Go to Electrical updates/upgrades List

[Mattax]

I haven't decided on much, a modest radio w/ 4 speakers using the built in amp(no external or subs), keeping the factory A/C and everything functional and safe mainly, I know before I took the car apart the headlights dimmed/brightened depending on engine rpm and a lot of things didn't work that should have. Much of the factory wiring looked a little small for the current that it was expected to handle too.

I don't know what you're starting with other than a year that factory AC was available so prob '66 or newer.
You could do an engine compartment auxilery fuse/relay box for the A/C, Headlights, and maybe the new radio. It would be best to know how much power it can draw. Then you can size wires. Also some stuff is more sensitive to electrical noice than other stuff. One advantage of sending power through the battery positive junction is reducing noise. Disadvantage is that it complicates protecting against major shorts and monitoring the battery charging.

Some websites that can help with wire sizing are in linked in this post
In fact that whole thread is probably worth your time.

As far as the factory loads and wires, for the distance and time in use, they were generally adequate. Not much is really a high load. Headlights were # 6012 sealed beams until about '73. That's one of the more marginal circuits especially with the 6014 headlamps.
Battery recharging can be a high load, but for a short time the wires can take it. That's the main use of the ammeter - monitoring the load.
AC and heater blower on high are also can be over 10 amps, but OK for the normal length of time needed at high.
As mentioned, the factory did have heavy duty wiring options for high loads.
On the other hand they also added weakpoints at times. The connector at the steering column for '70-74 cars in particular and the engine connectors around '73 -'75? come to mind.

The weak points I see in repairs and mods tend to be poorly crimped or soldered connections, poorly supported and non-heat/oil resistant wires in the engine bay. If you're starting from scratch, there's probably some places you'ld want to use connectors with better sealing and more contact area than the old 1/4" and 5/16" push-on types. But the Packard series are adequate if properly made.

 

[pyrogen007]

I have a 70 Dart Swinger that I am swapping from a slant 6/auto to a 383/4 speed, car originally had points ignition, manual washer fluid pump, not sure which wiper motor/switch, A/C, manual brakes and power steering, I think it came with a AM radio and 1 speaker, dome light and I think that's about it.

I am def keeping my A/C want to keep power steering and might upgrade to power brakes at some point if it fits without being too hard to work on. I'd like to upgrade to the electric washer pump and 3speed wipers unless I can find a suitable wiper delay solution. I might go to electric fans, electronic ignition, trying to decide if I do, when.

 

[MadScientistMat]

Rusty, aren't you running an electronic ignition?

The biggest threat to reliability isn't anything the factory did - it's previous owners. So first fix any wiring that involves lamp cord, wire nuts, Scotchlock connectors, or similar abominations.

Next priority is to make sure you don't become "that" previous owner. If your own wiring skills aren't that great, stick with easy plug and play options. Pertonix Ignitor 1 instead of points, drop in solid state conversions for points type voltage regulators and instrument panel voltage limiters. And you can wait until parts break to make this fix. An ammeter bypass isn't too hard either, but I'm not sure it's mandatory either. But you will want a volt meter if you do the bypass. Don't stay in the dark about your charging system.

Some things that are nice to have but may take more skill level:

For a headlight upgrade, the Toyota kit if you're on a budget, a personal recommendation from @slantsixdan if you aren't.

A third brake light isn't a bad idea.

If you can hear it over your exhaust, a stereo upgrade is great for a driver. There's even a few you can disguise as the stock radio.

More gauges if you don't already have them in the stock dash.

My project has a lot more, of course, with an EFI system, trunk mounted battery, and electric fans, but that's not for everyone.

But the big one is to avoid hack jobs.

 

[pyrogen007]

I was an aircraft electrician for a while and still regularly splice/crimp/solder in my current role so I am pretty confident in my abilities to correctly route and terminate wires, in fact, I'm actually kind of looking forward to this part waaaaay more than all the rust removal/painting I'm currently doing on my car. I am just trying to get out in front on the planning and decision making and if these discussions can help someone else with their project then even better!

I hadn't really thought of the third brake light to be honest!

My factory cluster is a mess so I still have to decide what I'm doing with that. I know I want at min these gauges: volts, speed, rpm, water temp, oil pressure. Considering vacuum, oil temp and air/fuel.

I'm hoping I have enough room for a clutch fan on the B engine but am not averse to running OEM electric fans from a donor car, I saw a few threads detailing that process.

I really want to drive this car a lot with my family so I am trying to take my time and do it right. There are only 2 ways to do anything, right and again.

 

[crackedback]

Anything you can do to remove load from the factory harness is a good thing. Relays work on a lot of items and likely won't tax the bulkhead/charge circuit when the car is running. With these cars and the way the OEM charging system is wired, there is no perfect place to pull power for all operating/non-operating conditions.

Headlights, AC compressor, power windows, power top pump, fuel pumps, fans, blower motor (high setting) all benefit from clean power off the OEM path.

Don't use junk products, Tyco/Bosch/TE relays only, no chinese stuff. Failure rates on Chinese relays is not great. The good TE relays for a headlight setup from Moser are about $14 each now. I sell the component relay kits without wire for the self build type too.

#1 deal, get an alternator with sufficient output to power everything at idle.

 

[matthon]

tiny fuse panel

And the Napa solid state flashers for that modern defined click!

 

[slantsixdan]

If you weren't constrained to keep it 100% factory correct, and intended to drive your old Mopar daily(within reason), what electrical/ignition updates/upgrades would you chose?

Going beyond just electrics, lookit this thread.

Headlight wire upsize/add relays - safety

Yes. Crucial to choose components carefully, in accord with reality (not advertising babble or clickbait); there's a ton of junk on the market.

Ammeter bypass/voltage gauge swap - safety/reliability

Here again: done properly (avoid the halfassed nonsense from the dopes at MadElectrical).

Electronic ignition conversion - lower maintenance/convenience?

HEI upgrade

What else y'all have on your list?

Central brake light.

More and better circuit protection, especially on the pre-'65 cars, and REALLY especially on the pre-'63 cars.

 

[RustyRatRod]

Rusty, aren't you running an electronic ignition?

The biggest threat to reliability isn't anything the factory did - it's previous owners. So first fix any wiring that involves lamp cord, wire nuts, Scotchlock connectors, or similar abominations.

Next priority is to make sure you don't become "that" previous owner. If your own wiring skills aren't that great, stick with easy plug and play options. Pertonix Ignitor 1 instead of points, drop in solid state conversions for points type voltage regulators and instrument panel voltage limiters. And you can wait until parts break to make this fix. An ammeter bypass isn't too hard either, but I'm not sure it's mandatory either. But you will want a volt meter if you do the bypass. Don't stay in the dark about your charging system.

Some things that are nice to have but may take more skill level:

For a headlight upgrade, the Toyota kit if you're on a budget, a personal recommendation from @slantsixdan if you aren't.

A third brake light isn't a bad idea.

If you can hear it over your exhaust, a stereo upgrade is great for a driver. There's even a few you can disguise as the stock radio.

More gauges if you don't already have them in the stock dash.

My project has a lot more, of course, with an EFI system, trunk mounted battery, and electric fans, but that's not for everyone.

But the big one is to avoid hack jobs.

Yes sir. All week long and twice on Sunday. Stock Chrysler style. Low amp draw.

 

[DartGTDan]

I've done the 3 you listed.

I'm considering doing this modification as well (from a FABO member (I forget his user name)):

 

[matthon]

More and better circuit protection, especially on the pre-'65 cars, and REALLY especially on the pre-'63 cars.

On my 62 I ditched a really nice complete harness because after all I'm apparently not that dumb.

Bought the most inexpensive AAW generic kit, used the original plastic plugs and bought new original style connectors.

I still have a ton of wire leftover from that kit.

 

[Clelan]

In my car the best electrical upgrades so far, are mini starter, 100a 1 wire alternator, volt meter instead of amp meter, electric in tank Fuel pump, head light relays, separate under hood fuse/relay panel for constant power loads, small underdash additional fuse panel for keyed power loads. I first restored my wiring harness, and then thoughtfully modified it to suit my needs.

Cley

 

[rwilson]

I isolated the field/regulator from the ignition run circuit and placed it on it's own relay powered circuit (relay triggered by the original field feed). It works great.

I isolated the field/regulator from the ignition run circuit and placed it on its own relay powered circuit (relay triggered by the original field feed). It works great.

CFD244 -what is the purpose/benefit of this modification?

 

[MadScientistMat]

That mod delivers a more accurate voltage reading to the voltage regulator and can help prevent overcharging.

 

[CFD244]

CFD244 -what is the purpose/benefit of this modification?

My charge voltage was a little higher (14.8v) than I'd like due to minor voltage drop in the ignition 1 circuit. This corrected that issue without putting the ignition circuit on a relay. @67Dart273 has been a proponent of this for years.....and, he knows his ****.

 

[rwilson]

My charge voltage was a little higher (14.8v) than I'd like due to minor voltage drop in the ignition 1 circuit. This corrected that issue without putting the ignition circuit on a relay. @67Dart273 has been a proponent of this for years.....and, he knows his ****.

Thanks

 

[harrisonm]

I have a 69 Barracuda with a 340 built to about 375HP. I upgraded my ignition to a complete MSD system. I got the non-vacuum advance distributor, the MSD box, an MSD coil and MSD plug wires. I am VERY happy with the system. The car starts easier and idles better.

 

[matthon]

If you have efi, timing control.

 

[Woody500]

Mine is out of the car for the same reason, its brittle and falling apart but also looks like there might have been some amateur repairs at some point, I don't trust it, but it will make a good reference/starting point for a rewire.

Adding relays to major circuits does seem like a good idea in general, good call!

Some guys still using ND oil, too!

 

[mderoy340]

Interior fan on relays saves the fan switch contacts from frying.

 

[Dave999]

hazard/emergency flashers on cars without....
branded good quality country specific halogen headlamps and relays if not standard.
at a push a 40 amp denso...easier for me to get than a mopar alternator
with a mopar alternator do the police/HD update that relay controls the power into the regulator as a direct feed form battery
mini starter (denso again)
HEI with appropriate coil
strip and re insulate your ammeter studs fibre washers etc and make sure to lock glue, spikey lock washer the bolt on cables.
clean all grounds
clean all fuses and fuse holders

leave the rest alone, its the last 6 inches of each wire and its connector that causes the problem. under the wrap, the loom, if not burnt or hacked about, will be pretty much the same as it was on day one

Dave

 

[Walkstep]

Nice question.

Got me to write out all of the upgrades for my 1968 Dodge Dart GTS 383 resto/stealth mod.

It's long but here you go:

Wiring Upgrades –Supply Side

Relocate battery to passenger side of trunk

Installed 4-terminal 300 amp bus bar on firewall

Installed 2/0 SGX cable from bus bar to battery

Ground battery to trunk seam sheet metal below trunk lid hinge with 2/0 SGX cable - black

Installed single post auxiliary ground terminal next to next to bus bar on firewall

Installed 4 AWG SGX cable from auxiliary ground terminal to battery

Installed 110 amp single-wire alternator

Installed a Busman 125-amp circuit breaker for alternator on firewall in lieu of fusible link

Wired alternator positive to Busman and then to bus bar with 4 AWG SGX cable - black

Wired alternator negative to auxiliary ground terminal 6 AWG SGT cable – black, to supplement ground through engine and chassis

Grounded driver front of engine block (low) with 2/0 AWG to adjacent subframe with existing bolts

Grounded engine from rear passenger side head existing bolt hole to firewall with 10 AWG – black, with correct Mopar connectors to emulate the stock Mopar ground



Wiring Upgrades –Demand Side

Wired mini starter load to bus with 2 AWG GSX cable – red

Installed new starter relay in original position at battery location in engine compartment

Connected radiator PWM fan controller direct to bus and ground with TXL wire and fusible link

Deleted, bypassed or repurposed all stock ignition wiring

MSD-6AL connected to battery bus and ground terminal

Added a 6-circuit enclosed relay and fuse box in the engine compartment for high/low headlights and other circuits auxiliary to the stock harness

Installed a reproduction engine compartment harness but modified it for the headlight relay upgrade detailed in many forums

Installed Koito halogen headlights with ceramic connectors

Custom 3-button under dash switch panel with two color (on/off) LED lighting for line-lock, fuel pump and oil accumulator

Retro Sound reproduction radio powered from the original harness connector and battery

DS18 stereo amplifier powered directly from the battery mounted in the trunk on the slope behind the back seat with inline fuse

DS18 powered subwoofer mounted flat in trunk behind back seat and wired to battery with inline fuse

Added Innovate 3-gauge cluster above center console for oil, water temp, voltage, duel air/fuel ratio (right and left), and data acquisition. These each require their own circuit with the correct rated fuses.

Wired Battery Tender cable harness to battery


Wiring Upgrades –General Notes

All connections 8 AWG and larger were hydraulically crimped

All connections 10 AWG and smaller were hand crimped with correct tool (practice and test first)

Crimped and soldered a few connections early on but moved away from solder after more research (except for speakers)

Used marine grade heat shrink on most connections for corrosion resistance and strain relief

Used Painless Classic Braid wire loom extensively for wire protection and a clean vintage look

Used correctly sized Deutsch connectors when connectors were needed for new circuits

Photocopy wire schematics from factory manual to use while you’re in the car, and for design and modification

Schematics drawn (by hand) for all mods and non-stock circuits

All non-stock wiring labeled using a Brother label printer with black label tape, often both ends of the wire

Removed any previous electrical mods as I replaced or eliminated those circuits

Checked all existing wires for cuts and abrasions

Replaced firewall bulkhead connector and each interior-side connector with correct Packard 58 terminals

Tested circuits as I installed them


There are probably a few I forgot. The car has high horsepower, I want it to run reliably and be easier to repair if needed. And I like doing this

 

[pyrogen007]

Heck yeah, thank you! Thank you to everyone that responded! Lots of great information. Hopefully this helps others as well.

 

[red67gts]

Along with a lot of the suggestions above I eliminated the bulkhead connectors by cutting a heavy rubber belting to fit and drilled out the original connectors and ran wires straight through as this is where most of wiring fires start. Ask me how I know. All my connections used the aluminum crimps and soldered. My neighbor used some SolderSeal connectors on my dozier fan. I was impressed with them and bought a kit but haven't had a chance to use myself. You may want to check them out. They have low temp solder and shrink wrap combined, Joe

 

[pyrogen007]

I have thought about whether to retain a bulkhead connector or do a sealed feed through. I see the benefits of both and if I retain the bulkhead connector all the contacts/wires will be new and the high amp circuits will be removed and only "signal" wires that energize relays will be retained, that should remove most of the chance of fire but all points of connection are a potential point of failure too.