capemustang

The headlight connector, per se, is not at fault, it is only a phenolic block.  The pins that go into the headlight connector can be suspect, and often times I need to re-crimp the pins to get good continuity to the rest of the wiring system.

Sometimes the connector goes causing the switch to overheat and fail. Replacing the switch when this happens is a temporary solution unless you replace the mating connector.
If you can get it to work, leave it on for a while then touch the wires coming out of the connector with your hand. If you feel heat, replace the connector as well. Unplug the connector and look for signs of burning on the electrical sockets or plastic inside the connector. This is a sign the connector is bad. If the contact is bad enough, you may not be ale to get the lights to work.
As mentioned above many people buy a relay kit and use the switch to only pull in the relay. The advantage of this is you do not run the high current the headlights requires through the switch. This current is what causes the connector and switch to fail.

Got the clear all done and unmasked it. Here’s the finished interior paint. 

I just had a talk with the guy about it.  He used to have a car that this came out of, and that car was sold many years ago.  Unfortunately the unique wiring harnesses that go with the tack were sold with that car.   He is going to put it on ebay motors soon, and raise the price.   So if anyone wants this, jump on it now.  Midlife can probably either modify your existing wire harnesses to accept it. 
The price on ebay will probably be cosiderable more, because of the fees involved. 

Heres my reasoning:
1. The car has 41 total lights
2. Excluding the headlights (there will probably never be LEDs that are DOT approved), the incandescent lights eat up 26.42 amps. LEDs would consume only 4.51A. That's an 83% amperage savings. Yes I know they won't all be on at once, and I know what will be on when I'm driving at night.
3. The stock alternator is what 35A-38A? Even with the change to LEDs I still need to change to a 95A alternator just to run the stuff I want to upgrade. I won't be running radiator cooling fans because that's another 22A. I will add EFI, an electric fuel pump, power windows, improve the radio output, halogen head lights, MSD 6AL, cruise control, transmission control, and various other amperage sucking devices.
4. I've run the numbers and the only way not to upgrade to a 130A alternator (which would require a serpentine belt system and electric cooling fans) is to eliminate the incandescent lights. I'm pretty passionate about keeping the stock look, and a serpentine system is definitely not a stock look. 

OK, now I understand a bit more.  The connections for the hood scoop lights is (as you said) a 4 wire connector for a 70.  That changes things.  It also changes things because I think the front parking/turn lights are wired different on a 69 and 70.  What you need to disconnect is the front combo turn signal/parking light, not the front side marker light. I am not sure you can disconnect them in a 70.  What you can also do is remove the front combo bulb on both the left and right side.
There is another easy thing to try that could indicate where the problem is.  This only works if you have an old style flasher.  If you have an electronic flasher installed, it will not work.  But what you need to try is to turn on your left turn signal.  Take a note of the speed it is flashing.  Then turn on your parking lights, and see if the speed of flashing changes.  Do the same with the right turn signal.  If you have a factory style flasher, and the speed of flashing changes with parking lights on, this could be a clue.
One other question... did this 70 Mach work correctly at one time, and now it is not?  Or has it always worked incorrectly like this?

I went through this in 2006. It is very scary. The hardest part can be waiting to hear the biopsy results and what treatment is the best. Take your time to get more information before committing to a course of treatment.  Try to be patient with each other and take care of yourselves--yes, even you as the spouse need to make sure you are ok.  You will get through this together. I will be praying for you and your family.

I'd install a relay for the headlights. Takes the heat off the switch and let's the relay do the work. It also increased the brightness of my stock lights. If I can do it,  anyone can. I believe this is how I wired mine. 

While I was at it, I also did the horn which Mustangs have a history of fire issues with especially after market steering wheels. 

Just a thought. 

This might help you.  

 

I have not used by trunk key in 20 years!  The simplest and best addition to you ride. 

Contrary to that thread link, the knobs just unscrew.  Pull the shaft out to full extension, grip the shaft and unscrew the knob.  Since you can buy new knobs, if the removal is really tough you can just grip the shaft with something and gorilla the plastic knob if necessary to unscrew it.  Then use a new knob when you reassemble.

Thanks for clearing that up.  https://www.vintage-mustang.com/threads/69-mustang-clock-knob-removal.587881/  Brian 

I finally got my clock ticking again. After removing my clock to check out why it wasn't ticking, i notice the contact broke off but that was 1 of 2 issues. I ended up soldering it on after 1000 attempts only to find out that the solenoid was burnt out. I found a company that makes the original electromechanical kit and replaced the guts with NOS. I am a stickler for originality and didn't want to convert to quartz.  I'll point out a few things that I'm sure will help the next guy.  The clock set knob does not come off.  I had to take off the sprocket (cog gear) by using a gear puller. Made a small plate with a slit to fit behind the small sprocket and attached a screw to the point of the gear puller so it would fit the tiny post on the gear. Then after a few steps i pulled the guts and replaced them.Kit cost $85 which was well worth it consider broken clocks are going for >$150.  anyone needing advise can reply. thanks

104-12t electromechanical kit
https://www.clocksandgauges.com/electric-clock-repair-kit.html

OK, I am going to go throw a weird one at you.  Maybe your problem is related to mine, but probably not.  your problem is more likely a connection problem. However,  I had a similar radio cutting out problem with my retrosound, except mine would cut out when I revved the engine from low speed to high, but it only seemed to happen when the car was fresh out of the garage.  Also, if the car was brought back to dead idle, radio would play again -even fresh out of the garage. weird thing was, drive it a few miles, and this cut-out would go away.  
So, after me living with this for a long while, and pondering it, but not coming up with anything, a friend rides with me and sees this weird behavior and has a genius insight - he says "do you have an original voltage regulator?"  yes.  "well then, I think maybe your radio is seeing unacceptable voltages when the alternator is kicked in at higher RPMS.  The alternator kicks in much more often immediately after the car has started after it's been sitting in garage.  After you drive the car a bit, the battery gets charged up - so alternator not kicking in - and symptom stops.   Maybe you should try a new solid-state VR." 
Freaking genius insight.  Sure enough, a new solid state VR solved my radio cutting out problem completely.
Now, in your case, the radio cuts out at low speed - when another electrical system is engaged.  So perhaps the current draw of the blinker system causes the voltage the radio is getting to somehow change to a temporarily unacceptable amount.  Car equilibrates voltages are a few moments and radio comes back on.  At high RPMs voltage is sufficiently regulated to not cause a problem in the circuit.  Do you have an old-style VR with resistors on the back? is a good question to ask if you can't trace it to bad ground or bad connection.

Above image is what the back of my old VR looked like (I believe it is original with the car).  The new Solid State versions don't look like this.
Most likely, this is not your problem, but at least I stuck to the "radio cuts out" theme.  Hope this wasn't too much of a thread high-jack!
 
Jay

Just wanted to let every one know that I installed the carb on my Mustang about two weeks ago.  It fired right up on fast idle.  Once warm I adjusted the idle screws to get a smooth idle and drove it.  No problems.  Easy.   I want to thank Daytona Parts Company for the carb kit and more importantly Tim at Daytona Parts for all the tech help he provided to me before and during the rebuild process.   I also want to mention that I used a new float in this rebuild from Mike's Carburetor Parts.  Never had to call them, but the float fit right and seems to be working.  Hopefully it will end the problem I had with the old float taking on gas and screwing up the float level.    I have no interest in these business just hope that some one, some day finds this thread helpful.  

So after 5 years of not having a running engine in my Mustang we finally got the new one going. Life get's in the way and before you know it time has flown by.
Of course it didn't just fire right up with no problems though. 1st we had a bad coil which took a few hours to figure out. Then we had the firing order screwed up. It has a Trick Flow Stage 1 cam which complicated the matter. It would run on the Trick Flow and stock firing order, but was backfiring pretty bad. Took my son and I a day to figure out that the firing order goes counterclockwise, not clockwise, duh! It's actually my fault, but in my defense it's been 40 years since I even thought about a firing order, lol.
I still have some wiring to clean up and a whole lot of body work to go, but it's a huge step for me and has me motivated to get it done.
Thanks to the forum and especially Mach1 Driver for his awesome wiring diagram.
 
 

Got my replacement grille.

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.

I wasn't trying to be a dick. I got the impression from your post you didn't have a clue and was suggesting nicely you become familiar with some of the basics. You want cleveland specific, check out http://351c.net/board/ and https://pantera.infopop.cc/
Both are excellent resources and some of the experts are on both.

I am so sorry. I can only imagine what you are going through right now. What a truly crappy thing to happen. This truly stinks, but I am glad that you didn’t lose your car.   There are some real ass***** out there. I hope that things get better.

You may want to talk to a lawyer just to see if you have any recourse with the facility. I'm sure you signed an agreement that says "the owner of the facility assumes no liability" but there is such a thing as "reasonable expectations". It is reasonable to expect a storage facility to be secure against fire and theft, etc.

That is awful. I hope that you get some compensation from insurance. Its’s odd that they put a cheap lock on after breaking into your storage unit.  If you haven’t already, you might speak to the police to see if they have any information about this happening to other people.  I am really sorry this happened on you.

To all,
The following is in reference to electrical distribution of my 69 Mach One, which I adopted from VicFreg. Much time and effort was put into carefully installing my electrical system but as you can see a failure of materials could be catastrophic.
Wanted to drop you a note and thank you. As you may recall, I copied your electrical lay out with the battery / solenoid in the trunk, on/off switch, fuse protection and two distributions (one behind AC in passenger compartment and one in engine bay). Yesterday I was test driving the car and the entire electrical shut down. All dead. I got the car home and started to trouble shoot via a meter. Sure enough, the 175Amp fuse on the battery board blew. So I started to ohm out each wire on the distribution block to see which one was connected to ground (which caused the fuse to blow) because the main wire distribution wire actually ohm'd to ground. First wire I disconnected and tested was the alternator (as this block was much easier to access, and the alternator was the top connection). Once the alternator wire was removed the system no longer had conductivity to ground. Now I know somewhere along that wire ground contact is being made. The wire appeared good, no abrasions, visible, the wire is also in a wire sleeve by itself. The wire lug connections appeared to to be good, had no Idea why the the power post from alternator would be touching ground. Further inspection showed a burn mark on the hold down bolt. Thought maybe the post arched to ground. As I was rotating the wire to reattach to the post, I flipped it over and noticed a small split in the heat-shrink that actually made contact with the alternator housing, that was the culprit.  I put another sleeve of heat shrink over it followed by electrical tape. Reassembled and all is well. I want to thank you for the protection suggestion of the 175Amp fuse.  This would of been much worse if the fuse was not there. A $5 dollar fuse saved a very expensive project. I'm still in a bit of a stress breakdown as I continually think of the what may have happened if I did not follow you suggestions.

Heres my advice.  Just pull all your wiring and send it to MidLife for rework.  All the connectors will be original (AND THEY WILL WORK). buying rewiring kits, and mainly the BS associated with making them work is stupid as long as MidLife is around.   Don't re-wire you car - just get MidLife to fix it.  Probably less cost... 1000% easier!