[DallanC]

So my pride and joy, a 400 Foreman that I bought brand new many years ago developed a perplexing electrical issue today.

We went up on probably the last ice fishing trip of the year. It was around 28F when we arrived at the lake. I went to start the old girl and she started turning over kindof slow... not uncommon on a really cold day and then I heard a pop/click and there was no power... No indicator lights, No headlight, no "click" from the starter. I have a winch wired directly to the battery. Clicked the spool out and then spool in, it immediately cycled the winch. Ok so its not the battery. I checked the fuse box, pulled each and visually saw all were good. I wasnt sure at the time if there was a master fuse so I didnt know to check that. I tried jumping across the solenoid with a wrench, absolutely nothing.

Depressed at being 3.5 hours from home with a dead machine (my wife and sons foremans were happily putting next to mine warming up). I decided to try pull starting it, knowing Hondas dont need battery power to generate spark... one yank and it coughed, second yank and she lit right up. All indicator lights were flickering at the engine RPM rate as happens when running off the stator only. Speedo was pegged at max, again an indicator of not enough voltage. As we were already up at the lake, we went fishing and I just pulled started it as needed.

We got home just a short time ago, one of the first things I did even before unloading the truck was hooking up my multi-meter to the battery. It was 12.8v. I tested ground to the starter solenoid positive feed, again 12.8. I tried testing voltage on the other side of the solenoid and pressing the start button... it was weird, sometimes it registered floating voltage levels, other times nada. I'm thinking that may be going bad, but I'm still thinking there is something wrong elsewhere to cause the indicator lights and displays to not have voltage. I kept poking around with the tester and suddenly my son goes "Hey the neutral light is on" what the... ??? Sure enough, head light too. I tried start, one click out of the solenoid and everything is off again. Grrr...

Its late here as I write this... and I'm tired. I disconnected all battery wiring incase there is a draw somewhere. I've been looking at the manual wiring diagram to see how to diagnose this. The machine runs, runs great! Its just lost all electrical to the main power circuit.

Question: The main positive wire to the solenoid, there are 2 (10ga?) red wires that run... somewhere? What are these wires and what do they power?

Tomorrow I will did alot deeper into this... its really behaving like a corroded master fuse. Some voltage occasionally allowed through... but definitely not enough to run the solenoid. I'll also do some wire "wiggling" to see if the indicator lights come on indicating a continuity issue on a plug or where ever.

-DallanC

 

[Here 2 help]

Check the battery ground lead where it attaches to the battery and the other end where it attaches to the frame or engine. whether the ground attaches to the frame or engine, a loss of ground (indicated by the sound of an arc) between the engine and frame might be the problem. On some units there is also a ground wire from the frame to the engine that may need to be checked. A ground link between the engine and frame is mandatory on rubber mounted engines.

 

[DallanC]

Holy crap... I've worked on some crazy electrical issues over the years, usually really good at figuring stuff out, but this was bonkers. Apparently I was getting voltage to some circuits but no amperage, no voltage to others... fluctuating voltages at times. Very odd.

I cleaned all the connectors, the battery terminals, reattached everything with dialectic grease and suddenly all the indicator lights were blazing bright. I hit the starter and fired right up in a fraction of a second. Crazy. Thinking it over in retrospect, I was changing where I was touching my ground lead on my multimeter. At times the nut on the top of the battery, others the lead post itself.

Anywho apparently it was either ground or positive terminals causing the issue. Oddly the winch worked 100% of the time through this, even though its connectors were on top of the honda battery connectors. Even stranger was that it was turning over then stopped when the original issue cropped up.

Maybe it still has a random issue somewhere, I'll keep an eye on it but for now, the battery cables seems to have been the culprit. Love to hear that machine purr.

As always, many thanks for the help and suggestions.

-DallanC

 

[Mr. NeverPlea]

Never hurts to add an extra ground to engine-frame-batt. I do even on my street cars.
One occasion in the past, I saw a build up of a chemical, like armour all or something similar sprayed on a batt that conducted 3.7 volts. I only found it after a sweaty belly rubbed a fender while holding the PLASTIC handle. Post to case side, 3.7 volts @ 12.3.

The arc you described sounds characteristically like a ground issue. I keep wires with alligator clips around for adding test circuits. Going around is faster than going through. For diagnostics.