wiring, disconnecting items until the lamp goes out (or dim).

Ignition switch wiring & terminals should be as follows:
Term BA, battery, red
Term HL, headlamp switch, green
Term TL, parking lights, white
Term IG, (ignition system) & key-on circuit, (unspecified) & light green/red
Term CH, charging from rectifier (celenium diode pack) white/red

4. start at the ignition switch, disconnecting the 15A fused feed first - just take out the fuse

Lamp still bright? Put the fuse back in and disconnect the wires from the ignition switch terminals one at a time; if the test-lamp goes out on one of them, that's the problem circuit.

Email me with your findings. Next stages will follow....

Regards,

Steve Edwards

[joblandin]

Steve,

Thanks for the tips. I'm on business travel right now, but will attempt your suggestions when I get home and post the results!

Much appreciated,

John

[e3steve]

Cool John. Incidentally, what the lamp is doing is acting as a self-resetting fuse, absorbing the current in place of the short cct. If the lamp glows full brightness, then your problem is of a high-current, low-resistance nature (starter motor / relay [solenoid] or a dead-short); if it glows dimly, then it's something on the bike that's consuming some current.

It's a good idea to have another lamp of lower wattage (a car winker lamp, 21Watt) with cables and croc clips to hand as well, for smaller wiring conductor size traces.

Also, start off with a fully charged battery.

Rgds

[e3steve]

Just re-read your original post, John. You don't say if it's a C(A) or CB(P/YP); their wiring differs. If it's a Dream (C or CA) then this problem could be the rectifier short circuited, as that's connected directly to the batt pos post; if it's a Superhawk (CB, CP or CYP), the rectifier isn't in cct until the ign is on, so my original method of diagnosis still stands.

I'll shut up now!

Laterz.

[joblandin]

I believe it's Dream, not a Superhawk.

[e3steve]

If it's a Dream, John, then the kichstart is traditional and the headlamp rectangular; the instrument cluster isn't (a cluster, I mean - it's just a speedo). If it's a Superhawk, it'll kickstart forwards, have a round headlamp, a speedo/tacho cluster and the footrests are adjustable rear-sets. The ign keyswitch on a CB (Superhawk) is in the upper part of the l/h side panel, whereas on the C (Dream) it's in the l/h/s of the headlamp.