For those of you running only an ecu and autometer guages that's electrical, besides fuel pump and fan, what harness do you use? And i still want to keep my alternator. I have a shell with NOTHING in it, wondering what i should use for a harness.


EDIT: So i decided to work with what i have. So what i have is basicly ecu pigtail harnesses and a chopped up obd1 engine harness, that i can combine together as a 1 peice harness. I think i have it down but have a few questions.
1. What's the difference between logic ground and power ground?
2. How will i go about running the alternator wiring?
3. Do the power wires on the engine harness need to go to a relay or can i go from the battery to a switch then to ecu?
4. Will the fan and fuel pumps need relays?
5. If i need relays, where would be the cheapest place to get them? are all relays the same?


Modified by UNKNOWN_MEMBER at 2:59 AM 9/28/2008

 

It would be helpful to tell us alittle more, like what chassis, engine and obd the computer is. There are a few options out there for a race only car.

You could get a used harness from a salvage yard, or someone on here, and just use the plugs you need. this is of course the cheapest and easiest way to go.

You could build your own harness from start to finish, which will take some skill. Doing it this way allows you to save some weight, and its easier to work with. This is probably by far the most time consuming, but not the most expensive way to do it.

The last option is to have someone build you a harness. I'm not sure if Locash still makes them, but they use to sell a race harness set up. Also you can check with Rywire, T1 Development, and Chasebays. I think any of those guys could also build you a complete engine harness.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by UNKNOWN_MEMBER &raquo;</TD></TR><TR><TD CLASS="quote">For those of you running only an ecu and autometer guages that's electrical, besides fuel pump and fan, what harness do you use? And i still want to keep my alternator. I have a shell with NOTHING in it, wondering what i should use for a harness.</TD></TR></TABLE>

I call it the 5 and fire..

Get yourself a obd2B engine harness off a 2000 civic SI. This harness plugs Directly into the ecu.. There is not in-car harness. Harness to ecu.


Also get a OBD2b to OBD1 conversion harness..

Now you have a B motor that will run in any chassic

The 5 wire you have wire are..

Fuel pump
Ignition
Starter
ECU
Fan.

I have done this to a couple cars.. Its clean. Simple. And up to date.

 

chassis is EG. motor is b-series vtec. running obd1 ecu hondata. <TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by havok hybrid &raquo;</TD></TR><TR><TD CLASS="quote">

I call it the 5 and fire..

Get yourself a obd2B engine harness off a 2000 civic SI. This harness plugs Directly into the ecu.. There is not in-car harness. Harness to ecu.


Also get a OBD2b to OBD1 conversion harness..

Now you have a B motor that will run in any chassic

The 5 wire you have wire are..

Fuel pump
Ignition
Starter
ECU
Fan.

I have done this to a couple cars.. Its clean. Simple. And up to date. </TD></TR></TABLE> so how will i connect the rpm and water temp guages? Also i wanted to run the fuel pump, fan and starter with 3 different switches, how would i wire that and am i going to have to run relays?

 

Starter you want on a momentary button.

For the others you will want relays or switches that can handle the load. Typically a relay is better so you dont have to worry about it.

In a race car application, the relay you choose may matter too. In some really fast cars, they have to much vibration and need different kinds. Such as the shop I work for...they are running in the low to mid 6's in the 1/4 with a alky/blower setup.

I did my own harness and didnt find it that difficult, but I am also an electrician.

As far as gauges...you just need signal, power, and ground for each.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by UNKNOWN_MEMBER &raquo;</TD></TR><TR><TD CLASS="quote">chassis is EG. motor is b-series vtec. running obd1 ecu hondata. so how will i connect the rpm and water temp guages? Also i wanted to run the fuel pump, fan and starter with 3 different switches, how would i wire that and am i going to have to run relays?</TD></TR></TABLE>

You run switches to the 5 wires I pointed out.

each switch will do somethin.

I run a 5 panel switch with a button.

Starter..
swtich to ecu.. = powers the harness
switch to fuel pump = fuel
switch to fan = cooling

ETC...

You will connect the temp and rpm to the ecu output wires that output that signal.

Search for [google]obd2b pinouts[/google] if you want to wire it to the obd2 side.. OR search obd1 and Tee into your jump harness.

 

THere are plenty of ways of doing a harness its just how picky you want to be.

were building a SFWD based 93 hatch and we took out the whole electrical and replaced with with a painless race car harness that still uses lights and stock switches!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HondatagirlPea &raquo;</TD></TR><TR><TD CLASS="quote">THere are plenty of ways of doing a harness its just how picky you want to be.

were building a SFWD based 93 hatch and we took out the whole electrical and replaced with with a painless race car harness that still uses lights and stock switches!</TD></TR></TABLE> that doesnt help lol. can you be a little more detailed like who built the harness, what harness did you use for base, etc..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by UNKNOWN_MEMBER &raquo;</TD></TR><TR><TD CLASS="quote"> that doesnt help lol. can you be a little more detailed like who built the harness, what harness did you use for base, etc..</TD></TR></TABLE>

It said in my post Painless

i got the race car harness 50002

Their harness has everything from fan to fuel pump, fuel level and going to all the gauges. Comes intact with fuse box turn signal relays and flashers

 

ooohhh i thought you were refering it to being painless. my bad

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HondatagirlPea &raquo;</TD></TR><TR><TD CLASS="quote">

It said in my post Painless

i got the race car harness 50002

Their harness has everything from fan to fuel pump, fuel level and going to all the gauges. Comes intact with fuse box turn signal relays and flashers</TD></TR></TABLE>

Painless is a great harness for non EFI car. I beleive that the OP is looking for a engine harness . Only a couple companys makes them for honda's and at the price they are.. you are way better off doing a obd2b to 1 setup as BASE then rewire it from there.

to painless products though.

 

is there an advantage to not using the 96 - 98 harness which has all 3 plugs? just wondering cause im going to wire up our crx this way!

 

also i updated my post. i want to wire up my own harness from scratch, but have a few questions, check them out...

 

Its better to have relays on the fan and fuel pump. for larger fuel pumps a relay is needed.

Most of the relays are the same, but there is a 4 pole and 5 pole relays. I normally just use 4 pole relays. Better relays have a connector on them and not just setup up to use with crimp connectors.

Is the car for drag racing? is the battery located in the stock location?

This may have a effect on how you wire the alternator wire for a kill switch.

 

yes car is for drag racing. and no the battery is relocate in front of the passenger wheel

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by A train &raquo;</TD></TR><TR><TD CLASS="quote">is there an advantage to not using the 96 - 98 harness which has all 3 plugs? just wondering cause im going to wire up our crx this way!</TD></TR></TABLE>
I dont know if its different. Does 96-98 harness plug directly to the ecu. If so . Then it should would the same.

The use of relays to all switch items minus the ecu is needed. Make sure to run fuses somewhere.

I will have pix as soon. My car is not around at the moment.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by UNKNOWN_MEMBER &raquo;</TD></TR><TR><TD CLASS="quote">For those of you running only an ecu and autometer guages that's electrical, besides fuel pump and fan, what harness do you use? And i still want to keep my alternator. I have a shell with NOTHING in it, wondering what i should use for a harness.


EDIT: So i decided to work with what i have. So what i have is basicly ecu pigtail harnesses and a chopped up obd1 engine harness, that i can combine together as a 1 peice harness. I think i have it down but have a few questions.
1. What's the difference between logic ground and power ground?
2. How will i go about running the alternator wiring?
3. Do the power wires on the engine harness need to go to a relay or can i go from the battery to a switch then to ecu?
4. Will the fan and fuel pumps need relays?
5. If i need relays, where would be the cheapest place to get them? are all relays the same?


Modified by UNKNOWN_MEMBER at 2:59 AM 9/28/2008</TD></TR></TABLE>

1. What's the difference between logic ground and power ground?

IDK Just ground them both.. to the same place

2. How will i go about running the alternator wiring?

You only need 1 one the wires from the alternator. (look at obd1 pinout) AND
The Big WHITE wire on the top .. thats bolted on . .That goes back to the POSTIVE side of the battery.. It also need to be fused..

3. Do the power wires on the engine harness need to go to a relay or can i go from the battery to a switch then to ecu?

No You do not need a relay.. you need a FUSE .

4. Will the fan and fuel pumps need relays?

YES they need relays. The are simple to wire up . (switch on = relay on)

5. If i need relays, where would be the cheapest place to get them? are all relays the same?

Local parts store. 12v relays 4 post.

 

I'm looking at the obd1 pinouts right now. on the A connector there's an alternator control. and on the D connector there's a alternator FR charge signal. There's 4 wires on the plug, they're labeled "C", "FR", " IG", and "L" on my electrical book. C and FR goes to ecu, then pin 10 on connector D goes to ELD. IG goes to a junction connector and L goes to underdash fuse/relay box

 

I beleive you only need to run the alternator FR charge signal to the ecu... and the big wire on the top to the battery..

That is how they do it with true stand alone .

See what you can dig up on the net.

 

my alt did not work without hooking it up to the fuse box

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LA_HONDAS &raquo;</TD></TR><TR><TD CLASS="quote">my alt did not work without hooking it up to the fuse box</TD></TR></TABLE>

you expected it to work lilke that?

The only bad thing about doing harnesses like this is if you mess up goodluck finding the problem.

Take your time and just double check everything before you do it!

 

no i did not

the only wire thats not hooked up is for the batt... light


btw i was talking about the blk/yel wire

 

im in the same boat made my own harness for headlight to tail light. made my own cluster out of autometer gauges. now im getting ready to start on my engine harness.
What do i do for ELD since i do not have a factory fuse box? what wires will i need coming off the alternator. i know top post goes to the battery. but not sure about the 4 wires on the connector.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RedneckRicer &raquo;</TD></TR><TR><TD CLASS="quote">im in the same boat made my own harness for headlight to tail light. made my own cluster out of autometer gauges. now im getting ready to start on my engine harness.
What do i do for ELD since i do not have a factory fuse box? what wires will i need coming off the alternator. i know top post goes to the battery. but not sure about the 4 wires on the connector.</TD></TR></TABLE>

I'm looking at the obd1 pinouts right now. on the A connector there's an alternator control. and on the D connector there's a alternator FR charge signal. There's 4 wires on the plug, they're labeled "C", "FR", " IG", and "L" on my electrical book. C and FR goes to ecu, then pin 10 on connector D goes to ELD. IG goes to a junction connector and L goes to underdash fuse/relay box

Anyone else have anything to add???

 

for the electrical gurus