Tired of replacing headlights.

[Guest]

I finished replacing the RR with the one that's recommended on here before it became a problem and in Hope's that it would keep from blowing the low beam on the head light... last summer I lost 2 of the cheaper 7" silvana bulbs and finished the season with the highbeam. This time thinking the problem would be solved I got the brighter silvana bulb and at key on it seamed overall dimmer than the cheaper one. I went for a ride tonight and stopped and it blew the low beam again with 20 minutes on it. It never blows the high beam the headlight connector "looks" okay but haven't cleaned it. Could this be a problem with the new RR or start plugging through the harness? Also what's this about using relays for everything?

[Steve]

Before you keep guessing and shotgunning some parts, get some voltage measurements. You said you replaced the R/R with the one that is recommended here. Which one? Are you sure you got the right one?

I ask that because there are a LOT of eBay auctions that mention the R/R is "for ..." or "replaces ..." but are cheap Chinese copies that don't do the job properly. Let us know exactly what you got and where you got it.

It is also possible that you DO have the right R/R, but it's not quite installed properly. This can result in voltage spikes. Those spikes can take out headlights.

Relays can be wonderful items and do a great job, but simply throwing them into the mix is just tossing Band-Aids on a major wound. Again, some measurements with a voltmeter will tell you whether you have problems. Once you determine that you DO have a problem, just a little more measuring will tell you WHERE the problem is. Once you know where the problem is, you can determine what it's going to take to rectify it (pardon the pun). A relay can certainly bypass the problem, but the problem will still be there.

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[OldVet66]

The only time I have blown headlights is when I had a defective charging system and it was putting out too much voltage. Take Steve's advice and check out everything thoroughly and confirm that you do have a Series R/R. With a Series R/R I have never blown a headlight bulb, but I was never satisfied with the light output of halogen or Xenon. I have converted to a Cree LED system and am quite happy with it, but it does require a Series R/R so the reduction of wattage by half does not cause it to overcharge as it will with a Shunt type R/R.

[APmech]

Screenshot_20190501-081239_Chrome.jpg this is the RR I'll check voltages tonight.

[Brendan W]

Afaik that's a shunt unit.

[Rich82GS750TZ]

Afaik that's a shunt unit.

yep, a fake for sure. Not a real Shindengen SH775.

[Gorminrider]

Are these "sealed beams"? or actual bulbs you are replacing?

IMO generic Sealed beams are generally garbage nowadays and not suitable for motorcycles at all. They will fail exactly as you describe. (I have a few "hibeam only"kicking around... ) But, if you must use a sealed beam look for a special one made for motorcycles, pickups,farm equipment...the wattage will match the motorcycle manual's specs and the lifetime should be much longer.

[OldVet66]

Even if that is a high quality Shunt R/R, the original conditions still exist that caused your problem in the first place and it is doing it again. You need to go through all the connectors, switches, and grounds, clean everything up with DeoxIT and coat the connections with dielectric grease. Then find a SH-775. The conditions that cause bulbs to blow can also damage the stator so that should be inspected for dark discoloration and checked out also.

[Redman]

I finished replacing the RR .
....
.....I went for a ride tonight and stopped and it blew the low beam again with 20 minutes on it. ...........

Is difficult to troubleshoot electrical problems with your own senses, what you gonna use? Sight? Smell? Feel? Hearing?
You need a volt meter to determine if charging system is overcharging.
Something like upper 16volts or 17 volts will blow headlights and other bulbs, 18 or 19 will do it quicker.

Even if you have a good stock R/R, or other 5 wire unit, maybe it is not well grounded.
If you have a unit with the extra "sense" wire, maybe it is connected where the voltage is lower, so it cranks the output voltage even higher.

Any way, we are only surmizing a charging problem (overvoltage) because are blowing headlights.
Need a meter to verify this.

[APmech]

They are sealed beam headlights that I have been replacing and they don't go out going down the road. It either right at key on (which is were I think its happening because last night I think I noticed before started it) or right as the engine fires.

Redman
They're 40 year old bikes nothing is a new problem, I was hoping to have a starting point for tonight. So ya I listed symptoms to find that point or to have someone say yep that happened to me its "x."
The RR has a good ground, new wire right to battery.
When I test ran it to check if it was charging it was at 13.4ish idle and 14.5ish at 5-6k.

[OldVet66]

You have a lot of connections and switches that probably have a high contact resistance that lowers the voltage causing a higher current draw. The only way to fix that is to go through the entire harness and clean all contact points, switches, plugs, fuses and grounds. Those accumulated resistances will fool a Shunt R/R that is dependent on an expected load into all sorts of erratic behavior. Look for burnt bullet connectors because they will turn a dark color under the semi clear boots if they have been overheating and will be almost impossible to pull apart. Those will need replacement. You can also get replacement headlight reflectors that will take the standard H4 bulbs that twist in the base.

[APmech]

Are these "sealed beams"? or actual bulbs you are replacing?

IMO generic Sealed beams are generally garbage nowadays and not suitable for motorcycles at all. They will fail exactly as you describe. (I have a few "hibeam only"kicking around... ) But, if you must use a sealed beam look for a special one made for motorcycles, pickups,farm equipment...the wattage will match the motorcycle manual's specs and the lifetime should be much longer.

Where would you find those?

[Redman]

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.
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The RR has a good ground, new wire right to battery.
When I test ran it to check if it was charging it was at 13.4ish idle and 14.5ish at 5-6k.

Yah, a typical cause of burning out bulbs is some problem with the charging system causing a high voltage.

But now that you have measured the voltage, now we know that is not the cause of your problem.

I have no good next suspect.

PS: WHen you say "new" wire direct to battery, you dont mean just now, do you? After having this problem?

[fbody_mike]

Vibration can take out bulbs too, is the sealed beam units fitting snugly in the bucket? Rev the motor up to 4K and touch the lens, maybe it is really vibrating. Can you actually see a broken filament in the bulb, sometimes you can tell the difference between a burned filament that disintegrates vs. one that broke mechanically.

[Redman]

Now that we know is not high voltage - - - -
Other thought:
When you say burning out head light, do you mean "burnt" as in the glass has a dark haze and the filament measures open-infinite-NoContinuity with ohm meter? Or do you mean just that the light goes out?