Splicing in a main engine wire harness at the firewall, need wiring diagram?

Yep, here are the engine wiring harness wiring diagrams and I have included a guide to help with the testing if you need it:

https://www.2carpros.com/articles/how-to-check-wiring

Check out the images (below). Please let us know if you need anything else to get the problem fixed.

Hi,

I would be happy to help. There is one problem, I have no idea which schematic you need. Are the wires in question-related to power distribution, powertrain management, controller networking, or something different?

Let me know which you feel would help the most or if you want them all.

If you look below, I listed the circuits I have schematics for.

Let me know which you want, and I will get them to you.

Take care and Happy New Year,

Joe

See pics below.

All of them. The thickest part of the harness where all the wires go through the grommet into the firewall into the passenger compartment behind the heater core. And goes to the interior fuse box.

Hi,

Okay, here we go. I don't think I ever copied so many schematics. Don't be overwhelmed. Now, other than the first pic, which is for the power antenna, all others have a heading on the first page.

I had to cut each page in half to make them readable for you. But I did overlap them for you so you can follow from one to the next.

Let me know if this helps or if you have other questions.

Take care,

joe

See pics below.

Thanks guys. Another question. Is it a safe bet to say that all of the ground wires will be solid black? Can I go ahead and wire the solid black wires and be okay?

Hi,

Yes, the grounds are black. I don't know how, but I missed the ground circuits. I attached them below.

Let me know if this helps or if you have other questions.

Take care,

Joe

See pics below.

Thanks Joe.

Can you tell me how the dash comes out? I've read the manual and can't find a video. I've taken all the nuts and bolts out and the cross bar that runs behind it is loose. Bit I am missing something because I cannot get it out. Everything is loose but will not come out.

Hi,

I attached the directions from my manual below. There is a list of things that need to be removed and then a section that shows you where the nine bolts and one nut are located.

Take a look through the directions and let me know if you have questions.

Take care,

Joe

See pics below.

The C nut? Does it run through the firewall? Then that's the one that is holding me up. I've got the same manual. But I've removed all the clips and nuts and it's the C I think is holding it in.

Hi,

You should be able to just remove the nut. The stud it's on will be attached to the firewall. Is the nut removed?

Joe

Pretty sure it is. I will take a picture when I get home and post it.

Is it possible that there is some kind of adhesive holding the crash pad in? I have removed every bolt and clip from the pad, and I've even unbolted the cross member from the frame, and it still won't come out. Like something is holding it in the middle somewhere! Somewhere along the windshield.

Hi,

To the best of my knowledge, there is nothing like that near the windshield. Make sure there isn't a wiring harness attached.

Let me know.

Joe

I will and I will attach a picture when I can. It's always dark by the time I get home from work.

Are there bolts under the defogger in the front by the wind shield?

Hi,

There are nine bolts and one nut that hold it in place. Were you able to locate all of them? As far as behind the defroster, there are guide pins. It's possible it is held up by one of the pins.

Let me know.

Joe

I finally got the crashpad out. I wound up just removing the entire wire harness from the engine to the interior. I went to the pull a part and got the entire harness from another Elantra and I am in the process of wiring it in . Just seemed easier than the route I was going. The car will run again. There's been a lot of nay sayers that I'm going to prove wrong. Won't be too long and she'll drive again.

Hi,

Thank you for the update. I like your positivity, and it will run again. Let me know how things turn out. I'm interested in knowing.

Also, let me know if I can help in any way.

Take care,

Joe

I do have a question. Same car but different problem. After the fire. A few months passed. Car hasn't run so motor was cold. We had a hard freeze and the next morning I went out to work on the car and I saw a puddle of oil under the engine that wasn't there before. Wanted to know your thoughts on it. Thanks again .

Hi,

The only thing I can think of is if an oil cooler on the engine (if it has one) cracked or something on the engine.

Do me a favor. I'm interested in solving this, but I need you to start a new thread. We try to keep the posts specific to one topic, so it is more helpful to others. I hope you understand.

Here is the link to start a new post. Just copy and paste your new question and we'll get to it.

https://www.2carpros.com/questions/new

Again, I hope you understand.

Take care,

Joe

Okay. Here we go. I've hooked up the harness and connected the ignition. Got a door light and a brake light that came on. My question is what are the chances that when the wires melted something arched and fried the computer or would the starter still spin over?

Hi,

If there was a short, certainly the body control module could have been damaged. Do any of the other electrical components work properly? Also, you mentioned the starter. Is it working correctly?

I attached the body control module schematic below, so you have it as a reference.

Let me know.

Joe

See pics below.

I haven't hooked up everything as of yet. Only the ignition and key switch. And the a few grounds. As for the starter I bought new from rockauto. I will test it just for giggles to make sure it works.

Hi,

Okay. Let me know what you find. Also, let me know if the starter works. LOL It should. I've had good luck with them over the years.

Take care,

Joe

I went through the fuses and 3 were blown. 1 for the hazard and 2 more. I replaced the 10-amp fuse for the hazard and the fuel pump kicked on and wouldn't kick off. Until i pulled the fuse out. Weird. But it still wouldn't turn over. I ran out of light so I will check the starter tomorrow and let you know what happens. Also, I opened the computer to check the board. I didn't see anything that looked burned or melted. It looked good to me. It's under the dash tucked away in the upper left corner behind the fuse box, correct? Metal box that the harness connects to?

Hi,

According to the manual, it is behind the AC switch panel (center dash).

Let me know what you find.

Joe

Starter is good. I've got dash lights and a taillight on. The chimera for the keys on as well. Does my Elantra have an anti-theft system in it? There is a black box with antenna behind the A/C controls with etacs. Is this an anti-theft module? I have a regular key in ignition. Would that cause the starter not to turn over? All this is beyond my pay scale.

Hi,

It could have an alarm system. Also, the ETACS is the BCM on this vehicle. Have you tried scanning the can-bus at this point? It may point you in the right direction. Also, if it has anti-theft, the starter will still engage but the engine won't start.

See pics below.

Joe

I put the OBD scanner on, but it'll only go to 96 % then tell me it's communications error so I've been slowly hooking up everything. But it still only goes up to 96% so I think I'll have to get everything else hooked up then I'll try again and keep trying until something gives. I'm closer everyday but just can't get over that hump and get it started. I'll keep you posted and if I have any questions I know where to turn. Thanks for all your help so far. Between you me and Google I'll have this car back on the road in no time.

Do any of you guys have a illustration of the harness layout? Where tall the connectors will go? How it should look? Oh, and I got it to turn over. It would've fired up if I had the throttle body on it.

Hi,

Normally, the manuals don't provide harness routing. I did find one for under the dash and have attached it below, but it is vague and difficult to follow. They show connector numbers but provide no legend. Ugh!!!

I'm glad to know you are making progress. Stay in touch.

Take care,

Joe

See pic below.

I've looked and looked all over the web and can't find a good illustration of the layout. On my ignition there are 4 connections, but I can only find 3 to plug in. My fuel pump is not kicking on now. I thought that it might be the 4th connections I can't find. The illustration that you attached really doesn't show where everything hooks up.

Hi,

Let's try narrowing it down. If I look for specifics, I usually can find things. When you say on your ignition, there are... are you referring to the ignition switch or something other?

As far as the ignition switch is concerned, take a look below and let me know if I am on the right track.

Take care,

joe

See pic below.

I found out what I was looking for. I went to the junk yard and took one apart a took some pictures. Don't know if the fuel pump will kick on because it got dark on me. I will update this evening.

Update: I tested the fuel pump relay and it's good. I ran wires straight to the battery from the pump and it came on. It still will not come on with the key. Is it possible I fried the ECM while hooking up the wire harness or could it still be ground issues?

Hi,

If you ran power from the battery and it ran, the ground has to be present. If you jump pins 30 and 87 at the relay, does it come on?

Joe

I have not jumped those yet. I hooked up power to the relay and put my meter on it too. The relay clicked. But I didn't jump them in the socket. so I'll try that tomorrow after work.

Hi,

Sounds like a plan. You shouldn't need to supply power. It should be present.

I'll watch for your findings.

Joe

I put a jumper wire between the 30 and 87 and nothing happened. I hooked my obd scanner (little cheap one) up and it only throwing 1 code. P0885 which is TCM power relay. Would the cause the fuel pump not to kick on. And is the TCM the same and the ECM?