banzaitoyota
banzaitoyota None
5/11/11 7:55 p.m.

Has anyone done an ISIS multiplex Wiring harness yet?

tuna55
tuna55 SuperDork
5/11/11 9:00 p.m.

Nope. Sorta wanted to after the hotrod article, but I don't see enough good for someone who isn't building a hugely complicated 100k build.

novaderrik
novaderrik HalfDork
5/13/11 9:02 p.m.

i can't stand the modules in every car built since the mid 90's.. why would i add that kind of unnecessary expense and complexity to my 20+ year old junk?

Ranger50
Ranger50 HalfDork
5/14/11 7:26 a.m.
novaderrik wrote: i can't stand the modules in every car built since the mid 90's.. why would i add that kind of unnecessary expense and complexity to my 20+ year old junk?

It is wiring simplicity at it's finest, not additional complexity. Instead of running multiple wires for a similar circuit fore and aft, you run ONE data cable, power, ground, and a series of shorter wires to your desired components. The modules weigh less then the combination of wires you would need, plus they can tell you what is electrically broke without having to chase the problem down. Take this as an example, turn signals. You are going to need at least wiring for 2-4 bulbs per side of the circuit, plus the additional circuit to power them up, low side, when the lights are on. How much wire are you running to make this all work? If you use the module system, you just provide an input and output(s) to the module and it does the rest.

Yes, electrical works sucks, but it really is simply easy.

carguy123
carguy123 SuperDork
5/14/11 8:32 a.m.

The simplicity of the system is what looks good to me, BUT how do you retrofit it to an older engine ecu, etc?

mad_machine
mad_machine SuperDork
5/14/11 8:50 a.m.

I work with similar systems in theatre. It is SO nice to run power to an light and then just a smaller data line to it's onboard processor.

Unfortunately, that idea does not work with pars and lekos..

tuna55
tuna55 SuperDork
5/14/11 9:37 p.m.
Ranger50 wrote:
novaderrik wrote: i can't stand the modules in every car built since the mid 90's.. why would i add that kind of unnecessary expense and complexity to my 20+ year old junk?

It is wiring simplicity at it's finest, not additional complexity. Instead of running multiple wires for a similar circuit fore and aft, you run ONE data cable, power, ground, and a series of shorter wires to your desired components. The modules weigh less then the combination of wires you would need, plus they can tell you what is electrically broke without having to chase the problem down. Take this as an example, turn signals. You are going to need at least wiring for 2-4 bulbs per side of the circuit, plus the additional circuit to power them up, low side, when the lights are on. How much wire are you running to make this all work? If you use the module system, you just provide an input and output(s) to the module and it does the rest.

Yes, electrical works sucks, but it really is simply easy.

If it's a racer car with brake lights, head lights, ignition and maybe a fuel pump, the setup is WAY more complicated than the normal wiring. If it has two audio things, power windows, power locks, power antennae, fuel injection stuff, nitrous, power sunroof and remotely operated ashtrays, sure, this system is easier.

Teh E36 M3
Teh E36 M3 HalfDork
5/14/11 10:42 p.m.

I think it's a great idea, just not for $900 for the three module kit.

peter
peter Reader
5/14/11 11:46 p.m.

Are there any open-source versions of this? Something like the MegaSquirt, but for chassis wiring? It seems like a great idea, but for the limited number of outputs that something like the new Factory Five creation would need, it's mega-overkill.

novaderrik
novaderrik HalfDork
5/15/11 12:29 a.m.
Ranger50 wrote:
novaderrik wrote: i can't stand the modules in every car built since the mid 90's.. why would i add that kind of unnecessary expense and complexity to my 20+ year old junk?

It is wiring simplicity at it's finest, not additional complexity. Instead of running multiple wires for a similar circuit fore and aft, you run ONE data cable, power, ground, and a series of shorter wires to your desired components. The modules weigh less then the combination of wires you would need, plus they can tell you what is electrically broke without having to chase the problem down. Take this as an example, turn signals. You are going to need at least wiring for 2-4 bulbs per side of the circuit, plus the additional circuit to power them up, low side, when the lights are on. How much wire are you running to make this all work? If you use the module system, you just provide an input and output(s) to the module and it does the rest.

Yes, electrical works sucks, but it really is simply easy.

and what happens 5, 10, or 20 years down the line when a module goes all wonky and the company that made it is out of business?

i can't see how it's any more simple than a regular harness- there are maybe 5 or 6 wires running to the back of the average car lumped in a harness that's usually less than 1/2" in diameter and weighs maybe 10 pounds total. the front light harness is about the same.

but i guess if you like the idea of a radio that stays on for a while after the key is shut off or a dome light that stays on for a while after the door closes, then fades off slowly- neither are things that i personally like- then this kind of thing might be worth the expense.

banzaitoyota
banzaitoyota New Reader
5/17/11 7:07 p.m.

I hear your comments/concerns. My RX2 wiring harness is toast(literally) it randomly short and has caught fire.
OPTIONS
1.Continue to repair as needed, creating a wiring nightmare! 2.Disassemble and refurbish (Number Five is Alive!)
3. Ron Francis/American Auto wire universal replacement harness
PRO's
1. Can continue to use car as is
2. Maintains original appearance and function 3. 2/3 the cost of ISIS

CONS 1. Hacked harnesses suxors 2. Brittle connectors, maintaing a markrked up copy of diagram, unneeded crap in harness (Been there Done that) 3. Based on GM ford Components

With the ISIS I can use the original switches and maintain the dash in a stock appearance. I can program the fuel pumps and electric fans for various functions not available with "conventional" harnesses

Rob_Mopar
Rob_Mopar Dork
5/17/11 7:52 p.m.

I've been pondering this for our Barracuda convertible project. Not much of the original harness is still intact, and what is, is pretty brittle. Full reproduction stock harness would cost at least as much as the ISIS setup.

Having worked in IT for too many years I do have the concern that if there is a failure in a module several years from now, the module will be obsolete and so will repairing it. But then again, it might not be hard to re-retrofit a contemporary module system at that time.

I've been leaning toward a Painless harness, but there are several other projects ahead of that one right now so it isn't an issue.

I'd love to hear from people who have ISIS in their car, and from the people who installed/set it up.

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