[Motorcycle Electrical Problem] Any motorcycle electrical type folks here?

[DaveTN]

I know this is a long shot for a gun forum, but I’m desperate.

I’m trying to get my bike ready for a trip next weekend. I started it for the first time this year last weekend and rode it about 50 miles. The next day I was going to ride it to Clarksville… would not start. It was kicking the 50 amp main breaker as soon as I turned on the ignition, even before I tried to start it.

I found that a relay in the fairing was the problem. When I unplugged it I could turn the ignition on without blowing the main breaker. The Harley store was closed so I replaced it was an automotive relay they said was the same. (BWD R681 from O’Rileys).

The bike started fine and I took it for a ride. Stopped back at home went to start the bike and it wouldn’t start. I heard the main fuse (next to the battery) kick out before I hit the starter. Only this time I heard a clicking noise in the fairing.

I took the headlights out of the fairing and it was this relay clicking before the main fuse kicked out. It was very hot to the touch when I pulled it.

According to a picture in my service manual showing the two relays behind it, the one on the left is the brake light relay and the one on the right is the starter rely. It doesn’t show this relay. The two other relays are mounted to the fairing; this relay was just tie wrapped to the cable going to the other two relays. I don’t know what gage wire it is, but the three red wires that this relay plugs into are pretty heavy compared to everything else around them, it has one smaller black wire.

I’m trying to get this fixed for a trip next weekend and of course the Harley shop isn’t open to get a Harley relay tomorrow.
But I don’t know that a new relay will fix the problem????

1995 Harley Ultra TourGlide FLTCU

[frankmako]

ground wire problem?  i have been chasing electric problems on my 1987 flhs since 1988.  sometimes you will not fix the problem.  i just found a work around to keep the bike on the road.  check the starter relay.  my was wired in backwards.  gave me problems with my head light going dim when i hit the brakes.  hd relays are auto relays and the auto relays will work.   there is a ground wire block somewhere in the front faring where many grounds wires go to it.  when i start having a electric problem i check it first.  most time i find a wire that has come off/loose.  also check your ground strap from the motor to the frame.  take it off any put back on.  but i could be wrong about a ground problem.  but on my bike it all way been where i go to first. 

[DaveTN]

Thanks Frank I’m in the process of checking all the wiring. I’m no electrician, but just can’t figure out what could be drawing enough to kick a 50 amp breaker when I plug that relay in. I even turned out the lights in the garage and tried it, thinking if I had a bare wire somewhere touching something I should be able to see a 50 amp short; but no luck, just this relay clicking.

[TerryW]

Dave, cut the blue wire! No the RED WIRE!!  

 

Just kidding....

 

If you are interested I know a guy near Dickson that has worked at most of the motorcycle shops in Nashville in the past 30-40 years.  Retired, now he works out of his house and I have found him to be very sharp, honest and reasonable in price.   If you are interested I will see if I can find his number.  I know for sure I can give you radar vectors to his place.   PM if you are interested

[Sam1]

Are those all new relays or did you just replace the one that was suspected to be bad?

 

<edit> after looking at the parts fiche for that I see what you mean now, that relay with the 12 gauge wires says it's supposed to be on a 4 way connector to a terminal, and not a relay.

 

I would get on the Harley forums somewhere and ask clarification on that because I'm not familiar enough with those to know what the deal is with it.  Sometimes on the Honda's the wiring can be updated from a factory change and they never do a good job of distributing the publication changes.

Edited April 27, 2014 by Sam1

[Howler]

Before you go any further make sure the relay is the same as the OEM. Look on the side of the relays and see if there is a wiring diagram. Make sure it is exactly the same. Don't take the parts guys word for it.

 

 It looks like a regular four wire relay. Two wires will supply power, one will be a ground, the other will be the wire that carries the voltage when the contact of the relay closes. Trusting that it is the correct one, do this. Unplug the relay. Make sure (with the key on) that you have a full 12v on two of the wires. One of the hot wires will be from the battery and one will come from the ignition switch.  With the key now off, use an ohm meter to check resistance between the relay ground wire and ground. The resistance shouldn't be very much. A few ohms at most. No K ohms or M ohms. It's been my experience that when a relay is clicking fast that either the ground for the relay is bad or there isn't enough voltage to keep the relay contacts closed or the relay is bad.  

 

I had a vehicle the other day doing the same thing. I found that the ground wire (where it was bolted to the body from the factory) was loose. It was causing an intermittent starting problem on a car that was 9 years old.

[bersaguy]

I'm by no means a bike mechanic but worked on cars 35 years and if bikes are similar in wiring operations there has to be a 40-60 amp power source relay some place that powers up almost everything. Most cars had accessory relay that served that purpose. Sounds like you have a main power source relay issue because it reacts soon as you turn the key on just like the one in a car does. It feeds power to everything required to operate any and all accessories and will actually have an effect on the starting system. If you don't have any luck and you can trailer the bike to Gallatin I have a buddy that has 3 Harley's and he works on his own and does all his own repairs after warranty is out on them. I can ask him for his help on this if need be. Let me know in a PM if you want me to talk to him about helping................ :up: :up:

[TripleDigitRide]

I'm not going to be much help, but I wanted to let you know that I feel your pain. I had a similar issue with my Vulcan Nomad. I finally gave up and took it to Conrad at TNT Performance Dyno. That was money well spent. One of the best bike mechanic/tuners in the Middle Tennessee area.

[frankmako]

most hd relays are the same.  you can pull/change them around to see if one is bad.  start pulling fuses.  one at a time to see if that system is the problem.  it sounds it is on the starting side.  pull fuses that have nothing to do with the starting first.  pull fuse, it problem is still there, leave fuse out and pull another.  keep going until you find the system that is causing the problem.  do the same with the relays.  but i would still look for a grounding problem. 

[DaveTN]

Okay I think we found the problem. The back of the instrument cluster had cut through a wire and was shorting out.

The trouble finding the problem was that the wiring that was connected to a relay was not in any of the electrical diagrams in my service manual. The parts guy at Harley thinks it was added as part of an ignition switch recall that was done many years ago.

My issue now is that the wire that was shorting showed 0 volts with the ignition on and common with ground with the switch off. The guys on the Harley forum thought that it should have voltage. With the relay plugged into the harness it would kick the main fuse and the relay and wires were so hot you couldn’t hold them. When I found the short and fixed it seemed to be fine, ignition on it didn’t kick the fuse, nothing was hot, and bike would start.

The mystery is that with the ignition off that wire still shows common to ground. It runs from the relay in the faring, splits off under the instrument cluster and goes down and connects into a fuse panel in a terminal that doesn’t have a fuse in it.

I’m not electrician so I would like to know if that wire and relay can be 12 volts with the ignition on and common with ground with it off?

[peejman]

If it was part of an ignition switch recall, they must have published a new wiring diagram for the mechanics to use when implementing the fix.  Make the dealer find it.

 

I'm not an electrician, but I can read a wiring diagram and usually figure things out.  Without one, it's really hard to diagnose.

Edited April 28, 2014 by peejman

[tnguy]

I think it's not unusual to ground some things with the ignition off. I've seen several bikes where the "off" was achieved by grounding the wire to the coil. (Thus allowing us to bump start a friend's bike by disconnecting a connector in the fairing).

[Sam1]

If it was part of an ignition switch recall, they must have published a new wiring diagram for the mechanics to use when implementing the fix.  Make the dealer find it.

 

I'm not an electrician, but I can read a wiring diagram and usually figure things out.  Without one, it's really hard to diagnose.

 

They won't always publish changes, and keeping fiche up to date or service manuals is a nightmare. From personal experience, the companies will normally put the changes in the newly released schematics, but not any inserts for old ones unless they go to a dealer that pays for updates.

[No_0ne]

 

I’m not electrician so I would like to know if that wire and relay can be 12 volts with the ignition on and common with ground with it off?

It depends on the internal connections of the relay in question, but yes, it's possible to have one "pole" of a relay set up as a "double throw" to make 2 different connections depending on the position of the contacts.  I've wired reversing switches on electric winches using a DPDT (double pole double throw) relay which does that to reverse the current through the motor.

Edited April 29, 2014 by No_0ne

[peejman]

They won't always publish changes, and keeping fiche up to date or service manuals is a nightmare. From personal experience, the companies will normally put the changes in the newly released schematics, but not any inserts for old ones unless they go to a dealer that pays for updates.

 

 

I understand and agree.  But being a recall, I would hope that all the relevant documentation would be available from the OEM.  One might even think that there would be a system in place to flag any recall eligible bike that came in to a dealer for service to verify that recall had been implemented.  But maybe my expectations are too high. 

[No_0ne]

Deleted due to senility.

Edited April 29, 2014 by No_0ne