1970 Mustang Exterior Lights (turn signals)

[Mach1 Driver 560]

BSWOR you should consider pinning this post also. 

Since completing my 1969 Mach1 Schematic (see A REAL Schematic) I have seen a lot of confusion about 1970 turn and marker lights. I didn't know they were different than the 69, but they sounded interesting so I investigated to see if I wanted to upgrade. After reviewing the circuit I decided to leave well enough alone, but hopefully the attached three pages will help explain their operation for those poor souls with 70s ;) 

1970 MUSTANG EXTERIOR LIGHTS PAGE 1.pdf

1970 MUSTANG EXTERIOR LIGHTS PAGE 2.pdf

 

1970 MUSTANG EXTERIOR LIGHTS PAGE 3.pdf

[aslanefe 333]

An other great job, thanks a lot. Wonder why they changed the design for 70 ?  Do you see any advantages/increase in reliability etc between 69 and 70?

[Mach1 Driver 560]

Most companies are "Marketing" driven. Someone in engineering had a wet dream and came up with this wonderful new feature where the marker lights would flash alternately with the turn signals. I imagine it looks neat. And all they had to do was delete the ground on the marker lights and wire it into the flasher circuit. It just required some added wire, so it was easy to do. It looks like something I might of come up with in my yout.

Now, as I was sayin Your Honor, the down side is that it doesn't always alternately flash. If the headlights are OFF the marker lights flash in sequence with the turn signals. Aw but the exuberance of yout overlooks this minor drawback. I recently read a post on VMF where a guy in England (I think) started pulling his car apart trying to figure out what was wrong. And of course he got the usual "helpful" suggestions- until I told him it was normal operation. The marker lights are in series with anywhere from 3 to 10 other light bulbs depending on whether the headlights are on or off. If one of the 1157 bulbs burns out or looses its ground then it could take a while to figure out what went wrong. I find the circuit more than a little "screwy".

The movie above is of course "My Cousin Vinny" and ya gotta love Mona Lisa Vito's testimony- that girl knows her cars. 

[Mach1 Driver 560]

On 7/25/2017 at 8:38 PM, aslanefe said:

An other great job, thanks a lot. Wonder why they changed the design for 70 ?  Do you see any advantages/increase in reliability etc between 69 and 70?

To better answer your question, I refer you to our harness guru Midlife, who makes a business of actually restoring Mustang wire harnesses:

There are distinct differences between the 69 and 70 underdash harnesses, with the 69's being far superior in design/reliability. For the 64.5-8's, there's not much difference in functionality, except the 67/68's include as integral the wiper system, e-switch system and a separate dash cluster. For the 64.5-68's, much of the additional features were separate harnesses that plugged into the main underdash; these included A/C, consoles, courtesy lights, etc.

 

 

[Midlife 814]

On the 69's, the side lights were only running lights; on the 70's, it was a combination running lights and turn signals.  I wouldn't be at all surprised that there was a Federal mandate to have turn signals on the sides of vehicles for safety reasons.  The running lights were mandated in 1968.

[unilec 57]

Good to know all this, so thanks for taking the time and posting. :-)

[Cantedvalve 128]

Wait... so the shit show that Ford made of the markers and turn lights was INTENTIONAL?!

I've been wanting to get LED bulbs for the markers (the 194 ones) to accompany the inevitable LED taiillights from vintageleds.com, but according to Gary at vintageleds.com they wont work due to the awful way that Ford wired things.  And from this article, it seems they did it for a marketing trick?  Now I need specific "isolator" bulbs for the side markers to get everything working.

Do I have that about right?  SMH...

[bigmal 225]

I have a 69. In Australia I had to change my headlights to drive on the left side of the road. My parking lights are now in the outer headlights. The blinkers are just blinkers. As the blinkers are a little hard to see from some angles so I changed the outer marker lights to blinkers just for better visibility. Seems to work well.

[Mach1 Driver 560]

On 10/29/2018 at 2:35 PM, Cantedvalve said:

Wait... so the shit show that Ford made of the markers and turn lights was INTENTIONAL?!

I've been wanting to get LED bulbs for the markers (the 194 ones) to accompany the inevitable LED taiillights from vintageleds.com, but according to Gary at vintageleds.com they wont work due to the awful way that Ford wired things.  And from this article, it seems they did it for a marketing trick?  Now I need specific "isolator" bulbs for the side markers to get everything working.

Do I have that about right?  SMH...

LOL, yes it was intentional. Someone must have thought it was really cool. I haven't looked into it, but I would rewire it like a 69 and use all LEDs. They aren't that different. You'll need a 69 wire diagram. How electrically savvy are you? Is that something you would attempt?

[Cantedvalve 128]

Okay, so I continue to study this. Diagram 3 shows the flashed on, which means the part and tail turns are on, but side markers are off.  Then the flasher turns off for diagram 4. This creates the ground route for the side markers, but shouldn’t it turn the park and tail turns off?  The diagram shows tail turn off, but park turn still on?  Why is the left park turn on?  Why are the hood turns on all the time?

[Mach1 Driver 560]

16 hours ago, Cantedvalve said:

Okay, so I continue to study this. Diagram 3 shows the flashed on, which means the part and tail turns are on, but side markers are off.  Then the flasher turns off for diagram 4. This creates the ground route for the side markers, but shouldn’t it turn the park and tail turns off?  The diagram shows tail turn off, but park turn still on?  Why is the left park turn on?  Why are the hood turns on all the time?

BTW, if you quote someone the site will email them to let them know someone needs a response, otherwise they have to look down here to see the post.

Anyway, I know a whole bunch of stuff is happening at once in this circuit, so I made an attempt to simplify it. See if this helps- see attached

70 MACH EXT LITES 3,4 SIMPLIFIED.pdf

[Cantedvalve 128]

@Mach1 Driver or you could just tag them :)

That diagram is much clearer. Okay, so now what happens when you put LEDs in the side markers?

[Rich Ackermann 174]

On ‎11‎/‎8‎/‎2018 at 10:15 PM, Mach1 Driver said:

LOL, yes it was intentional. Someone must have thought it was really cool. I haven't looked into it, but I would rewire it like a 69 and use all LEDs. They aren't that different. You'll need a 69 wire diagram. How electrically savvy are you? Is that something you would attempt?

Hello, I am a Newby to the 1970 model year. I have restored a few 1973s and owned a 1969. I found this thread very helpful in understanding the 70 model year's "unique" electrical wiring characteristics.  I want to eliminate the side marker blinking behavior and have the side markers operate like the 1969, 71-73 model years. So, I have been looking at both the 69 and 70 wiring diagrams, and if I am not mistaken, by simply disconnecting the front and rear side markers from their respective RH white/blue and LH green/white (blinker) wires and reconnecting the bulb wires to a constant ground they will no longer work in series and should stop blinking. The front parking/turn signals should continue to work as they did before as they should continue to find ground somewhere on the circuit (at the hood, dash, etc). In my situation, I have to replace the front parking/turn signal assemblies anyway so I am going to buy the 1969 three wire version, which unlike the 1970 two wire version, have a third wire for ground.

My car is completely dissembled at this time, so I cannot test my theory/understanding above. Can anyone confirm that I have this right or wrong?

Thanks,

Rich

[Mach1 Driver 560]

57 minutes ago, Richard Ackermann said:

Hello, I am a Newby to the 1970 model year. I have restored a few 1973s and owned a 1969. I found this thread very helpful in understanding the 70 model year's "unique" electrical wiring characteristics.  I want to eliminate the side marker blinking behavior and have the side markers operate like the 1969, 71-73 model years. So, I have been looking at both the 69 and 70 wiring diagrams, and if I am not mistaken, by simply disconnecting the front and rear side markers from their respective RH white/blue and LH green/white (blinker) wires and reconnecting the bulb wires to a constant ground they will no longer work in series and should stop blinking. The front parking/turn signals should continue to work as they did before as they should continue to find ground somewhere on the circuit (at the hood, dash, etc). In my situation, I have to replace the front parking/turn signal assemblies anyway so I am going to buy the 1969 three wire version, which unlike the 1970 two wire version, have a third wire for ground.

My car is completely dissembled at this time, so I cannot test my theory/understanding above. Can anyone confirm that I have this right or wrong?

Thanks,

Rich

Yep, that will work. I don't have a 70 so I can only confirm from the schematic, but I did write this entire post by looking at the diagram and converting it into a schematic ;)

[Mach1 Driver 560]

1 hour ago, Cantedvalve said:

@Mach1 Driver or you could just tag them :)

That diagram is much clearer. Okay, so now what happens when you put LEDs in the side markers?

Could you explain the first line? 

If bulbs are still in the turn, dash and hood, then side marker LEDs will work. If everything is LEDs then I doubt you would like the results- the LEDs may fire but be dim when the flasher opens, resulting in dim side markers and all the turn LEDs never going out.

 With all LEDs it would be better to do what the post directly below your post is doing (Richard Ackermann), and convert it to a 69 style. 

[Cantedvalve 128]

@Mach1 Driver you can tag a username by putting an @ sign in front of the name and it will do the same thing as quoting I believe... without the quote.  Maybe not.

I am putting my lights back together, and one thing I need to do is get some new bulbs. Just trying to decide on LED vs incandescent.  Also need to decide on using GTONavy’s sequential tail lights at some point.

[Mach1 Driver 560]

I will change everything in mine to LED. It will drop the load on the electrical system considerably. I'm trying to find LED tail lights with no hot spots so it won't look like a bunch of LEDs behind the lens. Maybe if I cut up a fluorescent light lens and position that between the LEDs and the car lens it will diffuse the light enough.

[Rich Ackermann 174]

7 hours ago, Cantedvalve said:

@Mach1 Driver you can tag a username by putting an @ sign in front of the name and it will do the same thing as quoting I believe... without the quote.  Maybe not.

I am putting my lights back together, and one thing I need to do is get some new bulbs. Just trying to decide on LED vs incandescent.  Also need to decide on using GTONavy’s sequential tail lights at some point.

I have been looking at these LED kits from HiPo Parts. I spoke to them and they seem very knowledgeable and willing to help you get the right setup. They also carry LED bulbs that are non-polarized which may solve the 1970 reverse polarity parking light issue, but I have not tried so I am not certain. I sure the guys at HiPo Parts would know.

https://www.hipoparts.com/1969-70-ford-mustang/

[RPM 1,190]

18 hours ago, Mach1 Driver said:

I will change everything in mine to LED. It will drop the load on the electrical system considerably. I'm trying to find LED tail lights with no hot spots so it won't look like a bunch of LEDs behind the lens. Maybe if I cut up a fluorescent light lens and position that between the LEDs and the car lens it will diffuse the light enough.

This is the reason I haven't installed LEDs in the tail lamps. Please let us know if/ when you find a solution. 

[Mach1 Driver 560]

5 hours ago, RPM said:

This is the reason I haven't installed LEDs in the tail lamps. Please let us know if/ when you find a solution. 

Well there is one alternative- something like the plasma bulbs sold by West Coast Classic Cougar. Since they are a bulb of sorts, they have the light source in the location that the lens was designed to disperse, so its just a cranked-up version of the original bulb. Plus most of the light comes out the sides and it is reflected out.

Of course the thing you loose with this type, is the sequential turn feature, which I've been in love with since the 64 T-birds came out with the little distributor to do the job electromechanically.

[Mach1 Driver 560]

On 11/23/2018 at 3:17 PM, Cantedvalve said:

I am putting my lights back together, and one thing I need to do is get some new bulbs. Just trying to decide on LED vs incandescent.  Also need to decide on using GTONavy’s sequential tail lights at some point.

A vendor who I believe to be vintageleds.com, and goes by the handle on VMF of GTONavy stated that he developed side marker lights specifically for 70 Stangs. Here is his reply to my inquiry:

Quote:

Originally Posted by Mach1 Driver View Post

Interesting, so will it behave like a 70, or like a 69? That is, will the side markers still flash alternately with the turn signals?

The side marker will blink low to high brightness.

Thank you

Gary

[Machstang 0]

Hey Guys,

Looks like there is a lot of great info here.  Unfortunately, I am not an electrician so I am lost with these diagrams.  Do any of you know where there is a color version of the wiring schematics for a 70 mach 1.  I have several books but they are pretty useless.  I once ordered a CD from a vendor that claimed it contained all the color electrical schematics and vaccum schematics for the mustang but the CD didn't work.  Im lost right now as to how to fix some of the electrical gremlins in my mach.

thanks, bob 

[Rich Ackermann 174]

2 hours ago, Machstang said:

Hey Guys,

Looks like there is a lot of great info here.  Unfortunately, I am not an electrician so I am lost with these diagrams.  Do any of you know where there is a color version of the wiring schematics for a 70 mach 1.  I have several books but they are pretty useless.  I once ordered a CD from a vendor that claimed it contained all the color electrical schematics and vaccum schematics for the mustang but the CD didn't work.  Im lost right now as to how to fix some of the electrical gremlins in my mach.

thanks, bob 

I use the color diagram CD from a company call Forel publishing. They send you the installation CD with a license key. Worked fine on Windows 10. Also had to call or email them once and their support was very helpful.

Btw: I made the parking light mods to my front and rear harnesses to make them work in parallel like the 69s do and it worked great. I should mention i have only bench tested the electrical at the point.

[Machstang 0]

Thanks RIch, I think that is the same CD i got through one of the vendors.  Never could get it to work.  I even had a couple of techs from a computer company come over and the thing would just not load up.  I tried windows and apple.  I was hoping there was someone out there that sold a colored print (I've had  them for my BMWs, porsches, VW, and Chevys).  Just havent been able to find a full diagram for mustang.  Having the same problem with my cuda, but at least they sell the diagram, just not color keyed.

thanks,

[Machstang 0]

I found this on another site, but was wondering if they had something like this for a 1970 Mach 1.  Its pretty well done