small wiring mystery

I have 3 1970 Darts. The wiring is pretty stock on all of them. I've been replacing all the harnesses on #3 and wanted to add the subharness for an interior light package while I was doing it. As a reference, I pulled down some of the under dash wiring from #2 to see just how it was put together (#2 only as 70,000 miles on it and has an original unmolested dash wiring harness), In doing so I came across the odd little harness shown here:



It plugs ino the place where the turn signal flasher usually just plugs right into the harness and its purpose is to add an inline 14 amp fuse. I have never seen this and it does not exist on any one the other Darts or on two reference harnesses that I have from other 70 Darts. The flasher is a whopper and it says the following right on the flasher:



I can't figure out what the purpose of this arrangement might be, but it is obviously factory, down to the paper tag on the fuse holder:



I made a needed repair (one of the fuse holder wires broke off right where it went into the fuse holder) and everything works fine now. The only thing different about the turn signals on #2 - the one with the added fuse, is that it has fender mounted turn signal indicators, but when I look at the bitty bulbs in them, I think that that can't add much of a draw. This little harness does not show in any of the FSM schematics. Anybody have any idea why this is made this way? Why would I need this HEAVY DUTY!!! flasher. If I wanted to add fender mounted turn signal indicators on one of the other darts should I add a fuse and heavy duty flasher?

My bet is it would be a towing package add on.

Nope, I bought this one in 1983 from a classic little old lady in Tennessee - It had never been out of the county where it was sold and had 27,000 on the clock. I've had it ever since, no towing. Sensible guess if it was lighting an extra set of urn signal lights on the trailer.

Found this. 14th line .

67 dart had at best 1 front turn signal light and a small fender mounted turn indicator, and a rear. 68 up had 1 front 1 side, maybe 1 fender top and 1 rear side and 1 rear turn signal

So 67 = 2 bulbs plus a fender top
68 up = 4 bulbs plus a fender top

Not a lot of current but maybe twice as much as 67.

Still thinking was part of a trailer towing package.

Do you by chance have the build sheet? I haven't disassemble mine that far, but I have the light group and interior lights(A11,A12,) and a rear trunk interior release switch. This has always been a mystery to me, as I never found any factory trunk release option. It has a big switch under the dash on the left side, and the mechanical tailshaft in the trunk lock has been shortened so the key switch won't operate the trunk lock. I assumed this was a dealer or aftermarket modification. I'll look under the dash for something similar to yours. Paul.

I checked for recals of 1970 darts there were 3 none related to turn signals.

67 has 6!

Maybe an oddball built car in CANADA!???? Ya know how strange the Canutes can be!? No offence to our Northern brothers!!!

1970 was a bit of first year run for some of the electrical, but not all of it. The larger fuse box with more fuses didn't appear before when, 1973 maybe?
I did a little research. From what I gather, that inline fuse is added circuit protection. 1970 only, Charger, Roadrunner, Dart too apparently. They may have simply enlarged a wire size in the next year model, or they might have even done that during the 1970 model run. So look at your fuse box. Is there a turn signal fuse? I don't think so. Look wiring diagram. Where did signal power come from? In some cities with heavy traffic a driver could sit with left turn signal on for quite a while. Who knows what number of instances appeared. Not enough for a recall.
Back when I worked for Ford, the Mustang, Thunderbird, Escort, could have fog lamps. Those owners that used them only in fog didn't have a problem. The few that wanted to run the fog lamps all the dang time cooked the wiring and the multi function switch in the steering column. Never was a recall. So your fuse holder might have been dealer installed after a fault occurred.

Nope, my 70 duster had the same thing under the dash. I Thought it was a band aid fix to a bigger wiring problem but I did a little more research and it seems stock. I just bypassed it since it already has a fuse in the fuse block.

!!!HUH!!! LOLOL "My" correct answer is "I don't know." Obviously "Ma" thought the fuse was needed or they would not have done so

Thanks for all the info - somewhere in there is the correct answer. I'll keep it that way it came, but I was thinking of adding fendertop indicators on my current 70 GT project and am now trying to figure out if I should add a fuse if I do. Does anybody have one of these little wiring harnesses on a scrap harness they have for parts? I'll be looking for the plastic connection covers and the fuse holder - wires don't matter.

barbee6043 said:

Maybe an oddball built car in CANADA!???? Ya know how strange the Canutes can be!? No offence to our Northern brothers!!!

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I believe that the vast majority of 1970 Darts were made in Canada (anybody have figures?) even the majority of those sold in the US. I always thought this was funny because the Dart was always seen as an All American family car and most of them weren't even made here. I think that next time I go to an all makes and models show I'll enter one of my Darts in the "import" category. (and I believe that's "Canucks" not 'Canutes')

I believe all the '70 Swinger 340's were made in Windsor. I know mine was, as I have the build sheet. You could tee off a golf ball and hit American soil, but it was still built in Canada. LM23HORXXXXXX, I believe the R designates it as being built in Windsor. Anyone with more knowledge, please feel free to correct me.

70dart340 said:

I believe the R designates it as being built in Windsor.

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That would mean that all three of mine - A Custom, A Swinger and a GT, were all built in Canada

I have read unsubstantiated rumors that the Canadian cars had heavier gauge sheet metal, and more seal on the body joints. I don't think it's true, but when I had to remove the LF fender, it was sealed good. Never leaked, even after 51 years.

str12-340 said:

That would mean that all three of mine - A Custom, A Swinger and a GT, were all built in Canada

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If the 7th digit is an "R", that's the Windsor factory.