Turn signal hooped

[forexbob]

I've narrowed the electrical problem down to the turn signal itself. I'm not an electrician (and if you saw my other recent post, not a machinist either), so I'm not sure how to diagnose the problem. It can't be that difficult though...there's not a lot to the thing.

I checked resistance from the wire connector to the seat of the bulb and the meter went off the scale, which I believe to be appropriate. I checked it from the wire connector to the bulb housing and got nothing. I checked between the bulb seat and the housing and got nothing.

All of this I believe is correct, so my belief has got be wrong somewhere.

Where am I screwed up?

Thanks
Bob

[TopCatGr58]

Hey Bob,

You didn't say whether you were talking about the front or rear, but since you stated 1 wire, I'm going to assume you meant the rear...the front has 2 wires for both running and turn signal. Please refer to the diagram below!



The bulb socket should be the NEGATIVE side, and so a continuity/resistance test from it to the base should show little/NO resistance. The WIRE you spoke of should be the POSITIVE, and so when you say the meter went off the scale...I'm assuming you meant that the meter was showing very high resistance or NO continuity...which is what it should be. ONLY if you had a bulb in the socket should you then get continuity=no resistance from the (+) wire end to the bulb casing/shaft.

You should find no resistance measuring from the bulb socket base to the signal housing. There is a connector/prong down on the INSIDE center of the bulb socket, that is the end of the POSITIVE wire, and you should get little/no resistance from the wire to that prong...it's insulated from the rest of the bulb socket!

Finally, in the diagram you see the wire with the large washer that connects to the shaft of the signal housing....it's the GROUND wire that connects to the wire harness, but also provides a ground via the contact with the fender/frame....but it can get corroded/rusted and not make good contact and a poor ground can result.

Hope this helps your troubleshooting!?
T.C.

[forexbob]

Fixed it!

So I took it down to this:


And when grounded properly, it works fine.

The question is then, why does the left signal not ground properly when the right one does? They're set up the same way.

So there's a little tang on the right side that apparently is the ground and is not on the left side. A little lock wire and the problem is fixed.

Why would there not be a tang on the left side like there is on the right? It doesn't look as though it's been broken off. It doesn't look like there was ever one there. And it certainly didn't come with the left rear turn signal not working.

[natemoen]

Probably because that socket has been replaced due to rust. I haven't seen much for replacement sockets with that tab.

[forexbob]

Posted the previous without refreshing

Thanks TC,

Interesting diagram. No wonder I was having problems. My set up isn't anything like that.

I used a piece of lock wire to ground the signal stem to the frame and it works fine now.

Time to grab another beer and sit in what's left of the sun.