806 Flashing AMP Light....

Absent Minded Farmer · Oct 19, 2014

What causes the AMP light to flash continuously when the key is off, go out when I turn the key on & it stays off with the engine running?

Mike

Owen Aaland · Oct 20, 2014

Either a wiring problem, bad key switch, or a shorted diode in the alternator if it has been converted to a 10SI internal regulator alternator.

The diagram below shows how the later 806 tractors with 10DN alternators were wired. A shorted diode in these alternators could keep the field relay closed but there still should not be any voltage in the wires between the switch and regulator.

Absent Minded Farmer · Oct 20, 2014

My apologies, I forgot some important info! It's a gasser with a genny.

So far, I left the battery unhooked over night & the symptoms changed. Now, the ALT light stays off when I turn the key on, comes on & stays on while the engine is running until about half throttle & then it goes out & stays out regardless of the RPMs. When I kill the engine, the ALT light illuminates solid for maybe half a minute & winks out.

So far, the only thing I have replaced today is the key switch & it made no difference. Is there a contact in the VR that's stuck shut?

I know I should rewire the tractor, as most of the wires are original. I'm just hoping to gimp it along until I can divert money into the differed maintenance problem next year at some point.

Thanks,
Mike

Owen Aaland · Oct 20, 2014

Most likely it is a sticking relay in the regulator. One side of the light comes from the key switch. The other side is attached to the GEN or ARM terminal of the regulator. When the key is first turned on the light grounds through the brushes and armature of the generator. When the generator starts to charge the voltage rises on that wire until the cutout relay in the regulator closes. When the relay closes the voltage is the same on both sides of the bulb and the light goes out. If the relay sticks closed the BAT terminal is still connected internally in the regulator to provide power in the GEN terminal. When the switch off you still have power coming from the regulator going through the bulb and grounding through the ignition system and fuel gauge which causes the light to glow.

Absent Minded Farmer · Oct 21, 2014

Yes, it was the regulator. I got a new one in this afternoon & haven't had any problems since.

Thanks Much!!

Mike

806 Flashing AMP Light....

Absent Minded Farmer

Well-known Member

Owen Aaland

Well-known Member

Absent Minded Farmer

Well-known Member

Owen Aaland

Well-known Member

Absent Minded Farmer

Well-known Member

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