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Cantedvalve

Turn Signal Side Markers... question

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I dont KNOW that I have a problem, but I want to ask.  I got all of the lights back in last night.  When I turn the lights on (no turn signal), the side lights are VERY dim.  When I engage the turn signal, everything flashes appropriately.  So the question is, should the side lights be dim when the turn signal is OFF?

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On to me is 100% bright.  In this case, dim is around 5-10% brightness.

My understanding of the whole thing was, when the exterior lights are on and no turn signal, that the side marker lights are both on 100%. When the turn signal starts, then it dims and brightens opposite the parking lamps under the grille.

The second part of that is working. The turn signal works as intended.  It’s the “no turn signal but lights are on” that I get the dim bulb.

I’m still looking into it.  To be honest, im not sure it ever worked the way I expected it to... which is why im asking.

 

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We need all the facts. So its a 70 and the marker light wiring isn't modified, and it has incandescent lights?

If the above is true then look at the attached pdf. The "left marker" lights are in series with the left front turn, left dash, and left hood lights. Under this condition the left marker lights should be bright. If you've modified something then all bets are off and your guess is as good as mine.

For everyone else not following this, the 70 has an oddball system where the marker lights flash alternately with the turn signals, but only when the headlights or park lights are on.

 

70 MACH EXT LITES 3,4 SIMPLIFIED.pdf

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You have all the facts.  Nothing has been modified.  The only wild card is that the gauge panel isn’t in the car.  So I am putting that back in today to see if it changes things (and to test the gauges).

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50 minutes ago, Cantedvalve said:

You have all the facts.  Nothing has been modified.  The only wild card is that the gauge panel isn’t in the car.  So I am putting that back in today to see if it changes things (and to test the gauges).

The third light in series will help brighten-up the marker lights and all should return to normal operation. I suspect that's why they only did this for one year- one little change to the circuit and odd things occur.

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CV and Mach1 Driver:

The 1970 rear side marker lights simply compare the turn signal line to the running light line.  If there is a difference in voltage between the two, the lamp will light up.  The bulb is a single filament.  If one signal configuration is bright, the other should be as well.  The only way one should be dim is if somehow the running light voltage is higher than expected elsewhere in the car due to a bad bulb or touching filaments, causing the running light line having some sort of leaking voltage. 

This design for 1970 absolutely sucks, especially for trouble-shooting. 

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I found a bad wire on the passenger side parking lamp... well, not sure it’s a bad wire as much as the contact isn’t making contact with the bulb.  At going back on the glitch list.

Speaking of glitches, my gauges didn’t work.  Also, it appears that my circuit card is shot... my left turn signal indicator was intermittently lighting up on its own today.  So I’m gonna scrap the card and hard wire the cluster.  I don’t have all the exact wire colors, but enough close to make it work.  So far I have the gauges wires, up, but since I do t have the bulb sockets yet, I haven’t been able to do much more than 4 wires.  Still, it’s something...

 

B546C337-AC29-400A-AD31-73B56242FF55.jpeg

7A02B213-1B87-4FA6-AF76-0D5C4D3E5E39.jpeg

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And just for fun, here are my side marker lights, turn signal on and off.  I did try putting an LED bulb in each socket... didn’t get any brighter.  I did find that, even though the front one lights up, the socket is a horrible mess... it’s almost like it’s oozing green puss.  So I have that to replace...

A4222B30-8890-4707-976F-7932F0CD0841.jpeg

9A7E76C7-B793-40F2-9A57-17E6F913D3E7.jpeg

85911D73-E96C-4982-B1EC-63C519B8F12F.jpeg

A4029EEB-E51E-4D34-87B0-0D1CCE076A2A.jpeg

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15 hours ago, Midlife said:

" it’s almost like it’s oozing green puss. "

You sure it's not bleeding Ford blue?

I dunno… but its nasty.

Speaking of nasty, I pulled the headlight switch, and it tests out okay (I think... got a new multimeter).  I want to clean it up and lube it... but don't see an easy way to disassemble it.  I assume I have to just make due with the way it is?  Anything I shouldn't spray on it cleaner-wise?  Brake cleaner bad?

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2 hours ago, Cantedvalve said:

I dunno… but its nasty.

Speaking of nasty, I pulled the headlight switch, and it tests out okay (I think... got a new multimeter).  I want to clean it up and lube it... but don't see an easy way to disassemble it.  I assume I have to just make due with the way it is?  Anything I shouldn't spray on it cleaner-wise?  Brake cleaner bad?

You have to straighten the metal tabs to disassemble the switch.

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2 minutes ago, aslanefe said:

You have to straighten the metal tabs to disassemble the switch.

Never mind, looks like 70 switch is riveted instead of bent tabs. You can always drill out the rivet and install new ones or bolt and but.

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Hehehe.... bolt and butt...

I did drill out the rivets.  Looks like they are 1/8" x 7/16".  I got the contact areas cleaned up, regreased, and reassembled.  Works much snoother now.

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