Early model harness wiring chart

[lifeiskaos]

Also i just noticed you have at 18>7...it should be 18>18

craig im about 80% sure i wired pin 18 to pin 18... maybe double check? im pretty sure the single wire on the back of the cluster that everyone talks about is the one i pointed out last time i was at your house.

[Kerrath]

Getting speed signal from cluster makes sense, but which one is it? Is it the single wire that goes into the green (I assume speedo) plug?

Also, what's the 3rd wire on the C104 for? The black on the chassis side should be tach, and there's a green and white/yellow one. I think the green is fuel consumption and don't know what the last is.

[kronus]

^^ are you both at cal poly Pomona?

You're like 15 minutes from me and Farbin if so. Let me know if you need a hand doing stuff between any Thursdays and Saturdays...

[Kerrath]

Mitchell's at cal poly, I'm going to Citrus, but the car's in Duarte. Kinda a bitch. I'd appreciate any help you can give though.

[kronus]

Well, I'm not familiar with 24v swaps, but generally handy at electrical stuff. Farbin is also eventually doing an early model 24v swap. (he's got the early square connector, so it should be simple)

I'll take a peek at the ETMs when I have some time (or procrastinating on college shit) and get familiar with it. Seriously, let me know if you need a hand.

[lifeiskaos]

thanks dude! yeah those etm's are useful sometimes but they're often a pain in the ass and dont give the information we're looking for.

maybe you can pm me your phone number and i'll call you sometime?

[mongule]

Getting speed signal from cluster makes sense, but which one is it? Is it the single wire that goes into the green (I assume speedo) plug?

Also, what's the 3rd wire on the C104 for? The black on the chassis side should be tach, and there's a green and white/yellow one. I think the green is fuel consumption and don't know what the last is.

Yep In the back of the cluster where there is a a wire ( actually two if you have cruise control) going into the green plug. Thats for the speed reference.

In the C104, fuel consumtion is yellow/white. The green, I'm not sure what its for but in all the early model wiring diagrams I saw no one used it, So I didnt and everythign works fine.

[lifeiskaos]

Yep In the back of the cluster where there is a a wire ( actually two if you have cruise control) going into the green plug. Thats for the speed reference.

In the C104, fuel consumtion is yellow/white. The green, I'm not sure what its for but in all the early model wiring diagrams I saw no one used it, So I didnt and everythign works fine.

lol well i guess we need to unsolder the green wire... i dont understand why nobody who has swapped an m50 into an early model hasnt documented their wiring. if they did, it certainly aint easy to find

[Kerrath]

lol well i guess we need to unsolder the green wire... i dont understand why nobody who has swapped an m50 into an early model hasnt documented their wiring. if they did, it certainly aint easy to find

No we don't. The black wire on the chassis side is the green wire on the engine side. Soldered pin 20 to green wire which plugs to black wire which is tach. NO MORE UNSOLDERING. >:[

[mongule]

Well on my swap swap black chassis side went to black engine side and on all the other swaps I've seen it was liek that.

I might not be understanding what your saying though

But if your sending black ( from the C104) to pin 20 then that seems right.

[Kerrath]

Yeah. On the body side I have black green white/yellow. I was at the jy and snipped the connectors from another early model. Chassis side = black green white/yelow, but the engine side was green brown and something else. Pin::Pin is not hard. At least I know I got the wire right Lol.

While I have my adapter unwrapped I'll update my wiring chart with what is ACTUALLY wired.

[mongule]

Ah ok makes sense then.

[Kerrath]

Kind of out of date to respond but I finally got the other side of the C104 and wired it up. Also got a plug to go tot he back of the cluster to attach to pin 14 of E34 harness. Fired it up and the tach worked. Revved it past 5k rpm to BDC. Won't display any higher than that of course, but its revlimit was there, not cutting out at like 5200.

So in short, both wiring to C104 and adding a second connector to the speedo plug to pin 14 worked. Just the coolant wiring left to do.

I believe it's the one pin I've gotta use.
I'm curious, how does a 1pin sensor work?

[mongule]

the sensor itself is the ground.

[lifeiskaos]

how does it vary it's signal? on a two wire sensor, i understand that it is like an adjustable resistor, and the gauge reads how much voltage is returned, but as far as i know it cant only do that with one wire?

like, the oil pressure switch for example, makes sense to be a single wire ground switch essentially, because all it has to do is turn on a light, but the coolant temp has to control a gauge...

i dont get it either