1980 atc 110 headlight switch causes engine to stall

[1980atc_110]

I have a 1980 atc 110 I just brought back to life after who know's how long. She fires up, runs and idles wonderfully, however when I turn on the headlight switch to the lo or high position it kills the engine. The light will come on but I can't keep the motor running, even at an elevated idle. FWIW this is a 1980 model with the headlight switch on top of the headlight bucket. Thanks in advance.

[coolpool]

If that switch works the same way as a US90 switch, then it sounds as if there are some wires crossed in the bucket. The "0" position is actually the engine kill switch and the "I" is run with no light and the "II" is run with light. The handlebar switch is an "emergency kill switch". Do you have a manual that shows the wiring diagram? I don't believe that machine has a high and low beam.

[Pinebarrensbrew]

mabey someone tried to run the light into the killswitch wiring. i brought that up to my buddy and he said it could kill the bike, not enough voltage or somthing along those lines. my 110 has wire coming from the headlight switch but no wires coming from the power source for the lights, i was trying to find an easy way asround running all new wires, but i guess if ya cant do it right the first time dont do it at all. that seems to be the recurring motto in and of my fixes.

[kb0nly]

Your going to have to do some wire tracing just to rule it out... The 80 with the round headlight has a off/lo/high switch on it that only controls the lighting, that i know, i have worked on a few of them. There is a good chance your going to have to open the motor and check the ground at the stator. There is two coils on the stator plate, one is the ignition source coil and has a Black wire from it and the other is the lighting coil/alternator and has a Yellow wire from it. They both have a wire that comes off the other end of the coil and grounds to the plate. If that ground goes bad and you turn on the lightswitch the ground for the light shorts the ignition coil, it puts the coils in series instead of in parallel. So when you turn the light switch on the bulbs get put in series with the yellow wire, the other side of the bulbs is ground, and your essentially ground out the ignition system.

Been there done that... Took me a couple hours of head scratching, went through all the wiring connections and verified everything was connected right, then i pulled the stator apart and found that the grounds from the coils were still attached to each other but broke free from the connection on the stator mounting plate. Fixed that ground and it was all good again.

The owners manual is available on my manuals server below, the wiring diagram is towards the end of the manual, page 55 if i recall! I spent a lot of time staring at that page... LOL

[1980atc_110]

Thanks for the replies, I'll do some checking and post what I find.

[1980atc_110]

I didn't have time to tear off the pull starter and the stator, but I did take out the headlight and switch. I checked the yellow (stator lighting coil wire) to ground and had continuity. I checked the yellow wire to ground, to both the chassis and then to the green ground wires in the headlight bucket.

Is this test acceptable? or should I pull the stator?

Thanks.

[barnett468]

Hello

Call me stupid but you say the light stays on but it dies. This means it has a battery. Does it have one? There is not one in the wiring diagram below. So don't blame me for not knowing. Anyway a wiring diagram and service manual url are below. Just left click on the blue line. The oscar mayer one takes a while to load.

If it has a battery and it is not new or not filled with battery acid instead of water in the beginning it could be the battery even though the lights go on. I know it sounds strange but i've had this problem before. It could also be the stator. In theory if you remove the positive battery cable while it is running it should keep running. Another test is take a volt meter and check the battery voltage not running, then start it and hold the rpm up a little. If the voltage increases by at least 1/2 volt then the stator is good so this eliminates one problem, if it stays the same or looses ANY voltage than something is wrong in the charging system.


Your comtinuity test is not a guarantee the connection is still not corroded enough to prevent sufficient voltage through it to keep it running with the lite on. I suhhest cleaning all grounds and connectors.


You need to open this with internet explorer browser because it has to be enlarged to 400% to be able to read it and firefox might not have this enlarging feature.

http://www.3wheelerworld.com/content.php/193-ATC110


http://www.oscarmayer.net/atc/manuals/honda/atc70-125_1985_and_earlier_servicemanual.pdf

[1980atc_110]

Hello

Call me stupid but you say the light stays on but it dies. This means it has a battery. Does it have one? There is not one in the wiring diagram below. So don't blame me for not knowing. Anyway a wiring diagram and service manual url are below. Just left click on the blue line. The oscar mayer one takes a while to load.

If it has a battery and it is not new or not filled with battery acid instead of water in the beginning it could be the battery even though the lights go on. I know it sounds strange but i've had this problem before. It could also be the stator. In theory if you remove the positive battery cable while it is running it should keep running. Another test is take a volt meter and check the battery voltage not running, then start it and hold the rpm up a little. If the voltage increases by at least 1/2 volt then the stator is good so this eliminates one problem, if it stays the same or looses ANY voltage than something is wrong in the charging system.


Your comtinuity test is not a guarantee the connection is still not corroded enough to prevent sufficient voltage through it to keep it running with the lite on. I suhhest cleaning all grounds and connectors.


You need to open this with internet explorer browser because it has to be enlarged to 400% to be able to read it and firefox might not have this enlarging feature.

http://www.3wheelerworld.com/content.php/193-ATC110


http://www.oscarmayer.net/atc/manuals/honda/atc70-125_1985_and_earlier_servicemanual.pdf

No battery. The light will come on, but it goes out as the engine dies. Reading my O.P. I should have worded the light coming on statement better :). The trike is all stock and pretty much unmolested. All of the factory wiring is intact.

This morning before work I disconnected the yellow stator wire at the connection by the carb. I tested the yellow wire on both ends (By the carb and in the headlight bucket) to make sure it's not grounding out, and it's not.

Before I pull the stator I wanted to test the voltage at the end of the stator wire in the headlight bucket. Any idea what it should be putting out for voltage at an idle? The wiring diagram says its a 6 volt 25w bulb so I @ss u me it should be at least 6 volts? any idea of the minimum voltage I should be getting? That way I can determine if the lighting coils are ok?

Also, I tested the headlight switch with an ohmmeter, and it checks out good.

Thanks

[1980atc_110]

Well I had some time to work on her today. I started checking the wires in the headlight bucket and discovered my ground wire wasn't grounded. I pulled the wiring harness and when the harness came out so did a bunch of acorns and fiberglass insulation ;). I guess the mice moved in and chowed my wires. I think what was happening was the headlight switch was acting like another kill switch. I'll get her all rewired and hopefully all will be good.

[kb0nly]

Good to hear... Electrical stuff will make you lose some hair sometimes, and critters sure love chewing on it.

[1980atc_110]

Good to hear... Electrical stuff will make you lose some hair sometimes, and critters sure love chewing on it.

I'm quite sure chasing electrical gremlins is, at least partially, responsible for me being bald ;). I have always struggled with understanding wiring and electrical systems (thank God these trikes are relatively simple). I rewired the trike from what was left of the main harness all the way back to the tail light, using the correctly colored and sized wire. Fired her up and all was good :), High beam, low beam, and tail light all work now :w00t:.

Thanks everyone for your responses and help:beer.

[kb0nly]

Great job! Also good to hear you color matched the wiring, will save you lots of headaches in the future if you get trouble. I saw a trike once that was rewired with nothing but a single spool of yellow wire... Yikes.

[ADOG1207]

Dang this post was answered already! I had the answer! :P bare wire somewhere touching ground. hit the lights, ground the circuit. Could have tested this by putting a DC volt meter up to a hot leg and a ground wire near the light, or anywhere really. fire it up, should read around 12 volts, hit the switch and if your volts drop then youve got a short somewhere. Also you mentioned yanking your stator. if you ever suspect your stator is fried, you can test it buy taking resistance readings in the harness plug that connects to your CDI box. the readings you should be getting can be found in the manual for your bike, they'll be something like 3.4-5.2 ohms. etc. Youll know what connects to what by the color of the wire cross referenced to your wiring diagram. same can be done for the CDI box itself or your Ignition Coil (IC). While im not great with motors, i get electricity :) glad you figured it out anyway. way to go!