Wiring Questions / Discussion

[451Mopar]

Lately been looking at different videos and posts on car wiring, and seeing all types of systems and opinions, but not much discussion on the pros and cons.

I am curios on your opinions of different aspects of car wiring. Here is four to start with:
Question #1 - Mostly relates to aftermarket wiring kits. To run wires directly from fuse block / dash harness direct to loads (lights, ignition, sensors, and such), or to break the wiring up into harnesses (rear / tailights, front/head lights, engine, and such).
Question #2 - Related to above the Stock / reproduction and American Autowire use a bulkhead connector where others like Hywire and Ron Francis run through a gromet. Takes on bulkhead connectors. This can be stock or aftermarket.
Question #3 - How much do you care about the wire type being used. Many of the real cheap Amazon harness are PVC insulated wiring as was most of the original wiring. Most reproduction and higher end aftermarket wiring is XLPE (TXL or GXL). Is anyone doing real high end stuff with ETFE (Tefzel) wire?
Question #4 - Opinions on using EPDM (welding) wire for battery relocation.

 

[493 Mike]

Lately been looking at different videos and posts on car wiring, and seeing all types of systems and opinions, but not much discussion on the pros and cons.

I am curios on your opinions of different aspects of car wiring. Here is four to start with:
Question #1 - Mostly relates to aftermarket wiring kits. To run wires directly from fuse block / dash harness direct to loads (lights, ignition, sensors, and such), or to break the wiring up into harnesses (rear / tailights, front/head lights, engine, and such).
Question #2 - Related to above the Stock / reproduction and American Autowire use a bulkhead connector where others like Hywire and Ron Francis run through a gromet. Takes on bulkhead connectors. This can be stock or aftermarket.
Question #3 - How much do you care about the wire type being used. Many of the real cheap Amazon harness are PVC insulated wiring as was most of the original wiring. Most reproduction and higher end aftermarket wiring is XLPE (TXL or GXL). Is anyone doing real high end stuff with ETFE (Tefzel) wire?
Question #4 - Opinions on using EPDM (welding) wire for battery relocation.

My answers do not refer to OEM restorations (much more advanced systems exist today).
#1: I like to build my own.
#2: The OEM bulkhead connector is fine with OEM electrical loads. With vastly increased loads, I would use a grommet.
#3: The better wire today should not have soy-based insulation. More strands=more flexibility (more cost usually).
#4: See #3.
Mike

 

[BeepBeepRR]

Everyone will have opinions but here are my thoughts.

1. OEM applications are plug and play for the most part and easy to get right the first time.
2. Aftermarket harnesses are great with the demand of newer electronics but, are a little daunting when it comes to making it work with existing sockets, gauges and various other issues.

 

[Doorkicker]

Lately been looking at different videos and posts on car wiring, and seeing all types of systems and opinions, but not much discussion on the pros and cons.

I am curios on your opinions of different aspects of car wiring. Here is four to start with:
Question #1 - Mostly relates to aftermarket wiring kits. To run wires directly from fuse block / dash harness direct to loads (lights, ignition, sensors, and such), or to break the wiring up into harnesses (rear / tailights, front/head lights, engine, and such).
Question #2 - Related to above the Stock / reproduction and American Autowire use a bulkhead connector where others like Hywire and Ron Francis run through a gromet. Takes on bulkhead connectors. This can be stock or aftermarket.
Question #3 - How much do you care about the wire type being used. Many of the real cheap Amazon harness are PVC insulated wiring as was most of the original wiring. Most reproduction and higher end aftermarket wiring is XLPE (TXL or GXL). Is anyone doing real high end stuff with ETFE (Tefzel) wire?
Question #4 - Opinions on using EPDM (welding) wire for battery relocation.

Just my $0.02...

---Question #1 - Mostly relates to aftermarket wiring kits. To run wires directly from fuse block / dash harness direct to loads (lights, ignition, sensors, and such), or to break the wiring up into harnesses (rear / tailights, front/head lights, engine, and such).

I make my own harnesses and will create them based on two things... first, and the most important, is the type of circuit, such as lights verses ignition, etc. and then second - far less important, but there - is section of the car, such as front, engine bay, cabin, and rear.

---Question #2 - Related to above the Stock / reproduction and American Autowire use a bulkhead connector where others like Hywire and Ron Francis run through a gromet. Takes on bulkhead connectors. This can be stock or aftermarket.

I try to use and rebuild the stock bulkhead connector whenever possible. I essentially pull it out, pull all the wires and blades, and start from scratch with new blades. And in many cases, I'll rewire them completely and remove circuits that are no longer used or now go through a relay.

---Question #3 - How much do you care about the wire type being used. Many of the real cheap Amazon harness are PVC insulated wiring as was most of the original wiring. Most reproduction and higher end aftermarket wiring is XLPE (TXL or GXL). Is anyone doing real high end stuff with ETFE (Tefzel) wire?

I'm less concerned about the insulation, but very focused on the type and style of wire. I focus on 100% pure, high strand copper. I know tin cladded coper is preferred for most. I avoid anything with aluminum.

---Question #4 - Opinions on using EPDM (welding) wire for battery relocation.

Definitely use EPDM, high strand copper for all high loads... especially batt. long hauls.

 

[gkent]

Battery cable ... DO NOT use "CCE" (copper coated aluminum) which is cheap and widely available on Amazon. Use "OFC" (oxygen free copper). Welding cable is the right stuff. And take note that it IS available in RED for + cables.

 

[radical rob]

I have used haywire on 3 cars.
Removed the bulkhead connector and welded in a patch panel. Don’t miss it as a potential problem at all.
Haywire kits come presectioned in groups like engine, dash, rear, headlights etc. fairly easy to keep straight.
Welding wire works fine. Agree with above, get the good copper wire.
For haywire Denny is your man. I have found him to be responsive, extremely knowledgeable, and very helpful when I had a question. They are not a big operation so when you call you will not get an ai voice. You’ll either get Denny or his wife. I have one more car to wire and I will be using them for that one as well.

 

[Xp29h]

When I did the complete rewire of my car, it was complete!

1. Brand new Ron Francis kit for everything! Brand new fuse box completely updated! New harnesses for everything! Front and rear everywhere!
2. My bulkhead connector was very sloppy and wires were loose and just removed it and build a grommet panel that covered the existing bulkhead hole and was all insulated so wires couldn’t chafe.
3. Part of the reason I chose the Ron Francis kit was the wire used at the time! They didn’t go cheap on that and I paid for it! But it’s been flawless so far! Don’t go cheap on wire!
4. I’ll leave to the folks that know more about that than me! Sorry can’t help ya!

Good luck!

This was the pile once I removed it all from the car!

 

[gkent]

Bulkhead connectors were great for assembly lines - subsystems like dashes, engines, etc. could be prewired and just plugged in as the vehicle progressed down the line. On custom cars they can be handy in that you don't have a huge, complete harness to contend with and, quite importantly, mistakes or modifications are easy. They're a personal choice.

 

[451Mopar]

Good information.
When a was reading about the EPDM welding cable it seems to have all the Pros:
Affordable
Flexible
high temp resistant
good abrasion resistance
good moisture and UV resistance
Cons:
Not good with oils, and fuels

I do see some wire advertised as chemical resistant EPDM? Not sure what is done to make it chemical resistant, but it seems when used it is routed away from chemicals unless connected directly to the starter.

I did make a starter cable using the EPDM wire, but put silicone jacketed fiberglass heat sleeve over the starter and solenoid wires.

Most of the time I try to use the XLPE insulated wire like TXL or GXL which is good against heat and chemicals. Although it is stranded, it is stiffer than the EPDM and silicone insulated wires. I think cost wise it might be about 10% more than PVC insulated wire?
Silicone insulated wire is flexible and good against heat and chemicals. I think the soft insulation might not be as abrasion resistant, and it costs more than the XLPE wire. I haven't looked closely at the cost comparisons of most of these wires. That might be interesting as I think the tefzel is multiple times the cost of other wires.

When I relocated the battery in the Charger, My brother-in-law, an electrician, gave me some glass braided silicone high temperature wire. I think it is SRML "motor lead" wire.
I haven't seen that used in other cars, likely because it is about $6 per foot for 1 AWG wire.

 

[493 Mike]

I want to add to my previous post that I purchased and used the Infinity Box system in my 65 build. Pricey but, what isn't? It was definitely a learning experience! The system work on grounds, completing circuits, instead of connecting the battery connector on, say the ignition switch, that terminal is connected to a ground. The computer (Master Cell) senses which switch is on and sends a signal (through a 2-wire buss to a Power Cell) which has fused connectors that run to say, tail lamps. It has lots of circuits to choose from and diagnostic LEDs to help pinpoint any abnormalities, if present. The use of a buss control cuts down on wire usage. It was an enjoyable experience to install-really making my pea brain strain!
Using grounds puts very little electrical load on switches and the furnished Master Cell wiring is only 20-22 gauge. Each Power Cell circuit is capable of 25 amp loads and they are programable for soft starts among other things.
Mike

 

[451Mopar]

Feel free to add more. I have seen the can bus type distributed power distribution modules, but never knew anyone who has used one.
Digging into all the options is quite a rabbit hole, but something I want to learn more about.
I do have a BS degree in Electronics Engineering (for real), but they don't get into all the real specific details of specifying wire standards and best practices.
Working in Aerospace, I worked with the really high end components, but way too expensive for most of us to use on our cars.

I think for most people who just want to get their wiring working for a stock/near stock vehicle, that the reproduction wiring harness are the best option although they seem expensive up front, you really save alot of time installing them as they are plug and play.
For many upgrades, there are work-arounds that work with the stock wiring harness too.

Custom wiring is another animal. Need to know your loads and wire lengths and even thermal environment to size the wire correctly (including de-rating) for current and voltage drop.
The Haltec, Motec, and other programable PDMs are interesting with the programable current limits (monitors current and uses electronics to stop over current , and electronic power outputs / no mechanical relays) and other options. These are expensive, more for race applications or where you want to view/log the current loads on multiple circuits.

I have used the Ron Francis wiring kit on a car with many custom changes. On that car I did retain the factory bulkhead connector (a new one), and a harness connector for the rear wiring harness sort of like original, although with several extra wires like fuel pump, trunk release, and such.

I have never done a really big audio system, just quad speakers with a trunk mounted sub.

Same for alarm systems, only have done fairly simple ones. Not the two way versions with remote start and such.

 

[gkent]

Just WHAT and HOW MUCH "chemicals" are you planning to use around your battery cables ?!?! In my humble opinion "heat" should be your main concern when it comes to the sleeving - and don't be fooled into thinking any kind of "heat wrap" is going to help! Standard welding cable insulation will be more than sufficient for a starter cable - just imagine what that stuff gets drapped through in the course of every day use in every kind of industry and environment !! Don't overthink it !!

 

[73MAG400]

You gentleman seem to have your finger on the pulse when is comes to electrical issues. I am putting together a 1971 Charger RT. I have no original wiring from the car. The dash was stripped so I am building it up from parts. I have a three /variable speed wiper switch. New H&M harness for a 1971 Charger with Rallye Dash. On the back of the wiper switch there are two combination connectors from the new harness however there is a single spade terminal at the top of the switch which there is no wire for from the new harness. Can anyone tell me what this terminal is for.

 

[Rebelrouser]

My answers do not refer to OEM restorations (much more advanced systems exist today).
#1: I like to build my own.
#2: The OEM bulkhead connector is fine with OEM electrical loads. With vastly increased loads, I would use a grommet.
#3: The better wire today should not have soy-based insulation. More strands=more flexibility (more cost usually).
#4: See #3.
Mike

I agree with you except for bulkhead connectors, what happens when you have to take the car apart for paint engine swap etc. unhooking and dragging all those wires c an be a pain. Especially since many kits and wire do not have as many colors as stock.

 

[451Mopar]

You gentleman seem to have your finger on the pulse when is comes to electrical issues. I am putting together a 1971 Charger RT. I have no original wiring from the car. The dash was stripped so I am building it up from parts. I have a three /variable speed wiper switch. New H&M harness for a 1971 Charger with Rallye Dash. On the back of the wiper switch there are two combination connectors from the new harness however there is a single spade terminal at the top of the switch which there is no wire for from the new harness. Can anyone tell me what this terminal is for.

View attachment 1957012

Do you already have the connection for the windshield washer?
I have a 1971 Factory service Manual, but I don't know where I put it.