I had to replace the ground wire going to my start relay (which keeps going bad), there are two start relays on the 99 Ultras, one under the front fairing and one under the seat.The stock wire size is 16 guage, I installed 10. Is there any danger in the ground wire being to large? The hot wires going to the same relay are also ten gauge. The smaller ground wire is consistant to every circuit under the fairing.

Can this create other issue's?

 

No - yer fine. Generally speakin', you kin run one wire size smaller ta ground/neutral than what's feedin' the circuit an' still have plenty of spare capacity. Makin' it bigger is NO problem - jest make sure that the connections are clean AND tight - that's usually the root cause of any problem.

 

Thanks TR, I was pretty comfortable with it as that's how we lookin high voltage (im in HVAC repair) but do not knowmuch about 12v automotive. Getting ready to go on a trip to Yuma thisweekend, don't want to have to do another roadsiderepair caused be my own doing

Any advice as to why I might be going through relay's?

On the same note, as I was redoing the plug I found one (or two) of the 3 red leads going to that relay is always hot, even with the igntion off (I did'nt check it with the kill switch in off position), anyway should theyhave constant power? Maybe that's whats killing the relays?

 

Generally speakin', one side of a relay is always "hot" - the purpose of the relay is to act as an on/off "switch" for that power. I'd be looking for something causing resistance in the wire - like a bad ground point or burnt/corroded contacts/connectors. The wire you just replaced could well have been the root cause in itself.

Think about it - the same stuff you see in HVAC electrical comes into play with 12V - it's just more pronounced owing to the lower voltage. A dirty connection will create resistance, creating heat, creating melting/premature failure....

 

Think about it - the same stuff you see in HVAC electrical comes into play with 12V - it's just more pronounced owing to the lower voltage. A dirty connection will create resistance, creating heat, creating melting/premature failure....
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Yeah I know It's just that I've been chasing this little demon for awhile and have torn that bike apart 3 times looking for the root cause. Sometimes I can go thousands of miles without failure and sometimes just a few hundred. Although I had been using AutoZone relays as all the numbers matched up, however I've been told that Harley uses a diode in thiers now...so maybe they are better (sure do cost more), we'll see if they last longer.

I installed theHogTunes amp 6 months ago (I think we talked about it), it's on a seperate circuit direct to the battery, except for the wake up circuit which goes to the lighter so "it should not matter) but it does seem to go through the relays much faster than before. Coincidental ?