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I have an 89 project car I’m working on.
Due to some damage to the front engine harness, I’m hoping to find out what I need to do to disconnect the harness block from the firewall so I can make the needed repairs, then reconnect it.
I’ve googled it and run some searches here, but can’t find anything on it.
The block I’m talking about is the one behind the right side (passenger) cylinder head.
Thanks in advance.
I have an 89 project car I’m working on.
Due to some damage to the front engine harness, I’m hoping to find out what I need to do to disconnect the harness block from the firewall so I can make the needed repairs, then reconnect it.
I’ve googled it and run some searches here, but can’t find anything on it.
The block I’m talking about is the one behind the right side (passenger) cylinder head.
Thanks in advance.
That's an assemble and needs to be removed 'whole' bringing the inside harness & connectors out through the firewall if you actually need to do repairs that enter the cabin. There are 5 harness connectors and a vacuum connector. The connector(pass-through) is retained by 2 rivets I believe. You should be able to see how it's retained. I have an '89 M6, C68(ATC) harness complete if your car is an M6//C68. Mine has no damaged connectors. A correct harness would need to be either C60 & M6, C60 & A4 or C68 & M6 or C68 & A4.
There are a number of '89 engine harnesses on eBay that you can use for an idea of what grommet/pass-through looks like. You can NOT separate it and reuse easily!
Removing the harness at the left side is very easy. One bolt holds the engine harness and forward lamp harness to the C100.
Do you have a correct FSM?
I can send you an image of my grommet/pass-through if you like. Drop me an email.
8A-201-8 Fig A will give you a very good idea of what needs to be removed with the harness from the inside.
This is NOT an '89 but it's similar to what's internal to that 'pass through' on your '89
Thanks for the information. I do have a fsm for 89 and looked up the illustration.
If I’m seeing it correctly, the harness doesn’t actually “unplug” at that point but instead it’s just a pass-thru for the uninterrupted harness.
It looks like I’m going to have to get in there and make repairs the good old fashioned way.
Next question, where can I get self-sealing shrink tube that’ll hold up?
Thanks for the information. I do have a fsm for 89 and looked up the illustration.
If I’m seeing it correctly, the harness doesn’t actually “unplug” at that point but instead it’s just a pass-thru for the uninterrupted harness.
It looks like I’m going to have to get in there and make repairs the good old fashioned way.
Next question, where can I get self-sealing shrink tube that’ll hold up?
Does NOT 'un-plug' is correct. What is wrong with your harness?
What do you consider 'the good old fashioned way'?
The “good old fashioned way” is leaning over the car, working within the tight confines available behind the valve cover while stripping, soldering, shrink-tubing the connections. At the spry young age of 67.
What happened to the harness is a result of not only my own gullibility, but the extended length prank of a jack-azz assuring me he’d done his son’s car the same way. I let myself be convinced to cut the harness to clear the area so I could run the harness of a stand-alone FAST system in its place. But now I’ve reconsidered and would like to try to get chip made for my tune.
I then found out that I was fed a bunch of Bull and became the butt of a number of jokes about it.
That’s what happened.
The “good old fashioned way” is leaning over the car, working within the tight confines available behind the valve cover while stripping, soldering, shrink-tubing the connections. At the spry young age of 67.
What happened to the harness is a result of not only my own gullibility, but the extended length prank of a jack-azz assuring me he’d done his son’s car the same way. I let myself be convinced to cut the harness to clear the area so I could run the harness of a stand-alone FAST system in its place. But now I’ve reconsidered and would like to try to get chip made for my tune.
I then found out that I was fed a bunch of Bull and became the butt of a number of jokes about it.
That’s what happened.
You cut them all? That sucks! Is your car maybe an M6 w/C68?
The wires to the coolant temp sensor on the front of the intake, the diverter valve, A/C compressor, and a couple others are still intact.
IIRC, what was cut was the two injectors before they branch out to each four separates, and the EGR. But I need to actually get into the box of removed wires to check the labels.
Yes, it’s a 6-speed. Not sure about C68.
The interior is LOADED with stuff so it’s a bit tough to get to the option codes.
Under the hood @ the AC box there's either a blower resistor or an 'AC Control Module' with a 4 terminal square and an adjacent 2 terminal connector. See the 8A-202-4 for connector image.
I have an M6 - C68 engine wiring harness that's complete with nothing cut. Would it be easier (I'd think so) to replace the entire harness vs attempt the splicing repair that you're considering?
I'd think regardless your decision it would be much easier to remove yours complete and repair 'on a bench' vs attempt the repair with the harness/grommet in place in the car. The downside of a repair I'd think is also the number of 'splices' that are contained in that wire bundle. FSM hints maybe 5 or more.
You’re right, there’s a lot of splicing to be done, so yes, I’d be pretty interested in the harness. The biggest apprehension I have is just what I have to do to change them out. Besides my age, I’m a good sized guy, 6’3”/260 lbs. So getting under the dash isn’t as easy as it once was.
How much do you want for the harness?
You’re right, there’s a lot of splicing to be done, so yes, I’d be pretty interested in the harness. The biggest apprehension I have is just what I have to do to change them out. Besides my age, I’m a good sized guy, 6’3”/260 lbs. So getting under the dash isn’t as easy as it once was.
How much do you want for the harness?
I sent you my email in a PM - to disconnect the harnesses from the ECM and the other connectors I wouldn't think requires an extensive time under the dash. Have you ever removed the ECM in this car?
Last night, I was looking at the “Plug” and there’s a screw on either side of it, plus the clips to unfasten. I’m thinking those are there for a security type of redundant retention.
As for under dash, I’m wondering if this is a simple disconnect or if there are wires in this that also run to other plugs needing to be re-pinned.
Last night, I was looking at the “Plug” and there’s a screw on either side of it, plus the clips to unfasten. I’m thinking those are there for a security type of redundant retention.
As for under dash, I’m wondering if this is a simple disconnect or if there are wires in this that also run to other plugs needing to be re-pinned.
Nothing should need 're-pinned' anywhere. Just disconnect and reconnect under the dash.
I would just add that in addition to the wiring harness itself, that vacuum line that WVZR-1 mentioned up top is really important. It's the source of engine vacuum into the HVAC system for vacuum servo / valve controls and the A/C will not work without it being absolutely right. So while you're paying attention to all the wires, make sure you've got that black plastic vacuum tube that's interwoven into the harness clean and correctly routed. It will end up here at the arrow - to that Tee fitting...
I would just add that in addition to the wiring harness itself, that vacuum line that WVZR-1 mentioned up top is really important. It's the source of engine vacuum into the HVAC system for vacuum servo / valve controls and the A/C will not work without it being absolutely right. So while you're paying attention to all the wires, make sure you've got that black plastic vacuum tube that's interwoven into the harness clean and correctly routed. It will end up here at the arrow - to that Tee fitting...
Thanks for the input!
Yes, I’ve kept that in mind, and will double check it’s welfare when I get in the garage.
Thanks.
I would just add that in addition to the wiring harness itself, that vacuum line that WVZR-1 mentioned up top is really important. It's the source of engine vacuum into the HVAC system for vacuum servo / valve controls and the A/C will not work without it being absolutely right. So while you're paying attention to all the wires, make sure you've got that black plastic vacuum tube that's interwoven into the harness clean and correctly routed. It will end up here at the arrow - to that Tee fitting...
Under the hood where your 'blue arrow' is directed I'd think that should be a 'female' elbow. Correct?
Seeking front harness info
