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Ignition switch: gen and oil pressure lights stay on

Electrical issues
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59FL
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Ignition switch: gen and oil pressure lights stay on

#1

Post by 59FL » Tue Jul 21, 2009 12:59 pm

I recently installed a 5 pole tank mount ignition switch, wire harness and a 12 reg and gen.

The oil pressure switch, reg, and gen are known good ones, but the gen and oil presseure lights stay on when the ignition switch it energized. I followed the 1959 wireing diagram (I think) to a T. Obviously at least two wires minimum are wrong. Help.



Ohio-Rider
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Re: Ignition switch

#2

Post by Ohio-Rider » Tue Jul 21, 2009 2:06 pm

They should both light up when the switch is turned on. Do they go out after starting the engine? Or did i misunderstand your question?

awander
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Re: Ignition switch

#3

Post by awander » Tue Jul 21, 2009 3:51 pm

...the gen and oil presseure lights stay on when the ignition switch it energized.
Did you mean to write: "...the gen and oil presseure lights stay on when the ignition switch ISN'T energized."?

If so, then you have discovered what I did many years ago-some of the repop switches work differently than the originals. As I recall, you need to swap the wires around between 2 of the psots.

I have a drawing of this at home-i will try to dig it out and post it later tonight.

59FL
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Re: Ignition switch

#4

Post by 59FL » Sat Jul 25, 2009 5:56 am

My bad, the oil light goes out when engine is running, the generator light remains lit.

I am pretty sure it is a wire and not the NIB generator, regulator, and coil, installed when the bike was converted from 6v to 12v a few weeks ago.

steve_wood
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Re: Ignition switch

#5

Post by steve_wood » Sat Jul 25, 2009 1:24 pm

The generator light has two connections: One is power from the battery, one is power from the generator. If the generator is not producing electricity, then that lead effectively becomes a ground and the current flows from the battery, through the light (it shines) through the generator lead and to ground. If the generator is producing electricity, the current from the generator and the battery oppose each other so no current flows and the light does not light.

Long story short, for some reason, there is no current coming from your generator along that lead to the generator light. Get your voltmeter, and trace backwards from the generator light connection until you find where the fault is.

59FL
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Re: Ignition switch

#6

Post by 59FL » Wed Jul 29, 2009 11:49 am

Please bare with me as I am somewhat (very) ignorant about electrical stuff.

I tested the generator as per the SM and it is working, the SM made it sound like testing the regulator required tools I did not have so I am taking it on faith that because it was/is NIB it works.

The green wire from the A post on the generator goes to the center contact of the gen light socket, the side wire on the gen light housing goes to a post on the dash where the other 2 light socket side wires and a black wire from the main harness are ganged up. This post shows grounding to the chassis, but according to my interoperation of the wire diagram, the 5th wire to this post is a jumper to ignition switch terminal #5 which is 12v when the ignition switch it turned CW.

The strange thing to me is the other two dash lights (Neut/Oil) work wired this way.

I don’t get the chassis ground and the 12V deal, the screw (post) insulators have been replaced.

FlatHeadSix
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Re: Ignition switch

#7

Post by FlatHeadSix » Wed Jul 29, 2009 2:16 pm

59

You are NOT reading chassis ground when you test those side connections with your ohm meter, you are reading resistance in the circuits; light bulb filaments. A digital meter will tell you exactly what that it is, an analog meter will usually just peg depending on the range setting and give you what appears to be a grounded connection. Remove the bulbs from the sockets and see what you get.

All those light sockets should be insulated (isolated) from the dash base and none of the connections on them should be grounded. Each light gets its "ground" from a different source; the OIL light receives ground from the pressure switch, the neutral light receives its ground from the switch on the tranny, and the GEN light circuit completes either through the output of the generator or from the relay depending on the type of system.

mike

59FL
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Re: Ignition switch

#8

Post by 59FL » Wed Jul 29, 2009 3:30 pm

Mike, thanks for the reply, I put new isolators on the dash posts (terminals) but it grounds when the light socket side wires are connected. I am thinking the light socket(s) are grounded to the dash plate, it's old and oxidized. Whats the recommended fix if the socket(s) are gorunded, repair or replace the dash?

I assume there is some sort of non conductive sleeve or spacer used to mout the sockets to the dash. Do the scokets press out?

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Re: Ignition switch

#9

Post by FlatHeadSix » Wed Jul 29, 2009 4:13 pm

the sockets are crimped to the dash plate and insulated internally with fiber rings. Before you start knocking them out of there I would remove the bulbs and disconnect the leads and carefully test each socket again with a good digital meter. The only way to accurately test the sockets is when they are independent of the rest of the circuit, otherwise you will get false "ground" indications by reading the resistance in other components connected to the circuit.

If those sockets were actually grounded to the dash plate as you suspect, and you had a fully charged battery connected to the system, you would quickly smoke the wires the instant you turned the switch on. If the lights come on and the wires don't smoke then your sockets are OK.

mike

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