Hello,

I, like many here, am suffering from a wiring harness that is so crispy that the connectors are falling off. My plan is to order new ones from Ray @ Malloy Mazda, but I wanted a rough estimate from those who've replaced them all before.

How many harnesses are under the hood and roughly how much would it cost to replace all of them?

Thank you for the help.

 

there's several.

Battery/Starter Harness
Coil Harness
Engine Harness
Front Harness

The one that most people replace is the engine harness. It'll be around 800-900. If you're gonna replace the engine harness, I think you'd probably want to go ahead and get a new coil harness, too. That's kinda up to your needs though.

If you get into purchasing a Front Harness, then even with Ray's generous discount I hope you bring some lube.

 

Thank you for the response, how much does the coil harness run?

What does the front harness entail?

 

No clue on the coil harness. I wanna say 80ish? I think it's a bit steep for what you get; however, others feel otherwise. That's fine b/c it really doesn't matter. When they're brittle and broken, there's not a lot of options.

Check out this link. It'll answer ALL of your harness questions.

https://www.rx7club.com/showthread.p...hlight=harness

 

You might need to take out your dash in order to take it out because the wiring harness goes from the passenger side under the dash, through the fenders, through the front support, through the driver side fender, to under the driver side dash.


In order to get a brand new harness it might be around 4-5k

I think it's like 1.4k - 2k for a brand new front harness, then like 900 for the engine harness, and then the others.

 

I don't know about the cost, but unless you got lucky, pulling the dash is the easiest way to get the front harness out.

What kind of problems are you having? Hell, why not try rewiring and fixing what can be fixed? A little bit more info please.

 

Dear god, i hope I never have to pull the front harness then.

 

Ah, it ain't that big a deal. Just time consuming.

 

FYI the battery/starter harness is about 485ish from ray when i got mine it was pretty crispy and hacked so it wnt good matched with the new engine harness

one of the best things i spent money on for this car and should be on the top of everyones short list if its an older harness. both of them engine and batt/start

z

 

From the sounds of it I'll be doing just that, the engine harness and battery starter harness. The coil harness I'm unsure of, but if it's cheap I might just do that anyways and leave the front harness.

I'm in the same situation as proz07, my wires are extremely brittle and hacked. Regarding the hack job, it really makes me wonder what in the world people are thinking. Sounds like this is over a grand in wires!

Would OEM be cheaper than a custom harness? Or would the mazda connectors be a problem should I go custom?

 

I don't know what a cost of a custom harness would be. You'd definitely have to reuse some of your connectors.

A few folks have tried to source all the connectors with similar hopes. To my knowledge none of them have been able to complete this task. Some of the connectors were supposedly on "back order" until a large quantity order was placed.

There was a posting I saw a while ago about an LA shop that specialized in wiring harnesses. I forget their names. . . . .

 

BAM:

http://www.apexspeedtech.com/services.html

 

There is one harness that lays across the engine block and is exposed to the highest temperatures. That's the "emissions" wiring harness that most people end up replacing.

The other harnesses are usually in better shape.

 

That main front harness is $2,000+ at Ray's discounted rate.

Jack

 

Instead of replacing the harnesses with stock, I was thinking about upgrading to an aftermarket standalone ECU harness with sensors.

My questions:

• Which standalone ECU unit would be the best in using its own wiring harness and sensors?
• Widely supported by tuners?
• Has a variety of control elements?

 

The most common tuner ECU for the FD, is the Apexi PFC. With a datalogit, it can adjust any variable that you'd need. Unfortunately it uses the Stock harness.

Haltech might be an option but you'll want to call around and speak with ROTARY tuners before you make a final decision. Neptune Speed is a good place to start. They're out of Huntington Beach, CA and have a reputation for having a kick-*** rotary tuner in house.

I wouldn't toss the PFC option out the window until you figure out how much of a PITA it'll be to have a different ECU. PFC is the standard ECU atm and most rotary tuners will be most familiar with it.

 

I haven't caught any of the threads coming up on RX7club, but I've answered a few of these questions over on v8rx7forum.

I do custom harnesses/wiring/electronics, similar to what Apex Speed does (although they certainly are more prestigious with IRL/Champ Car wins under their belt)... my products are found in a couple Formula D and Redline Time Attack cars competing this year (Conrad Grunewald's Hankook Camaro and Matt Powers' Need For Speed S14) and countless Pro-Am level cars, privateer/weekend racers, etc.

Unless a large portion of your connectors are physically broken (meaning intermittent contact, not just a chipped tab/etc) and/or a bunch of cracked insulation with exposed wire, there is now way I would pay thousands upon thousands for a new harness, just to be OEM and run into the same problems as before.

My customers pay for my products because they want to either clean up the engine bay, or completely relocate the engine bay crap (read: fusebox, relays, etc) for a tucked look. If you have a connector that looks old/brittle or maybe has broken, find another connector!

This isn't a Ferrari or a pristine 50yr old collector car ~ I don't see the value in spending thousands to maintain the OEM configuration with new parts. If a connector is in a hot spot, relocat it with sleeved wire that can take the heat, or shield it. If you have cracked insulation and exposed wire leading to a connector, depin it, replace the wire (which is probably corroded, so take an extra inch or so off with the exposed section), sleeve it, and repin the connector.

If you're going to spend thousands on a front engine compartment harness, first realize that the very best outcome is that you'll be right back to where you started, and the same money can be spent with a company like mine to actually improve the design by simplifying and/or relocating the components and fabricating a new harness with much higher grade materials.


To put my money where my mouth is, I'm in the process of making one of my Mil-spec chassis harnesses for my FD (in addition to a Mil-spec harness for my LSx) and will document the trouble spots and try to recommend common-sense fixes as I disassemble my OEM chassis harness to give the community more options when it comes to repair (rather than buying new OEM or paying for Mil-spec harness work).

 

That sounds great, what are your rates?

From my situation, the connectors are just as bad as the wires themselves. I have some loose wires that have been hacked and I don't know where they go. Other plastic connectors have fallen apart and am now using crimped sheathed connector ends. As unfortunate as it may sound, I may need to start from ground zero on some of the harnesses, like the engine harness, in order to take advantage of services such as those you're offering.

My hopes would be to replace my Power FC with an ECU unit that utilizes its own harness to help with the wiring problem. On Grimple1's note, I think I may contact local rx7 tuner shops to hear their opinions on the matter. Afterall, it would be sad to alleviate the wiring problem only to be left without a local tuner for the ECU. If anyone has gone through this process, please chime in. I would like to hear your input.

 

If you want me to shoot me a PM with specifics, I'd be happy to discuss rates. I'm not yet a site sponsor, so I don't want to go advertising or starting any "group sales" threads.

In my experience, if you have connectors that are missing/failed, the easiest thing to do is find another vehicle (most likely doesn't have to be a FD) and snip the connector off with a few inches of wire. This isn't the most elegant solution, but for older vehicles where factory connectors are not available, this is certainly the most efficient method.

As popular as the Power FC is, there are certainly more powerful ECUs with much more intuitive/widely available software. The Haltech Platinum series is where you'll see the most bang for your buck, in my opinion, and we can put you together a harness for it (or any other standalone) if you'd like.

In southern California there are quite a few well-known tuners out there, but I have a colleague named Steve Shadows that does phenomenal tunes with his Eddy current Dyno Dynamics dyno. I'm sure it's been covered in dyno threads here as it has on every other performance car board, but if you drive a car here on Earth within the laws of physics, you're going to get a better tune on a load-applying Eddy-current dyno rather than an inertial dyno. I know JRX Rotary has been historically popular here, and Juni is actually right up the street from me in Irwindale ~ he'd be a great resource to talk to as well.

 

Look up some threads by HWND, you will enjoy.

 

Can you link me? I can't seem to find anything relevant to this discussion.

 

I also looked through all his threads and the only one that I can think of that's relevant is his Efini ABS swap which turned out to be kind of a bust after they realized it's still a 3-channel setup. I'm not trying to be a dick, just curious what I missed.

 

I'm sure you've both read it.. but this is a good one. And has some information about connectors and such.

https://www.rx7club.com/showthread.p...harness&page=2

 

Great thread, I actually hadn't seen it. I feel the same way as HWND, obviously, that paying out the *** for an OEM harness, then having it stripped of a few wires and loomed with cheap plastic corrugated split-loom is ridiculous.

I also agree that using new wires/pins in used OEM connector bodies is the most realistic option for making a new harness, if you can find all the different pins.

 

I think an aftermarket harness solution would be a good money maker for someone. It's certainly been a good revenue generator for Mazda.

I suppose the best way to go about getting the parts is to just start purchasing up "crispy" harnesses around. I'm sure you could get mangled ones for a fair price and then pick through the good and the bad.