[64speed]

I originally wanted to run all M&H repro harnesses but the cost for the whole car is unreal. It's not off the table as an option but I have been looking more at the aftermarket kits like American autowire and painless wiring. I want to use all my original switches which it doesn't look like you can do with some of these kits. Which kit is the best most comprehensive kit out there that won't leave me scratching my head for three months?

[HWYSTR455]

Unless you are ready to do customization, those types of kits are not for you. And if you want it to look good, you have to be fairly good with customization.

Almost all the kits serve multiple years, and you have to pick and choose the connectors, etc and install the ones that fit your app. I am in the middle of an AWW install, it's a custom install, and on just the dash harness, I have like 40 hours in it, and probably have another 20 hours to go.

There are alternatives to M&H, but most are competitively priced, so there's no real gain/savings.

Dash harnesses are the most expensive, but are usually the ones that are the most hacked up. You can remove it, lay it on a table, and replace what areas are damaged, then re-wrap. It still won't be as clean as a replacement one, but you will save money.

It's much easier to just pull a dash harness out of the box, and replace the existing one. All the ends/connectors are pretty much a fall-in-place hook up.

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[gassman_67]

Originally Posted by HWYSTR455

Unless you are ready to do customization, those types of kits are not for you. And if you want it to look good, you have to be fairly good with customization.

Almost all the kits serve multiple years, and you have to pick and choose the connectors, etc and install the ones that fit your app. I am in the middle of an AWW install, it's a custom install, and on just the dash harness, I have like 40 hours in it, and probably have another 20 hours to go.

There are alternatives to M&H, but most are competitively priced, so there's no real gain/savings.

Dash harnesses are the most expensive, but are usually the ones that are the most hacked up. You can remove it, lay it on a table, and replace what areas are damaged, then re-wrap. It still won't be as clean as a replacement one, but you will save money.

It's much easier to just pull a dash harness out of the box, and replace the existing one. All the ends/connectors are pretty much a fall-in-place hook up.

.

Hello, I'll be soon starting the dash install of the AAW update kit , on the bench. Just curious what issues you had when installing your AAW kit.

Thanks

[HWYSTR455]

As an alternative to M&H, one source I should have mentioned is Lectric-Limited:

https://www.lectriclimited.com

They are as good if not better than M&H, though I'm not going to argue with anyone about it.

Tips on the AAW classic update kit. Whew.

*Go through the instructions multiple times, before you even attempt to install anything.

*Mark the areas in the instruction that will apply to you install, and beware, it can be confusing.

*Not everything comes with the kit. Save all the clips, etc from the dash, noting where they go. Have extra Packard connectors & terminals on hand.

*Blaze me if you want, but the best way to terminate any ends is with a professional crimper, and quality terminals, using shrink tube on any exposed power runs. No crappy auto parts terminals with those crappy plastic covers on them.

*If you need sources for terminals or tool recommendations, look at some of my other posts.

*Not sure about 67 and before, but 68-up, it's best to remove the dash, with the OE harness attached, and toss it on a bench. Compare the new harness to the OE, take pics and notes.

*If any of the retainers, channels, clips, etc are damaged or missing, many of them are reproduced. Stuff like that not only makes for a clean install, but also makes it last longer and easy to troubleshoot.

*If you run aftermarket gauges, make a sub harness. You can on some models remove the gauge cluster by itself, and it's a lot easier to do if you can just unplug it. Since it's not exposed to weather, using an AMPhenol type plug is acceptable. (You will need an open barrel crimper for those type terminals, but worth having)

*The update kit has an accessory harness for add-ons. If you're not using any of them, I suggest terminating all the extra wires using a AMPhenol connector, so later you can tap into the wires easily (and cleanly).

*You can use OE type harness wrap if you want, and are familiar with using it. Do NOT use electrical tape, or anything with adhesive. Some choose to use loom, which is a good idea, it protects the wire, and split loom allows for troubleshooting and for adding or removing wires. The mesh split loom is my go-to, but you can use whatever you want.

*Take pics along the way. Try to document as best and much as you can for future reference. You will be surprised how useful that can be, even when you think you will never need it.

*If you add circuits, or extend wires, use quality wire (GXL or TXL), no parts store 'primary' wire crap. Try to add the same color wire that you're extending, will prevent confusion when troubleshooting. Can't tell you how many times I've helped folks and every thing is red and black. If you use quality wire, you don't have to use 12ga on everything, 14, 16, and 18 works, depending on the load. Lots of sensors are low amp, and can use 18 or 20ga, same with relay switch circuits.

*If you get tire and/or impatient, stop. Pickup the project when you're in a better frame of mind. When you get tired an impatient, that's when the majority of human error happens.

Calling support at AAW is pretty worthless, once you've paid for it, you're pretty much on your own. It's not too difficult, a lot of point A to point B stuff, don't let it be intimidating. Mark and make notes right on the instruction sheet(s), maybe use sticky notes until you're done, so you don't have a lot of corrections on there.

If found on some of the AAW areas the connectors were cheap. For example, I did the whole car kit, and all the exterior bulb connectors were missing seals or not the type that even accepted seals. Not good. I replaced all of the ones that were unacceptable, and it probably added a hundred bucks or more. When I replaced them, I used new terminals, with seals, and the connectors cost more than the cheap ones.

My floor hi/lo switch was DOA Chinese crap. Come of the specialty connectors, such as the one for the cigar lighter, were not OE type, not insulated, were cheap, but did work. I changed them. Some of the dash light sockets were junk, needed replacing. Some of the instructions were so generic, I just consider them 'wrong'. Definitely check against OE diagrams, and the original harness.

In my case, due to all the modification, add ons, rerouting, etc, I basically paid for the fuse box and a bunch of wire. If you have a lot of mods you want to do, you might consider the basic kit that includes the fuse box and go from there.

In my case, after all was said and done, aside from the floor hi/lo switch, I only had one mistake, and that was I made a section too long, and had to look if under the dash. Everything worked, and considering the effort, that was pretty good results.

My one front speaker in the aftermarket kick panels works intermittently, I think it might be the speaker leads shorting on the body, but that isn't harness related.

I should be able to make this year's Pype/Ames show, if anyone is interested, I will point out the mods, etc.

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[64speed]

Thanks. That's what I figured. This car is rapidly reaching the price of the GDP of Brazil LOL

[Peter Serio]

There are basically 2 major players in the auto reproduction wiring harness biz. American Auto wire and M&H. The both make good products and all of the Pontiac specialty parts places stock from one or the other. AAW is an east coat company and M&H is located on the west coast in case you decide to deal direct.

I bought a complete dash and engine harness for my '63 Lemans from AAW. It was well made and all of the wire colors matched the GM schematic from my shop manual. It is in my car now and I am very happy with it.

In the case of my car they needed a few of the parts (the plug-in ends) from my old harness which I sent them. For your year car I think they can supply you with a brand new ready-made harness; exact to the original so all your switches plug right together.

[Geoff]

I agree with post #2. Mate has just bought a 66 GTO that the PO owner had bought a AAW complete wiring harness for....... & attempted to rewire. Many wire colours are different from original & the instructions leave much to be desired....

[HWYSTR455]

My memory isn't as good as it used to be, so I am documenting my install. Not a small effort, and not really that much fun either!

To further complicate matters, I'm also doing EFI, and am customizing that harness as well. Uhg.

The crimpers alone can add a considerable expense. I also have a large assortment of connectors (weatherpack, metripack 150, 280, Deutsch, etc), seals, pins, retainers, you name it. It all adds up, but in the end, it will look and function great. Any leftovers can be used on other projects too.

I went through trying to find just fuse boxes, wanted ATO fuse box, but the manufacturers only sell in quantity, and none of the harness manufacturers will sell just the box. Capitalist pigs. If I would have been able to do that, I would have made one from scratch.

Good wire isn't cheap either, and it's best to use the appropriate wire for appropriate jobs. For the most part, TXL is what should be used. As an example, 16ga is about $3 per foot, depending on quantity.

When you look at it that way, the $600 or so for a dash harness isn't such a bad deal, and really, one can wonder how they do it that cheap.

.

[Lemans64]

If your not real good with electrical stuff I would stick to M&H or something similar. It's plug and play, no guessing as to where or why. It may be a little more expensive than the build your own generic harness but it will install in way less time and there won't be test fits while laying inside down under the dash, nor will you have to tape the harness, then take apart and retape, LOL.

[JLMounce]

I have M&H stuff in my car. I discussed with them at length the same thing, going with either modified stock harnesses or going customed harness. In the end, it was just better to buy the reproduction harnesses. The only thing I have that needs any type of customization is the FiTech and that's easily handled through the stock replacement harnesses.

So while the expense is there, it's definitely your best bet.

[64speed]

Thanks guys. I called M&H and told them what I was doing and what I wanted to accomplish and everything all in ride and everything is around 1200 so basically I'm paying another 500 bucks to avoid a major headache. I can live with that.

[64speed]

I bought the M&H harnesses and they look pretty straight forward so I am glad I did. I have one question though. I did not want to hack up or splice a new harness so I bought the harness that had been modified for HEI and internal regulated alternator. For the fuel injection accessories I bought a painless wiring 7 circuit add on box that adds 3 keyed and 4 always hot junctions. I plan to run the HEI wire to it to power the keyed circuits and connect the hot circuits straight to the battery. Does that sound like the right way to do it?

[HWYSTR455]

Originally Posted by 64speed

I bought the M&H harnesses and they look pretty straight forward so I am glad I did. I have one question though. I did not want to hack up or splice a new harness so I bought the harness that had been modified for HEI and internal regulated alternator. For the fuel injection accessories I bought a painless wiring 7 circuit add on box that adds 3 keyed and 4 always hot junctions. I plan to run the HEI wire to it to power the keyed circuits and connect the hot circuits straight to the battery. Does that sound like the right way to do it?

Actually, you would want to connect the power feed for the add on to the common post on the starter, or move the starter relay function (or common post) to an external ford sol as done in the hot start fix. If you put the battery in between the power source (ALT) and the load, the load will pull from the batt first. If that makes sense.

Most EFI companies state that the ECU MUST be plugged directly to the battery, which always puzzled the heck out of me, but I guess they are taking into account all factory wiring scenarios. Sometimes that will be one of the first things they ask when you call support, so however you want to handle that is up to you. I just suck it up and run it right to the batt, but I'm on the wall this time around when I finish my current wiring project.

I strongly suggest running deep cycle batteries when adding 'loads' to your factory electrical system. I generically use/recommend the Optima Yellow tops, which are only about $50 or so more than a good lead/acid battery.

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[HWYSTR455]

I too have heard spotty reviews from M&H lately, though I personally have always had good luck with them. I do recall once when I asked about upgrades, the pre-sales person got impatient with me and short.

I'm doing an AAW classic upgrade harness for my current project. It's similar to the Painless type harnesses/kits, and all I can say it is far from painless. If I were to do it again, I would only order the dash harness, use OE for the remaining, and modify them. Main reason I went with an aftermarket harness is for the ATO fuse box, an item you can't buy only one of, the manufacturer requires a minimum purchase for like 100 or more.

I should do a separate thread on that to give others insight, from my experience using the AAW harness. It would save a lot of people from some of the hurdles and pitfalls I experienced.

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[64speed]

Anyone?

[gassman_67]

I have all M&H harnesses, I got them to fabricate the engine harness with a HEI setup. I'm going to install Holley Sniper EFI, Holley dual sync and a MSD 6AL digital. The holley kit comes pre wired for a fuel pump (with relay) I will also use the 2 electric fan outputs, I just plan on wiring the 2 ground trigger relays close to the fans/battery. No additional fuse box needed.

[Tempest]

I purchased the entire wiring system for my 64 Lemans from M&H and am very disappointed. The plug at the firewall for both the engine wiring harness and the headlight wiring harness would not plug together. the terminals were so cheap that they started breaking. The dash harness was about 5 inches too short to hook up to the ribbon harness easily, and the "customer service" was awful.

The entire system is what I would expect from a 'Made in China' product.

M&H was sure eager to promise me the world to secure the order, but after that, it was, and still is, a nightmare.


I don't know where to tell you to go to get a quality wiring harness, , but I would seriously consider an alternative to M&H.

Good Luck

[lugnutx2]

I used Lectric Limited harnesses on my corvette, looked factory and fit well.

[64speed]

The M&H harnesses look exactly like the harnesses I took out other than one being clean and one being dirty and all jacked up and spliced. I always thought M&H were THE authority on factory wiring harnesses. I guess I’ll find out in about a year when I’m ready to start putting some power to some things.

[dlloyd]

Originally Posted by 64speed

The M&H harnesses look exactly like the harnesses I took out other than one being clean and one being dirty and all jacked up and spliced. I always thought M&H were THE authority on factory wiring harnesses. I guess I’ll find out in about a year when I’m ready to start putting some power to some things.

64speed, have you powered up your M&H harness? I have been talking with M&H about a complete wiring harness for my 65 GTO. I am waiting for the quote from M&H. Just curious how your turned out.