headlight switch removal

[Rindelmach1 14]

I'm trying to remove my headlight switch from my 69 mach1 as I suspect its the reason why by dash cluster lights do not go on anymore. headlights work fine though as well as courtesy lights.  I've watched the youtube videos and pretty much read other threads on this.  My headlight switch has the button facing right side and I can get to it from underneath.  I've tried pressing it then pulling the knob. tried pulling the knob to on position then pressing button. also tried turn knob to courtesy lights position, pressing button then pulling knob.  is there anything that i am missing?

[Mike65 475]

Rindelmach1, when you press the button in on the switch, pull out on the knob, & the knob & the shaft should pull out of the switch. When you are pulling the knob if it stops coming out or you feel resistance release the button & then press it again all the time while pulling out on the knob. It should come out.

[Rindelmach1 14]

Bingo!  I followed your advise but had to play with it for a while.  What did the trick was holding the button, pulling the knob to on position but keeping the pressure on while I twisted it clockwise. Eventually it slipped out. 

Is there a way to test the dash cluster lights with a voltmeter?  want to test or give it another try before i buy a new one.  it looks pretty clean. 

[Rindelmach1 14]

I actually used a continuity test between the battery pin and different pins on the switch.  i have continuity between B and I. Also between B and the coil when I pin is pressed against it.  I DO NOT have continuity between B and D1, or D2. Even when I turn counterclockwise to courtesy light position.  Not sure how to test internal fuse. Any advise? thanks 

[Midlife 814]

Your rheostat or wiper on the rheostat is bad in all probability.  Replace the switch.

The circuit breaker really doesn't enter into the circuit and from what you describe, neither does the fuse box fuse for the dash lamps. 

[Mach1 Driver 560]

2 hours ago, Rindelmach1 said:

I actually used a continuity test between the battery pin and different pins on the switch.  i have continuity between B and I. Also between B and the coil when I pin is pressed against it.  I DO NOT have continuity between B and D1, or D2. Even when I turn counterclockwise to courtesy light position.  Not sure how to test internal fuse. Any advise? thanks 

The breaker shown is 15A, and there is another that is not shown that is 18A, just in the H circuit, for the headlights.

D1 only connects to D2, and only when the knob is turned CCW. You will feel the detent- its for the courtesy lights. To test the 15A breaker you should get continuity  from B to A all the time. To test the 18A breaker you should get continuity from B to H with the knob pulled all the way out.

I'm not sure what you mean by : "Also between B and the coil when I pin is pressed against it". You should have resistance between R and I and it should vary as you turn the knob from hi to lo- try different resistance scales. This is the variable resistor for dimming the 8 dash, 1 ash tray, 1 radio, and 2 clock lights.

[Rindelmach1 14]

I will pick up a new switch from advanced auto parts today.  i wanted to test for the variable resistance so thanks for the advise. I'll check ohms between R and I 

[Rindelmach1 14]

New switch is in but still don't have the dash cluster lights. A bit of a mystery.  Headlights work, courtesy lights as well but just not the cluster lights.  I guess I should check continuity between the cluster light wire on the switch to the plug that goes into the dash cluster? i think this is the blue wire with red strip that is on the headlight switch plug.

[Rindelmach1 14]

Now the door lights and courtesy lights do not go on with new switch.  Funny thing is i turned CCW before mounting the switch and the courtesy/door lights worked. Then had a hard time getting the switch mounted but eventually got it.  After the door/courtesy lights don't work.  I then removed it again, jumped the pins on the harness to test and it worked. Put back new switch and doesn't work.  Then put back old switch and doesn't work.  I can't believe this is evening happening. Never had a problem with door/courtesy lights.  Just cluster lights.  Back to D1 and D2. Shouldn't I have continuity between B and D1?  Also does the switch ground when mounted? maybe since its dangling, then maybe its not touching ground. 

[Mach1 Driver 560]

1 hour ago, Rindelmach1 said:

1. Back to D1 and D2. Shouldn't I have continuity between B and D1? 

2. Also does the switch ground when mounted? maybe since its dangling, then maybe its not touching ground. 

1. No, look at the diagram. The dashed line is not a connection, it only shows that it is controlled by the knob when turned CCW. There should be continuity only between D1 and D2 when turned CCW, and nothing else.

2. No, It shouldn't. You could test it by completely disconnecting all the wires, put one test lead on the mount, and the other to every terminal in off, park , and on. There should never be continuity. You have a loose connection somewhere.

[dcm0123 15]

Check the connector on the headlight switch. They are known to go bad.

Look for signs of heat damage to the plastic or damage to the metal sockets in the connectors.

Verify the metal socket in the connector engages the spade on the switch when you connect it.

The fuses for the courtesy light and dash lights are in the fuse box, not the headlight switch.

[Rindelmach1 14]

thanks.  will check and report back.  I guess the connector socket for D1 is a 12v feed from from fuse box?  i guess how else would courtesy lights get power if not from socket feeding B

[Mach1 Driver 560]

[Midlife 814]

The schematic for "charging" is for the ammeter version; a different schematic is required for the alternator indicator lamp.