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How to fix a wiring harness using Plasti-Dip.

BlueSupreme

CEG'er
Joined
Nov 29, 2017
Messages
56
Location
Tolland County, Connecticut
I have a 1997 Ford Contour Sport that hasn't really had any harness issues while it was in use but I noticed how bad it was getting and found out about the Owner Notification a little late. As with others I contacted my local ford dealers and all the harness's have been discontinued. I would go to a junk yard and pull one but I am pretty busy and don't want to go through the effort of trying to pull a wiring harness from the tight engine that is the duratec in a car that is the contour. I have found another way to at least temporarily fix the stock harness from a recommendation by an employee at pep boys. Things you will need: Plasti-Dip, lots of electrical tape, wire loom, (optional) wire and ford connectors if they need to be replaced or fixed.
1: Your going to want to carefully pull the wiring harness off the engine, my engine is out so it make the job easier, or cover the engine with something as to not plastic-dip it.
2: Fix any connectors or broken wire on the harness with, go wire by wire as to not mix any up, remove as much wire loom, electrical tape as needed to repair.
3: Break away any insulation that is bad or loose, you can also keep the cracked insulation but plasti-dip may not seal the wire as well. You should remove the wiring loom to fix as much as you can.
4: Pasti-dip away, I've learned this stuff dries pretty quickly, the first couple of layers probably won't cover the entire wire but create a foundation to build off of. You are essentially making a new insulation around the bare wire, make sure you don't miss any spots like where it meets at the connector. Spray any cracked insulation that would be hard to fix like at the computer connector, also spray the plasti-dip any hard to reach areas.
5: Allow for a day or two to dry and inspect to make sure you've hit every spot. If needed electrical tape the wires you have just plasti-diped, then put the stock wire loom back over the wire and electrical tape that.
6: Use new wire loom to go over the stock loom you have just put back on, make this longer then stock and have it go all the way to the connector then electrical tape that loom.
7: Reconnect everything
Things to remember! While pasti-dipping the wire make sure the wires get separated as to not touch. Don't use the pasti-dip conservatively, apply as much as you think will provide a good amount of insulation, this also goes for the electrical tape which should be tight as to seal heat and water out. A good suggestion is to try it out on a test piece of wire and get used to a good technique.

Pasti-dip re-insulates the wire and keep the water and moisture out while the electrical tape and wire loom keep the heat out as well as protects from vibrations. Liquid electrical tape could also work, I have thought about using flex seal products too but have not tried it.

I do not know how long this fix will last, but I do know that it is better than using just electrical tape and or leaving the wire open to the elements. I have not tested it on an engine that is currently in use but will hopefully soon. It is always a better solution to get the harness fixed properly by professionals or rewiring with proper experience and knowledge of the harness. I am trying to provide an alternative way to fix this common issue with my findings, I will provide images at a later date as well as how well it is performing.

Found a good example of what my harness looked like on a Porsche forum: https://rennlist.com/forums/porsche-cayenne-forum/733521-brittle-wiring-insulation.html
 
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is your car an mtx or atx? if its an mtx my harness conversion will work on your car. message me for details and pricing.
 
I have a 1997 Contour Sport with a Duratec V6 with an MTX that is having this issue, I did this as a suggestion to others who are in my situation or want to prolong their faulty harness as long as they possibly can. I probably should have clarified my situation but I am currently restoring this car and on top of that I just bought a 1999 Contour SVT (T Green) which also set me back a little on what I wanted to fix on the sport. Plus for me all that I'm paying for is the plasti-dip since I had left over wire loom from my stereo upgrade and had a 10 pack of electrical tape from harbor freight I bought a while back. Regardless $10 on amazon gets you 100ft of loom, $5 gets you a 10 pack of tape at harbor freight and then the price of the plasti-dip.

I also want to keep the SVT as stock as possible since its "collectable" according to the certification sheet, as for the sport I'm planning on upgrading performance on that later down the road since it is a car I don't have to keep 100% nice. Meaning I am planning on finishing the sport without doing anymore upgrades but pull the engine again later down the road for the upgrades after the SVT gets finished. So if I can pro-long the harness to that point, then I will replace it.

FrancisPennysac, is there anything in particular that causes this or does it just happen overtime, also wouldn't the many layers of plasti-dip prevent this as well as the tape and wire loom? Anything you'd recommend using that would be more effective for the amount and price?
 
and yes I agree this isnt a good idea to plastidip wiring.. its a cheap work around that is not as good as replacing the wire totally or swapping out a harness. When you cut corners bad things happen.
 
No Title

and yes I agree this isnt a good idea to plastidip wiring.. its a cheap work around that is not as good as replacing the wire totally or swapping out a harness. When you cut corners bad things happen.

satya_svt98 In the red I've stated that it was better to get it repaired, forgot to mention the option of being swapped, but the point was to share another option to the common faulty wiring harness issue, even though temporary and "cheap". Some people may not have the option of swapping or rewiring their harness, while I am skilled enough to repair the harness myself, I just don't have the time and money to, as I am a senior in high school who is just trying to fix his mom's old daily to be used as his own.

Also what I'm doing isn't necessarily cheap work, if done right the harness will be better off then factory having more protection, I would rather rewire the harness myself but I am trying to get the car finished before Christmas 2017 having other repairs and maintenance still needed to be done. That said, I agree and have full intentions to replace this harness later down the road but I needed something that would hold me over till I can start and finish the 99 SVT. (I don't have the space and equipment for two engines to be pulled at once.)

I'll add these pictures in order to show what I've done in a couple minutes of putting little effort into it, all pictures except the main loom to the computer had bare copper wire at the connectors. Not sure if it will last but I do know its better off then being bare copper. I am not done yet but just wanted to show what my progress was so far.
 

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Ideally, it is best if the wiring was replaced with new wire. It is possible to get new wiring and make your own harness, but that takes time and it is technical in nature. I have done it, and it takes a lot of time to do it correctly.
 
I just dont know about doing a write up for a fix that is a) not the best option b) have to have certain skills to pull off c) something that multiple are saying not to do. Any other newb with a engine harness problem should focus on either getting one rebuilt, swapping a good harness on or buying an updated fixed harness.
 
I just dont know about doing a write up for a fix that is a) not the best option b) have to have certain skills to pull off c) something that multiple are saying not to do. Any other newb with a engine harness problem should focus on either getting one rebuilt, swapping a good harness on or buying an updated fixed harness.

The way these cars are so touchy with electrical issues, particularly ECU issues, getting the wiring harness rebuilt or installing one that is good is the best option. Given that both you and I saw the ECU being so touchy with millivolt data, if ANYTHING is not right, it throws everything off kilter, particularly sensor data. If the ECU is expecting .0211 MV from an oxygen sensor and if it is .0201, it can set the CEL for that sensor.
 
Not sure where the fuss is on this. He stated this is what I did, it's not the best option but it is something that can be done. I'll post back on my results. It's temporary and cheap. Guide the kid not destroy him.
 
Not sure where the fuss is on this. He stated this is what I did, it's not the best option but it is something that can be done. I'll post back on my results. It's temporary and cheap. Guide the kid not destroy him.

We are trying to educate him on the best solutions that offer little problems later on. We know the car well enough and doing something that is not good will result in major work later on.
 
No Title

The way these cars are so touchy with electrical issues, particularly ECU issues, getting the wiring harness rebuilt or installing one that is good is the best option. Given that both you and I saw the ECU being so touchy with millivolt data, if ANYTHING is not right, it throws everything off kilter, particularly sensor data. If the ECU is expecting .0211 MV from an oxygen sensor and if it is .0201, it can set the CEL for that sensor.

Thanks for the information, I enjoy seeing these types of replies because it is constructive criticism, you give your opinion but you explain in detail with facts why it is the better option. I had a feeling these car computer systems, as "dated" as the contour is compared to what's coming out today, use very touchy data readings for certain sensors. I am a ham radio operator so I have worked on some electronics before, I will have to eventually swap the harness because I don't have the time to rewire my current one. Basically I am aware of the sensitivity, I DO have the skill to rewire the harness myself if I had the time, and I don't have the money to buy a new one right now.

(later edit)
Thanks squeek, at least someone understands my purpose of posting this. As of new years day I have the engine in the car and even ran the starter to make sure the oil pump primed itself and the engine had good compression. I had a few issues over the past few days involving a few connectors that were broken after the engine was pulled that I had to replace. When I did this I noticed that the cam and crank connectors were shorted, the ones I replaces so far, and started checking more connectors to make sure that it was an isolated issue. Unfortunately my quick repair was a little too quick being so determined to get the engine back in on New Years Eve that I didn't get every wire. This plastidip fix still worked really well, in fact I'm a little surprised the computer even came on with how many shorts I found probing sensor connectors. The moral of the story is that plastidip is better for spots like bare wire right at a connector, but if doing a whole harness you really got to break open every part of a loom and get a good amount of layers in. That was my mistake, not enough layers and I didn't open up every part of the harness. I feel better now that the engine is in and even cranked but I do have to pull the harness out and rewire it, all due to me rushing.

I guess its all part of the learning process. At least the engine looks good...

Oh and this engine has 223,150 miles on it, ONLY engine oil used in it was Mobil 1 Synthetic, my dad and I replaced oil pump and timing chains but we really didn't have to because it looked like it had come right from the factory with about 1,000 on it. Amazing how a couple extra bucks per oil change makes an engine look like brand new after 200k, I'll never settle for less! What a shame, the only thing preventing this from running right now is the harness.
 

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Thanks for the information, I enjoy seeing these types of replies because it is constructive criticism, you give your opinion but you explain in detail with facts why it is the better option. I had a feeling these car computer systems, as "dated" as the contour is compared to what's coming out today, use very touchy data readings for certain sensors. I am a ham radio operator so I have worked on some electronics before, I will have to eventually swap the harness because I don't have the time to rewire my current one. Basically I am aware of the sensitivity, I DO have the skill to rewire the harness myself if I had the time, and I don't have the money to buy a new one right now.

(later edit)
Thanks squeek, at least someone understands my purpose of posting this. As of new years day I have the engine in the car and even ran the starter to make sure the oil pump primed itself and the engine had good compression. I had a few issues over the past few days involving a few connectors that were broken after the engine was pulled that I had to replace. When I did this I noticed that the cam and crank connectors were shorted, the ones I replaces so far, and started checking more connectors to make sure that it was an isolated issue. Unfortunately my quick repair was a little too quick being so determined to get the engine back in on New Years Eve that I didn't get every wire. This plastidip fix still worked really well, in fact I'm a little surprised the computer even came on with how many shorts I found probing sensor connectors. The moral of the story is that plastidip is better for spots like bare wire right at a connector, but if doing a whole harness you really got to break open every part of a loom and get a good amount of layers in. That was my mistake, not enough layers and I didn't open up every part of the harness. I feel better now that the engine is in and even cranked but I do have to pull the harness out and rewire it, all due to me rushing.

I guess its all part of the learning process. At least the engine looks good...

Oh and this engine has 223,150 miles on it, ONLY engine oil used in it was Mobil 1 Synthetic, my dad and I replaced oil pump and timing chains but we really didn't have to because it looked like it had come right from the factory with about 1,000 on it. Amazing how a couple extra bucks per oil change makes an engine look like brand new after 200k, I'll never settle for less! What a shame, the only thing preventing this from running right now is the harness.
WEC
Technically these cars are not as dated as some think. The touchiness is how the ECU is programmed and its settings. I know one of the engineers who was responsible for this and in his later work, he was setting the system up quite narrowly and still does. He was stating in a class I took that the settings were more for clean emissions and Ford, and later Hyundai wanted him to set it like that to clean up the environment.

BTW, I found these cars touchy with misfire codes and cat efficiency codes, and in the UK they issued a TSB on this to change the gap of the sparkplug from .051 to .039 to keep the misfires from damaging the cat.
 
BTW, I found these cars touchy with misfire codes and cat efficiency codes, and in the UK they issued a TSB on this to change the gap of the sparkplug from .051 to .039 to keep the misfires from damaging the cat.

In the US there was TSB to reprogram the PCM widen the range before it set the P0420/P0421 codes. I do not recall any change in plug gap.
 
In the US there was TSB to reprogram the PCM widen the range before it set the P0420/P0421 codes. I do not recall any change in plug gap.

The reason why the cat codes is touchy is because the intake manifold was designed wrong and does not match the exhaust system on it.

I did see Terry Haynes saying something that the UK did issue a TSB (not here in NA) on narrowing the gap to .039 or 1 mm. I have my plug gap set at .042, which I notice better performance and less emissions than with a gap of .052.

On the exhaust side, changing that completely to a 2 1/4 inch minimum with dual axle back exhaust or 2.5 inch single exhaust makes the cats happier,
 
No Title

Ok an update on the harness,... the majority of the wire is now replaced but I still have to do some more connector repairs include one which I believe is to a knock sensor:shrug: even though most auto store websites say that the 1997 contour with the V6 doesn't have it. Regardless I know its the replacement for that connector, my dad also works at Pratt & Whitney so he was told about this "tephlon" like tape that sticks to itself and is rated at 500F that the shop uses on their wiring for the jet engines. Tape by Nashua. I'll include a few pictures of the state of the wiring harness.
 

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