Upgrading the electrical system in our 67 Newport Custom

[Norwegianmopar]

Since we are redoing the interior we also want to upgrade all the old wiring etc while at it. I have been looking at complete kits like this from Painless:

21 Circuit Customizable 1966-76 Mopar Chassis Harness Part No 10127

Has anyone here any experience with this kit, or is there better solutions out there? We want to replace every wire and cable on the car.

 

[Big_John]

Most of those are downgrades, not upgrades and I would say that kit is a downgrade.

 

[CBODY67]

Other than the ammeter bypass (threads on that in this forum), what is the concern, other than age?

When Painless started out, their main advantage was that unlike most of the other street rod harnesses available at the time, they used OEM-grade Packard Electric (the wire, not the car) wiring and terminals. At the time, nobody else was doing that. In those earlier times, even with the '55-'57 Chevy vehicles, some wiring harness suppliers sold harnesses with the correct color codes, BUT had thinner and shinier insulation on the copper wires. Theoretically correct, but not nearly as substantial or robust as the OEM harness it was replacing.

Understand, too, that most of their kits are universal in nature, not "specific-fit" oriented. I suspect they are using non-glass, later-model style fuses, too. It might also be that some wiring pieces (like the tail light harness provided) might need some extensions for a longer car as a Chrysler. What light sockets do you propose to use with the new wiring?

Just some thoughts,
CBODY67

 

[Norwegianmopar]

Most of those are downgrades, not upgrades and I would say that kit is a downgrade.

What would you recommend instead and where to buy?

 

[Norwegianmopar]

Other than the ammeter bypass (threads on that in this forum), what is the concern, other than age?

When Painless started out, their main advantage was that unlike most of the other street rod harnesses available at the time, they used OEM-grade Packard Electric (the wire, not the car) wiring and terminals. At the time, nobody else was doing that. In those earlier times, even with the '55-'57 Chevy vehicles, some wiring harness suppliers sold harnesses with the correct color codes, BUT had thinner and shinier insulation on the copper wires. Theoretically correct, but not nearly as substantial or robust as the OEM harness it was replacing.

Understand, too, that most of their kits are universal in nature, not "specific-fit" oriented. I suspect they are using non-glass, later-model style fuses, too. It might also be that some wiring pieces (like the tail light harness provided) might need some extensions for a longer car as a Chrysler. What light sockets do you propose to use with the new wiring?

Just some thoughts,
CBODY67

It's mostly age and somewhat messy clusters of wire here and there. Want to have everything top notch and safe in the long run. There are some gremlins which we want to remove, like only having high beams on all headlights or no light at all, the left side fender mounted turn signal indicator comes on while braking etc. We also want to tidy up the engine compartment with new hoses and cables as well as cleaning and painting components. Want everything to match the clean exterior and sound mechanicals.

 

[Big_John]

What would you recommend instead and where to buy?

Evans Wiring Harnesses should have the under-hood harness and maybe some more.

What I've done with other cars is lay the existing wiring out on a piece of plywood and laid out the "pattern" with headless finishing nails. Then unwrap and change one wire at a time and rewrap it with harness tape (has no adhesive) Rhode Island Wiring Service Inc. has a lot of the terminals and good wire sold by the foot. For that matter, I think if you sent them a harness they could copy it.

Here's a pic of how I do my harnesses. This is the exact same way they make harnesses for aircraft etc. I have seen it in person in defense factories.

 

[3175375]

It's mostly age and somewhat messy clusters of wire here and there. Want to have everything top notch and safe in the long run. There are some gremlins which we want to remove, like only having high beams on all headlights or no light at all, the left side fender mounted turn signal indicator comes on while braking etc. We also want to tidy up the engine compartment with new hoses and cables as well as cleaning and painting components. Want everything to match the clean exterior and sound mechanicals.

View attachment 671608

The problems that you cite are correctable without ripping out the existing wiring.
I also am concerned that you might be getting into a lot to end up with the functionality that the original design provided.

You might want to consider actually fixing the existing wiring. You would be happy and better off in the end.

 

[Norwegianmopar]

The problems that you cite are correctable without ripping out the existing wiring.
I also am concerned that you might be getting into a lot to end up with the functionality that the original design provided.

You might want to consider actually fixing the existing wiring. You would be happy and better off in the end.

Fixing the existing wiring is an option, but surely there must be kits or harnesses one can buy instead of changing one by one wire, like say an under dash kit, engine bay kit, one for the lights and so on?

 

[3175375]

Fixing the existing wiring is an option, but surely there must be kits or harnesses one can buy instead of changing one by one wire, like say an under dash kit, engine bay kit, one for the lights and so on?

I don’t believe that there’s a silver bullet solution for our vehicles.

 

[66polara]

I installed a painless kit on my 66 polara, not sure if I would do it again. Not that the product wasn't good, but you are now taking the wiring diagram from your service manual and throwing it away. If I was to do it again I'd probably just replace the old wiring with new same color and size. Keeps it much closer to stock, but it's also a great time to upgrade all lighting.

 

[66polara]

Evans Wiring Harnesses should have the under-hood harness and maybe some more.

What I've done with other cars is lay the existing wiring out on a piece of plywood and laid out the "pattern" with headless finishing nails. Then unwrap and change one wire at a time and rewrap it with harness tape (has no adhesive) Rhode Island Wiring Service Inc. has a lot of the terminals and good wire sold by the foot. For that matter, I think if you sent them a harness they could copy it.

Here's a pic of how I do my harnesses. This is the exact same way they make harnesses for aircraft etc. I have seen it in person in defense factories.

View attachment 671609

When you use this method, which seems very good, do u still utilize the firewall milti pin connectors?

 

[Big_John]

When you use this method, which seems very good, do u still utilize the firewall milti pin connectors?

That particular harness was for a '53 Chrysler, so there wasn't a bulkhead connector like we have in 60's-70's cars.

If I was doing one for a later car, I would use the bulkhead connector. IMHO, the bulkhead connector doesn't cause any problems as long as the connectors are clean and tight and you aren't trying to overload any of the circuits.

Really, the only connector I see having big problems is the connector under the steering column after they went to the ignition key on the column. The red feed wire always seems to be burnt and melted.

 

[66polara]

That particular harness was for a '53 Chrysler, so there wasn't a bulkhead connector like we have in 60's-70's cars.

If I was doing one for a later car, I would use the bulkhead connector. IMHO, the bulkhead connector doesn't cause any problems as long as the connectors are clean and tight and you aren't trying to overload any of the circuits.

Really, the only connector I see having big problems is the connector under the steering column after they went to the ignition key on the column. The red feed wire always seems to be burnt and melted.

Yes that one was bad in my connector but some others were too. I agree w you, if the connection is new and tight w some conductive lube it should be fine.

 

[66polara]

Yes that one was bad in my connector but some others were too. I agree w you, if the connection is new and tight w some conductive lube it should be fine.

It was a fun job though, beats hell outa watching tv

 

[Big_John]

w some conductive lube it should be fine.

Well... If you mean dielectric grease, it's not conductive. It's an insulating grease that the connector pushes through. I don't lie to use it on connectors, although on the insulators, I think it's fine.

Cue @Trace 300 Hurst making some sort of comment... I think he used to drive a train...

 

[MoPar~Man]

You can buy new pins and sockets for the bulkhead connector. I did that just recently, haven't put them in yet. You probably have a bad ground to the headlights. Running more ground wires from various body locations back to the battery would probably solve your problem. A dedicated ground wire from the voltage regulator is I think a good idea. Adding a dedicated ground wire to the gas tank sending unit is something I do, the original factory method of grounding the sending unit is flaky.

 

[Trace 300 Hurst]

Well... If you mean dielectric grease, it's not conductive. It's an insulating grease that the connector pushes through. I don't lie to use it on connectors, although on the insulators, I think it's fine.

Cue @Trace 300 Hurst making some sort of comment... I think he used to drive a train...

Steam train. No electrical connectors needing corrosion-preventative dielectric grease!

 

[live4theking]

Evans Wiring Harnesses should have the under-hood harness and maybe some more.

What I've done with other cars is lay the existing wiring out on a piece of plywood and laid out the "pattern" with headless finishing nails. Then unwrap and change one wire at a time and rewrap it with harness tape (has no adhesive) Rhode Island Wiring Service Inc. has a lot of the terminals and good wire sold by the foot. For that matter, I think if you sent them a harness they could copy it.

Here's a pic of how I do my harnesses. This is the exact same way they make harnesses for aircraft etc. I have seen it in person in defense factories.

View attachment 671609

Unfortunately, like the others said there are no harnesses made specially for our C bodies. You maybe able to get a underhood harness from Evans. I bought a set of male and female connector from them so I could unplug my taillight harness and insert a harness so that I could light up my hitch hauler. If I was going to take on a whole harness I'd do it Big_John's way. Show and stay wins the race.

 

[66polara]

You can buy new pins and sockets for the bulkhead connector. I did that just recently, haven't put them in yet. You probably have a bad ground to the headlights. Running more ground wires from various body locations back to the battery would probably solve your problem. A dedicated ground wire from the voltage regulator is I think a good idea. Adding a dedicated ground wire to the gas tank sending unit is something I do, the original factory method of grounding the sending unit is flaky.

How did you ground the gas tank sending unit? I know there are probably threads regarding that but I'm wondering what you did

 

[66polara]

Steam train. No electrical connectors needing corrosion-preventative dielectric grease!

So a point of clarification, conductive lube was incorrect but I couldn't remember dielectric grease. Some of the fellas call it different names, but I've used dielectric grease on any connection that was subject to moisture or corrosion for years. We had a maintenance engineer back in the day that insisted on it where it was felt to be necessary, so when I started working on my '66 it seemed to be a no brainer. After looking around at some threads it seems this is a bit of a topic as to whether it works or not, I think it's a matter of preference but I can say I have never seen a breakdown of conductors or terminations that was caused by this being used.