1970 Dart matching numbers 340 4 Speed

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F/A Tech

F/A Tech

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The back up lights come on but the dash"reverse" light doesn't . Where does it get power from?
the electrical diagram show it from bulkhead disconnect "C" is that the only connection on "C" or does it go from there to rear lights ? Thanks
 
Couple of suggestions:

1. I would modify the title of the thread, looks like you started an WIW thread or something. Make it more specific.

2. Might try posting the question in the Electrical and Ignition forum - Electrical and Ignition

As to your question:

Not sure if your car is like my 1974, but mine get's power from a lead in the reverse light circuit that heads down to the plug on the transmission. Wire goes through a grommet in the firewall up at the top and is a single wire to the light which is grounded through the dash frame.

Might follow the wire from the light and make sure it passes through the firewall and is plugged into the harness that heads down to the switch on the trans.
 
F/A Tech said:
The back up lights come on but the dash"reverse" light doesn't . Where does it get power from?
Click to expand...
4 speed car. work backwards on the diagrams.
upload_2021-4-12_14-32-11.png


Z in the engine compartment goes to wire B2B

So it gets the power from B2 when the switch is closed.
upload_2021-4-12_14-37-56.png


Since the reverse lights work, either the bulb is out or not connected or grounded.


the electrical diagram show it from bulkhead disconnect "C" is that the only connection on "C" or does it go from there to rear lights ? Thanks
Click to expand...
Not sure what you're asking here.
Inside the car B2 goes to the boddy hanress connector.
B1 connects to X12 which comes from the fusebox.
 
Make life easy on yourself, trace or copy just the circuit wires of interest.
upload_2021-4-12_14-48-9.png


upload_2021-4-12_14-52-30.png
 
Mattax said:
Make life easy on yourself, trace or copy just the circuit wires of interest.
View attachment 1715722564

View attachment 1715722566
Click to expand...

Interesting. So some years it was routed through the bulkhead connector instead of separate.

Wonder if it was because in '74 they were running out of holes in the bulkhead connector. More likely it was because the auto and 4 speed main dash harness would be the same.
 
I don't know. There seems to be quite a variety of circuits that got run through grommets depending on the year. 1967 had the tachometer wire added to the main harness and used the bulkhead connector. 1968 and '69 ran the tach wire through a grommet. There's many more examples like your talking about in the mid '70s. In this post Keith was comparing '74 to '75.

I'm going to guess the decision on which wires to route through a grommet came during production engineering. Production would project which options would be the least volume and easiest to add by using a grommet. They might have also decided grommet routing would be easier vs. having an unused wire occupying the standard harness bundle.

Exception to this might be items that the design team specifically called out as preferable to use a grommet because of the wire size or high loads. But even there, those were less common options...
 
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1970 Dodge Dart Challenger Service Manual downloaded from mymopar.com
 
You may or may not know there is a sensor in the trans also. I remember having to fix my connection at the bulkhead connector. I have a 70 dart swinger. Its funny right now that wiring harness is on the bench, I am going over it once again, I may replace all the wires. That particular harness takes a beating for some reason.( And it is 50 years old LOL!)
 
Dartswinger70 said:
You may or may not know there is a sensor in the trans also. I remember having to fix my connection at the bulkhead connector. I have a 70 dart swinger. Its funny right now that wiring harness is on the bench, I am going over it once again, I may replace all the wires. That particular harness takes a beating for some reason.( And it is 50 years old LOL!)
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I bought my '70 Duster 340 last November and immediately started looking things over. Had a lot of little electrical gremlins. The under dash wiring harness was in poor shape and had been hacked up, so I ended up getting a new repop. While the instrument cluster was out, I also replaced the two circuit boards in the rallye dash because some of the pins were bad. Lots of work, but all is happy now. The wiring in those old harnesses get brittle, corroded by moisture from leaks, and people hacking. Was so nice to be able to plug in fresh connectors and have everything work again!
 
Ricks70Duster340 said:
I bought my '70 Duster 340 last November and immediately started looking things over. Had a lot of little electrical gremlins. The under dash wiring harness was in poor shape and had been hacked up, so I ended up getting a new repop. While the instrument cluster was out, I also replaced the two circuit boards in the rallye dash because some of the pins were bad. Lots of work, but all is happy now. The wiring in those old harnesses get brittle, corroded by moisture from leaks, and people hacking. Was so nice to be able to plug in fresh connectors and have everything work again!
Click to expand...
What repop harness did you get? I have the underhood ,but the under dahs and the one on the engine bay side that goes to the wiper motor and the trans reverse sensor I need. Do they repep those? the last I knew they didnt...
 
Dartswinger70 said:
What repop harness did you get? I have the underhood ,but the under dahs and the one on the engine bay side that goes to the wiper motor and the trans reverse sensor I need. Do they repep those? the last I knew they didnt...
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I got this: MA2316 - 1970 Mopar A-Body w/ Rallye Gauges Under Dash Wire Harness

Don't see the one for the wiper motor or reverse sensor. I made the mistake of ordering the standard wiring harness first. As I was installing it, I found out it was not the rallye one, so I had to order the correct rallye one. Since it was electrical, no refunds. Ate a lot on that mistake, but have a new harness (MA2315) for a non-rallye '70 Duster if anyone needs it!
 
Ricks70Duster340 said:
I got this: MA2316 - 1970 Mopar A-Body w/ Rallye Gauges Under Dash Wire Harness

Don't see the one for the wiper motor or reverse sensor. I made the mistake of ordering the standard wiring harness first. As I was installing it, I found out it was not the rallye one, so I had to order the correct rallye one. Since it was electrical, no refunds. Ate a lot on that mistake, but have a new harness (MA2315) for a non-rallye '70 Duster if anyone needs it!
Click to expand...
That may solve some of my problems thanks for the info. i dont recall an underdash rally harness availble years ago.
 
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