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Complete engine wiring harness

Old 11-25-2012, 07:06 PM
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Complete engine wiring harness

I was told by a shop that I have a short somewhere in my wiring harness and to track down the problem could possibly cost thousands to fix. I don't want to tackle that mess of wires by myself and rather than fix one short I'm inclined to buy a complete wiring harness and just have it all fixed in one swoop. I have a 3.1L TPI V6 firebird, could you guys tell me where I might find a complete harness so I can fix this?
Old 11-25-2012, 08:42 PM
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Re: Complete engine wiring harness

I'm wondering the same thing. Bet you could find a v6 harness in a scrap yard. I've gotta find one for my 350. That's gonna be harder
Old 11-25-2012, 08:52 PM
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Re: Complete engine wiring harness

Have you looked at a painless wiring system? The make complete wire systems and sections, depending on what you feel needs to be replaced
Old 11-25-2012, 09:18 PM
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Re: Complete engine wiring harness

fervernt, if I have to go the junkyard route I'll look for some 350s and see if I can find anything for you. I know of a place called paradise alley that has a lot of rare firebird and camaro stuff. i'm sorry you're having the same problem.

iosigma, could you give me a little more info about painless wiring? all i was really told by this shop was that somewhere in the engine wiring harness was a short and it was causing my idle to surge erratically. i'm sure there are several different harnesses for these cars but i can't say i've seen anything specifically for the engine alone. at this point i'll take any help i can get.
Old 11-25-2012, 09:40 PM
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Re: Complete engine wiring harness

Well..is the engine throwing any codes? And I may be off base, but on my 305 it has an HEI distributor system. There's a module that controls this spark, may control your idle as well..maybe it's adjusting the timing to much? I know my car idles up till the o2 sensor and cats heat up and then settles in about 650 rpm. There's a number of things that could cause an erratic idle. Never heard of a short in the wiring system causing it. I did have a delco battery that had a broken plate inside of it...at rest (car in park) the battery would charge fine, show good voltage..as soon as I started driving, the plate would shift and (dead short) the battery and even kill the engine and start right back up at high way speed. Took about two weeks to figure out what was wrong.
Old 11-25-2012, 09:41 PM
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Re: Complete engine wiring harness

And to answer your question. I would just google painless wiring. And go to their website. If that ends up being the issue. Bad ground on the back of the block may cause this as well.
Old 11-26-2012, 11:05 AM
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Re: Complete engine wiring harness

I have a harness around here from a 91 camaro V6. I assume they are the same and was taken form a running car
Old 11-26-2012, 12:28 PM
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Re: Complete engine wiring harness

Before you do anything to your harness, post questions about your specific problems and any info that the shop gave you about what sensor(s) are involved. I'm suspicious of what you were told. Be sure to post any error "codes" from the computer. Let's be sure it isn't something allot simpler to fix before swapping the harness. Any used harness you find is likely to have it's own problems to deal with.

If they think there is a short, then they should know which wire (or at least which circuit) has the problem and what sensor or control is being affected by it. Then it shouldn't be that difficult to bypass the harness on that circuit and see if the problem is solved.
Old 11-26-2012, 09:29 PM
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Re: Complete engine wiring harness

iosigma, i checked my codes a couple of months ago and it kept showing a code 13 (bad o2 sensor). Usually in warmer weather (especially when it has sat for awhile without being driven) i've seen it idle as high as 2,500 rpm and after awhile it seems to pan out as it's being driven. When I put the car into gear it seems to drop the idle some. On a few occasions when the car wasn't being given gas the idle would bottom out and the car die but it would always start back up. What does this sound like to you cause I'm stumped? The shop told me that it was likely a short in the wiring harness and that it could be a couple hundred to fix or several thousand, truthfully I think they just wanted me out of their hair.

6six6, is it from a 3.1L v6?

afremont, I can't recall the shop ever mentioning any sensors just a short somewhere in the wiring. When I left my car with them they couldn't even get the battery jumped (he knew before I even got there to pick it up that it was dead which was odd). I had noticed that for some odd reason all my taillight bulbs were burned out so I'm beginning to question just how legit this shop is. I'm not altogether sure what this is given that I'm not mechanically inclined.
Old 11-28-2012, 09:17 AM
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Re: Complete engine wiring harness

Check the wiring to the 02 sensor, it may be unplugged. Your car will stay in open loop mode all the time with this code set. Your idle problems can be caused by plenty of other things besides a "short in the harness". You need to find a friend with an ALDL cable and the ability to get real info out of the computer. It may become instantly obvious at that point as to what is wrong. Until then, it's guessing.
Old 11-28-2012, 09:37 PM
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Re: Complete engine wiring harness

What about this? Any good?

http://www.ebay.com/itm/GM-OBD1-Scan...ffa868&vxp=mtr
Old 11-29-2012, 07:41 AM
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Re: Complete engine wiring harness

Looks like it should work. I bought mine from www.moates.net I like tunerprort, it's helped me fix my car a couple of times.
Old 11-29-2012, 07:22 PM
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Re: Complete engine wiring harness

I appreciate your help afremont, thank you. Sometimes it feels like no shop wants to touch my bird because it's just new enough that the old mechanics don't understand it unless it's carbed and the newer techs don't want to mess with it because it's old enough they can't hook it up to a computer and fix the problem. Kinda frustrating.
Old 11-29-2012, 07:35 PM
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Re: Complete engine wiring harness

Originally Posted by jiyasa
I appreciate your help afremont, thank you. Sometimes it feels like no shop wants to touch my bird because it's just new enough that the old mechanics don't understand it unless it's carbed and the newer techs don't want to mess with it because it's old enough they can't hook it up to a computer and fix the problem. Kinda frustrating.
I know how that feels x_x. Never thought of these cars as particularly old, but these kids that work at shops don't aren't even mechanics anymore. It drives me nuts. If you can't plug it into a computer, then apparently you can't figure out what's wrong? great.
Gotta say though, I'm starting to realize how old these cars are getting now. when I went to o'reilley and told the girl there I needed an o2 sensor for my 91 firebird, her response was, and I quote "who makes that? Ford, right?" Ouch.
Old 11-29-2012, 07:38 PM
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Re: Complete engine wiring harness

Originally Posted by jiyasa
I'm actually planning on picking this up too next week. thanks for the link on that one. I've been wanting one for awhile now but I thought they were waaay more expensive then that.
Old 11-29-2012, 08:17 PM
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Re: Complete engine wiring harness

You'll be amazed once you see what tunerpro will show you in terms of real-time data from all the sensors. I don't think that most of the shops can do much more than pull the codes.
Old 11-29-2012, 08:30 PM
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Re: Complete engine wiring harness

I've actually had one shop tell me that they couldn't figure it out because "the computer didn't have any codes stored." Your kidding right? A monkey could tell you that.
Old 11-29-2012, 08:33 PM
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Re: Complete engine wiring harness

No prob fervernt, just make sure your connector under the dash is a 12 or 16 pin. I know what you mean about these young kids playing mechanic, it wouldn't surprise me if the guy from my shop called and told me he found the problem was a broken window roller upper just to get me out of his hair lol.

afremont, this aldl cable does more than the ol paperclip trick does? That would be amazing.
Old 11-29-2012, 08:41 PM
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Re: Complete engine wiring harness

the aldl cable actually links up to your laptop, then gives you live sensor readings as you drive the car. at least that's how I understand it. you have to download a program like tunerpro. It logs the data live and tells you exactly what the computer is seeing from the sensors. It does sooo much more than just gives you codes.

Last edited by fervernt; 11-29-2012 at 09:02 PM.
Old 11-30-2012, 02:29 PM
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Re: Complete engine wiring harness

I would seriously question the integrity of the shop that says they can't trace down a short, I have seen the old guy (in his 80's) at Mark's Auto Electric trace down a parasitic draw on my 86 Suburban in a matter of minutes. For Electrical issues try an Automotive Electrician, each time I have taken mine in (there are two in our area that are very good) it has cost me less than 50 dollars and done in same day. They are not mechanics, and they wont fix any mechanical issues, but if you truly have an electrical problem they will find it.

RJMcEachern
Old 11-30-2012, 06:06 PM
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Re: Complete engine wiring harness

Thank you RJ, I'll look into it. While we're still on the subject, what is the obd1 data stream for a 91 firebird?
Old 11-30-2012, 08:07 PM
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Re: Complete engine wiring harness

Originally Posted by jiyasa
Thank you RJ, I'll look into it. While we're still on the subject, what is the obd1 data stream for a 91 firebird?
There is a link to the xdf and adx files for a 92 RS 3.1L V6. I would think that those should work with your firebird.

https://www.thirdgen.org/forums/v6/6...-pro-help.html
Old 12-02-2012, 03:27 PM
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Re: Complete engine wiring harness

I appreciate it, thank you afremont. What exactly are xdf and adx files?
Old 12-04-2012, 09:17 AM
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Re: Complete engine wiring harness

Originally Posted by jiyasa
I appreciate it, thank you afremont. What exactly are xdf and adx files?
XDF files have to do with the bin layout I believe and ADX are for data acquisition from the ECU. There is a wide variety available and you have to have a set of files that matches your car and ECU setup.
Old 12-04-2012, 10:54 AM
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Re: Complete engine wiring harness

Jiyasa, I looked up the company that is selling that cable on ebay, and if you buy it off of their website (reddevilriver.com), you only pay $55 including shipping. with the ebay listing you pay $60 + almost $6 shipping. So you would save around $10 ordering directly from them. Seems kinda shady to have two different prices like that, but there it is. I've heard good things about this company though, so I'll be buying one real soon.
Old 12-04-2012, 03:15 PM
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Re: Complete engine wiring harness

electronic issues can be frustrating to find unless you start in the right places and work logically, there is a chance that you can spend alot of time and money on a wire harness swap and still have the same issue. I would recommend what so of the others have give a good run down of what happens and when it occurs.
Old 12-05-2012, 11:35 PM
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Re: Complete engine wiring harness

I was going to buy a doagnostic tool for my Z28, which was running like crap. Instead, I bought a pronged tool that plugs into the computer plug under the dash- yes I know I could use a paper lip- and it only cost $2.49 at O'Rielly. The code was for the knock sensor and when I checked, the doof that had installed my starter had broken the knock sensor connector and decided not to say anything. That tool might be a quick way for you to get pointed in the right direction. Check all your vacuum lines too- if they are at all rotted, replace them. That can cure a lot of problems with these cars. It sucks that a 'mechanic' these days can only plug in a computer and replace parts until the problem goes away.
Old 12-08-2012, 07:14 PM
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Re: Complete engine wiring harness

Originally Posted by micktroup2
It sucks that a 'mechanic' these days can only plug in a computer and replace parts until the problem goes away.
Which is why I've been saying for a while that these people going to school nowadays should be FORCED to work on OBDI vehicles (of all makes and models, foreign cars are more difficult than ours)... So they actually LEARN something about diagnosis.

Heck, there was a Ford that came into the dealer I was interning at (after I got out of school) that still ran like garbage after the (believe it or not, the guy used to work at the FORD dealer across the street before it closed because the owner was a crook!) mechanic did a full tune up on it. I took one look at it (just a look, didn't touch a thing) and noticed that there was some serious corrosion on the ignition coil's power wire (the wire was pretty much only putting power to the coil through one or 2 strands of wire!). He fixed that and the car ran great. Same thing with a Yukon that had come back for the 2nd time with an issue with the air ride suspension... They replaced the control module TWICE before they tested the power wire for the compressor relay.

Anyways, enough with the rant...

jiyasa, first thing I would do would be to give the engine a full tune up and vacuum test (including replacing the O2S or at least checking if the wire is good) if you haven't done so already. If the base engine isn't right, then the electronics aren't going to be right, and all of the time and money you throw into new sensors, wiring, and testing apparatus will be for nothing if the problem is something as dumb as a bad intake gasket. A high idle is generally an indication of some sort of vacuum leak letting excess air into the engine.
Old 03-16-2015, 12:58 AM
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Re: Complete engine wiring harness

Originally Posted by 6SIX6
I have a harness around here from a 91 camaro V6. I assume they are the same and was taken form a running car
Hi, do you still have it? Do you sell it?
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