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Best way to repair damage from taps on wires?

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23 May 2020
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SF Bay Area
I’ve been tracking down the cause of some weird behavior and managed to isolate it to a potential bad connection on a couple wires at the ECU. My car had a bunch of t-taps on wires at the ECU when I bought it. You can see some of the little cuts on the wires here. At least one of these is causing intermittent issues

7053C63F-BB4E-4DF4-9DF4-83F3C51426AC.jpeg

I’m looking to repair all these and curious if anyone has any really clean approaches to repairing these. I’d love to not cut them, just strip a little insulation, put some crimp on them and shrink wrap. But I can’t find anything nice to crimp without cutting the wires. Any butt connectors small enough (probably) don’t fit over the ecu pins.

Seems like I have a couple options

* strip some insulation, solder, shrink tube
* cut them at the damage, crimp with some really small butt connectors (I have some 24-20awg connectors coming), shrink tube. Leaning this way

Anyone have a super nice way to fix these?
 
My initial reaction was cut the wire, splice with an uninsulated closed barrel crimp (Panduit makes some nice small ones) and then insulate with heat shrink. That makes the most compact repair. Any closed barrel crimp that fits the wire gauge correctly will not fit over the wire terminal. If the damage is close to the plug body you may have to de pin the terminal in order to crimp the splice - my ratcheting style crimper would be too big and clunky to crimp the repair on that damaged yellow wire close to the plug.

If just the insulation is damaged; but, the conductor strands appear intact then I would be inclined to de pin the terminal and slide a high shrink ratio piece of heat shrink over the terminal to the repair site and shrink to fit. In fact, even if one or two strands were broken I would probably use this approach because a butt splice with heat shrink jacket close to the plug body has the potential to create crowding / chaffing with the adjacent wires.

Don't use solder with a conventional twist of the bared conductor ends. In order to get a good conventional solder joint you have to get the copper strands hot enough that solder will end up migrating up the strands creating a rather solid inflexible length of wire prone to cracking.

There are some low temperature solder filled pre insulated splices that some people claim to have had good results with. I think you can solder and heat shrink in one step with a high temp air gun. I have no direct experience with those types of repairs; but, it might be an option. I think they tend to be bigger than the best small closed barrel butt splices. I think they require cutting the wire to make it work because the correct 'barrel' size will not fit over the de-pinned terminal.

I hate those miserable squeeze type T taps.
 
Thanks guys, yeah it seems like the butt connector method seems like the best option. Thanks for the specific brand recommendations.

I’ll probably avoid the heat gun solder connectors, I definitely want to keep solder out of there
 
I guess I’m basically looking for double sided open barrel terminals. Like this but with the crimpable part on both sides. Anyone know if these exist?

View attachment 174852
There is this


Wire sizes look to be in correct range. I don't know what kind of crimping tool it requires.

or this


Problem is, the smallest size for the second one is #12 awg.

When searching Digi Key, make sure you select the 'in stock' filter. Otherwise, you might selecting a non stock item with a minimum order size of 5000.
 
My normal go to is a solder sleeve, but those are pretty cramped quarters. Might or might not have enough room.

These are mil/aviation spec and what I used in the Navy. You can get cheaper ones, but the shrink tube material isn't as durable and the solder quality isn't as good.

You can use a small heat pen for tight spaces to create a more directed heat area. I've had good success with this type of work in my day job.


 
How upset were you when you found all those wire splices? I have found wire splices on my car in nearly every place I have looked (ECU, trunk, under both sides of the dash, under the hood, etc). I am terrified to pull the radio/speakers out because of what that probably looks like.
 
My normal go to is a solder sleeve, but those are pretty cramped quarters. Might or might not have enough room.

These are mil/aviation spec and what I used in the Navy. You can get cheaper ones, but the shrink tube material isn't as durable and the solder quality isn't as good.

You can use a small heat pen for tight spaces to create a more directed heat area. I've had good success with this type of work in my day job.


The TE Connectivity version of those were the solder sleeves that I was thinking of. You do have a bit of a challenge when sorting through the zillion options because a lot of them are specialized (attaching grounds to cable shields ....) and not necessarily intended for splicing wires together. The data sheets are also a little opaque because they specify wire sizes in circular mils (area) rather than AWG which most normal folk use. If somebody sold them locally I might have tried them.
 
These are mil/aviation spec and what I used in the Navy. You can get cheaper ones, but the shrink tube material isn't as durable and the solder quality isn't as good.

Good to know on the solder sleeves. I'm still a little nervous about using solder for these wires, but If it works in Navy applications, it's probably fine for the car.

How upset were you when you found all those wire splices? I have found wire splices on my car in nearly every place I have looked (ECU, trunk, under both sides of the dash, under the hood, etc). I am terrified to pull the radio/speakers out because of what that probably looks like.

Yeah, it was annoying when I pulled off the top panel for the first time. There were like 6 taps in there. They were all going into some old defi controller that lead nowhere :/. Fortunately these were the only ones I found in the car (so far), and I've been in a lot of the wiring. It has lots of other crazy wiring going on though, like the alarm is a multi week project if I wanted to extract it....
 
I went down the rabbit hole of looking at TE splice terminals on their website, and @Old Guy's point applies:

You do have a bit of a challenge when sorting through the zillion options because a lot of them are specialized (attaching grounds to cable shields ....) and not necessarily intended for splicing wires together.

Too many options! Do they fit? I dont know! Am I willing to wait for the 4-6 week lead time? No!

I'm still stuck on not cutting the wires if I can get away with it. I emailed Joe at cycleterminal about how he would fix it and if he had any splice terminals. Turns out he does sell them, and he has them in stock http://www.cycleterminal.com/splice-terminals.html. Yay. I bought a bunch and they will be here by the weekend. I also bought some from amazon just in case, we'll see about the quality of those....
 
Another option is to de-pin the connector, cut off the bad wire, crimp/solder on the new wire and put a fresh pin on the end and slot it into the plug again.


I haven't looked but there might be some instruction for this in the manual. I've done this a few times when adding new sensors/Hondata.

I've used the pins from this shop which is OEM stuff. Not sure if Acura sells ECU pins or not. The guys at H-A are really good so if you want to go this route you could give them a call.

 
Cycle Terminal can also probably set you up with replacement terminals if you go down the path of re terminating.


The shop owner is also an NSX owner and has been able to supply correct replacement terminals and plugs for the NSX. They have a supply of crimp tools and de pinning tools.
 
Cycle Terminal can also probably set you up with replacement terminals if you go down the path of re terminating.


The shop owner is also an NSX owner and has been able to supply correct replacement terminals and plugs for the NSX. They have a supply of crimp tools and de pinning tools.
Tagging him here: @Scrapdog2grand
 
I offered him a couple options similar to old guy. Most of those with damaged insulation I'd de-pin and put a piece of shrink over it. I had the same problem on one of my NSXs, looked like one of the previous owners the had an aftermarket controller spliced in at one point and quite a few wires were damaged close to the connector housing.
I'm not a fan of soldering that close to the connector due to the solder wicking, also not a big fan of the butt connectors for an application like this but they do work great.
So for me a few got covered with just shrink, a few were spliced together (open barrel splice below) with then a piece of shrink tube, and a few got a spliced length of wire with a new terminal.

1664983907235.png1664983856068.png
 
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Another option is to de-pin the connector, cut off the bad wire, crimp/solder on the new wire and put a fresh pin on the end and slot it into the plug again.
Yeah I could repin it at the ECU, but I'd like to keep the OE colors and things, and not have to pull the wire if I were to repin with no new wire.

FWIW, I do have a bunch of ECU plug terminals and have added a couple sensors with them. The ECU (and Honda OBD1 in general) uses the TE/AMP Multilock system. 070 for the big wires and 040 for the small wires

* 070 terminals: https://www.mouser.com/ProductDetail/TE-Connectivity-AMP/776129-2?qs=Ptd7IYAYwrVwwa6f6Dzgwg==
* 040 terminals: https://www.mouser.com/ProductDetail/TE-Connectivity-AMP/776181-1?qs=MzdiiTx5rGwPIbBoMeAVKw==

It's cool cause you can get multilock plugs in other formats. So if you needed to like add a VTEC controller, you could unpin at the ECU plug, put the ecu plug pin into another multilock plug, then make a little patch harness out of multilock connectors for your controller. No taps, no soldering, only OE pins and connectors. My F ecu plug is this right now for VTEC cause the AEM series 1 doesnt have an F plug...

I think I'm sold on the splice terminals for now, cant wait to have all these fixed! Thanks @Scrapdog2grand for being super responsive and helpful!
 
I offered him a couple options similar to old guy. Most of those with damaged insulation I'd de-pin and put a piece of shrink over it. I had the same problem on one of my NSXs, looked like one of the previous owners the had an aftermarket controller spliced in at one point and quite a few wires were damaged close to the connector housing.
I'm not a fan of soldering that close to the connector due to the solder wicking, also not a big fan of the butt connectors for an application like this but they do work great.
So for me a few got covered with just shrink, a few were spliced together (open barrel splice below) with then a piece of shrink tube, and a few got a spliced length of wire with a new terminal.

View attachment 174880View attachment 174879
That is a nice open barrel crimp. To save me the search effort, whose product is it and what crimping tool did you use? I don't need any at the moment; but, I can see that they would be real handy to have on hand. I don't like doing in-line taps; but, if I have to, that second photo with a piece of heat shrink would be the way to go.
 
Separate the damaged wire(s) needing insulation repair then squeeze hot glue over the damaged part. When the glue sets it will insulate the wire....IF you do this with a couple good wires nearby the good wires will act like a splint and give strength to the damaged wire.
 
That is a nice open barrel crimp. To save me the search effort, whose product is it and what crimping tool did you use? I don't need any at the moment; but, I can see that they would be real handy to have on hand. I don't like doing in-line taps; but, if I have to, that second photo with a piece of heat shrink would be the way to go.
These are TE Amp brand splices. that was 18 gauge wire, the brass PN 40509, that tin plated terminal is no longer made. 41975 is a little smaller and perfect for splicing some of the smaller wiring together.

This tool below is from White products, made in the US by Sargent tools (good place to order tools and some Delphi parts, operated by all women) Many other places will have this also, waytek wire maybe. But it works great for these smaller splices.
The larger splices require a slightly wider tool and die, I use the Hero BL255 out opf Japan. iWiss makes much cheaper tools that will work well for large splices, but they're not gonna be the same quality as the Hero.
1665073948542.png

T-16 Five-Cavity Wide-Range Crimper
(Equivalent to Delphi/Packard 12085271,
SPX Kent Moore J-38125-7)


A great shrink tube to seal those is Sumitomo's Sumitube W3B2(4X) 4/1 BLACK 4FT
I see Digikey now has it, its a 4 to 1 shrink ratio, adhesive lined, with a final recover diameter just under 1mm.
 
You need to be careful with RTV. Some use acetic acid as the curing agent (the smell gives it away) and the curing agent can cause corrosion on metal parts. There are RTVs that use different curing agents than acetic acid; but, you need to shop to find them. Permatex, Plasti Dip and Gardner Bender make something called liquid electrical tape which may be a better choice than RTV.
 
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