82 GS750 electrical oddity.. need help

[Super]

So here's my problem. When my headlight is plugged into the wiring harness, my starter won't work. You can hear the solenoid clicking as if the ground is bad. When I unplug the headlight, the starter turns over just fine like it should. And yes, I am holding in the clutch in when I try to start her up. I didn't think the headlight had anything to do with the starter working properly..?.. I know the battery is good, it's only a few months old and just in case, I put it on the charger and it was fully charged in about 10 minutes and switched over to float charging. I know the starter button is good as it had broken recently and I had put a new one in just before I put the bike up for the winter. And it turned over just fine after I did that.

I've never heard of this before and I'm not sure where to start. Could it be a ground wire somewhere that's not good? But I don't see where the headlight comes into play. I first thought it was the headlight taking too much power from the battery when it's on while trying to start but it's pretty new and reads 13V after the 10 minute charge.

Any help would be appreciated.

[Super]

Ok, here's an update. Plugged in my headlight from my 78 GS550. It turned over the first time with that headlight plugged into the headlight socket and the headlight had power. But it became intermittent on following attempts. Guess it's not the headlight so I'll be trying to track down any problems with the ground wires coming out of the headlight socket.

[Steve]

You have some jumper cables? If so, connect them to your car, but have the car's engine NOT RUNNING.

Try starting again, with the headlight installed. If it starts well, you have a bad battery.

Just because it shows "full charge" quickly does not mean that it's a good battery. Also, reading 13 volts right after a charge is meaningless. If you want a better idea of battery voltage, connect your meter (observe your 13 volts), turn the key ON (with headlight installed). Wait about a minute, turn the key OFF. What is the voltage now? A good battery will still show over 12.5 volts.

One more clue to be invesitgated, ... what is the battery voltage while you are cranking the engine? If it is below 11, get a new battery.

.

[posplayr]

If you did a quick test, the firt two steps test the battery.
no jumper cables needed but you do need at volt meter.

[Super]

Ok guys. I'll double check the battery. It sounds like that may be the issue but I was pretty sure the battery was good. Thanks and I'll let you know what I find out.

It may be a while though as I'm also in the middle of something else... changing the oil, etc. on my Goldwing.

Thanks again.

[Steve]

... I'm also in the middle of something else... changing the oil, etc. on my Goldwing.

That's easy enough and will handle of its needs for the year.

Which Wing do you have?

[Super]

I picked up a 1984 Interstate last summer. Only 56K miles and documentation to prove it came with it. It had also just had the timing chain done and all the needed upkeep for a bike of this year. I was real happy to get it. Nice burgundy color too. I basically got it for my wife. I was shamed into NOT putting a back rest on the 82 GS750E by my two sons. So it only seemed the right thing to do for my wife to comfortably enjoy our rides together.

[Super]

Update: I hooked up the battery from my Goldwing, that I know is a good battery, and got the same results. When the headlight is unplugged from the socket, it turns over just fine. If the headlight is plugged into the headlight socket, the starter solenoid just makes the click sound.

Guess I'll be trying to run down a short or bad wire somewhere. If anyone has any ideas of what direction I should look at first, let me know. I think I'm going to work on the ground wire coming out of the socket first. It goes into a piece of shrink wrap as a single wire and comes out the end as 2 wires. These 2 wires go into a connector. Maybe the soldering of where it goes from one wire into 2 wires is compromised under the shrink wrap.

Any ideas would help. Thanks everyone

[posplayr]

Update: I hooked up the battery from my Goldwing, that I know is a good battery, and got the same results. When the headlight is unplugged from the socket, it turns over just fine. If the headlight is plugged into the headlight socket, the starter solenoid just makes the click sound.

Guess I'll be trying to run down a short or bad wire somewhere. If anyone has any ideas of what direction I should look at first, let me know. I think I'm going to work on the ground wire coming out of the socket first. It goes into a piece of shrink wrap as a single wire and comes out the end as 2 wires. These 2 wires go into a connector. Maybe the soldering of where it goes from one wire into 2 wires is compromised under the shrink wrap.

Any ideas would help. Thanks everyone

You are now poised to learn why that test is not conclusive and basically can leave you uncertain of anything. The test as described (by Steve) could lead you to believe that you have a bad battery even though it might just be bad connections or cables. At this point you don't know do you?

Do the Quick test and it certainly quicker than all this screwing around.

With the Quick test, you need to be able to pull the battery down to about 12.2V with the 10 amp load. It is going to be hard to read 12.0-12.2V on the volt meter and have your headlamp on without having a good battery and good connections.

If the voltage doesn't drop that much and the lights are not very bright then you know it is bad connections.

If the battery drops below 12.0 and you have dim lights then you know it is bad battery.

The main reason the previous test is poor is that it is changing too much of the setup (not using all of your same cable)and checking a good battery to confirm that your old battery is bad; where is the logic in that? Only if the old battery is bad is the test conclusive. There are many ways that bad cables and bad connections could make you think you have a bad battery.

The only way to test a battery is to put a load on it.

[Super]

Ok, I hear you. I will do the Quick Test. I highly value your knowledge and all of your input on this site. So I guess what your suggesting is to start it up with the headlight unplugged (the only way I can get it to start), get it running and then plug the headlight back in to do the volt meter test at idle, 2500 rpms and 5000 rpms?

I guess what's really throwing me off is the darn headlight being involved in this. I've never seen anyone post a starting problem that involved the headlight. So I'm guessing the headlight is drawing too much power from the battery while I'm trying to start it up?

Thanks posplayer for the help. I will do this test tomorrow as I'm done for the day. Too beat to go out to the garage again tonight.

[posplayr]

To test the battery, you just stab the center posts of the battery with the VOM probes; and turn the key to the ON position (DO NOT START). See how far it draws the battery down (STEPS 1 and 2 of Quick Test). If you disconnect the headlamp then it will draw less and not pull down about 1/2 as far.

[Super]

Roger that! Thanks again.

[Super]

Update: Took my battery down to Advance and had them test it since I was going there anyway. It tested as needing replaced. Bought a brand new battery. Put it in, hit the start button, it turned the starter. On the second and subsequent tries, the solenoid just clicked. So I know it's not the battery.

Guess I'll check that ground wire coming out of the headlight socket and go from there.

Any advice/help would be appreciated.

[posplayr]

Update: Took my battery down to Advance and had them test it since I was going there anyway. It tested as needing replaced. Bought a brand new battery. Put it in, hit the start button, it turned the starter. On the second and subsequent tries, the solenoid just clicked. So I know it's not the battery.

Guess I'll check that ground wire coming out of the headlight socket and go from there.

Any advice/help would be appreciated.

here is a suggestion, do the Quick Test. It will tell you if you have dirty connections...................

[Super]

Update: I opened up the ground wire in the headlight socket and double checked it. It looked good. Then decided to double check the ground wire at the starter solenoid. The PO had a different looking ground wire set up than I'm used to. Moved them around some, didn't help and put it back like it was. All of a sudden it started working right. Now with the headlight connected and working, it starts every time. I'm guessing now that the solenoid ground wire was dirty and cleaning it up was the answer.


However, I did do the quick test, as you've mentioned several times. Since it was apart and running with a new battery, now was the time. It was a good thing too as it seems that my R/R is bad. When I had it running at 5K rpms, the voltage just continued to rise...14.5 ...15 ...15.5 ...16 .... 16.5... I stopped there. So I'll be looking for a new R/R now.

Thanks Posplayer for being so insistent.

I bought this bike from another person and pretty quickly gave it to one of my sons. I just got it back in time to put it up for the winter so I haven't had it long myself. It ran perfectly the whole time my son had it but now that it's back with me, I'll have some catching up to do as far as checking everything out.

Thanks everyone for your input. It's appreciated.