On cold TX mornings, (few and far between) I let my truck warm up for approx 15 min before heading to work. I've noticed that my tach drops to 0 when I take my foot off the accelerator and picks back up as soon as I touch it again. The same thing happens when I use cruise control (turn cruise off and needle drops to zero, turn cruise on and tach reads normally). Performance doesn't change, no check lights come on, no codes found when I use scanner. This issue goes away about 5 miles into my commute.

I decided today was a good day to investigate the issue. My first instinct was it had to be a loose wire or bad connection somewhere in the tach circuit. I needed to replace a dash light and figured I would start on the interior before rolling around under the hood.

Upon opening up the dash, I discovered the previous owner installed a remote-start alarm system. I'm in the process of removing all the #%! tap splices from the OEM harness, soldering broken strands, and coating the bare wires with liquid tape...Which brings me to the reason for the name of this post.

My experience, with tap splices, has always been negative. No matter how ''professionally trained'' alarm, trailer hitch, and stereo installers claim to be, 90% of them rely on the tap splice when installing aftermarket equipment. Sure, everything works good for the first year or so. However, it's only a matter of time before the gremlins find the breached insulation and leave us scratching our heads.

When I turned wrenches for Freightliner, electrical diagnostics paid "time on the job" Our service manager's policy was .25 hours additional for each tap splice we cut out of the factory harness. I ate steak several times because some chrome shop installed 100 chicken lights down the side of a 53' reefer by either tap splicing or just stripping and twisting the wires together.

Do yourself a favor by purchasing a soldering iron and a good wire terminal kit. Taking the extra 15 minutes doing it right the first time will leave you hours to do more important things...like drinking beer. Apologies for the long winded rant.

 

Absolutely no apologies are necessary when preaching the gospel of "Do It Right The First Time" around here at FTE !

I take issue with absolutely NOTHING you wrote, and I'm real picky when evaluating electrical advice.

Good job, and reps sent!

Pop

 

Thanks, Pop. "Do it right the first time" is what I've instilled in my 17yr old daughter while working on her 1970 C-10. We spent quite a few long nights cleaning up under the dash and hood. The body might be rough, but the lines and wires are purdee. She doesn't know it yet, but she'll be helping me put my truck back together tomorrow morning so I can get to work and make $$$ to buy her a bedazzled welding helmet. (She keeps setting mine down in the dirt)

 

Right now I have none on my truck but who hasn't hooked up a trailer and finding some light not working then chasing it down to those crappy plastic tap splices. You are 100% correct in they last a year or so and then cause more problems then they are worth. I too have almot 34 years as an electronic tech and was never allowed to use these. I have about 10 different soldering irons in my garage.

Dale

 

Something to remember:

In reality, the concept behind these kinds of splices is relatively sound.

They were developed by ATT (The Bell System), back in the days when they were THE phone company, to make reliable wire connections.

They are called Insulation Displacement Connectors (IDCs), and can be reliable if used properly. They hardly ever are, however, and THAT's
what gives them such a bad reputation.

There are a lot of size-selection, environmental, and assembly techniques that all must come together properly for them to perform as they
are designed to do. Using one for 16-guage wires on 18-guage wires will only get you into trouble. The reverse is also true. Some are for
soiid wire only, some for stranded. Some are acceptable for use in vibration, some not. With so many variables, it's no wonder they so often
fail.

However, remember that computer ribbon cables are terminated by IDCs, and are used in the computer you're reading this on, and they are
reliable, very reliable. But they also aren't installed by some ham-fisted U-Haul goon, or the kid at the local stereo shop who was shown
once how to use them by someone who was equally unqualified.

So far as I know, there are none in use on my truck, and I don't plan to be the one to start. I like 63/37 solder and shrink-sleeving.

Pop

 

Ditto,

Steve

 

Exception to the rule! While agreeing with everybody on everything here, there is a connector worthy of this task and environment: The filled Scotchlok IDC [LINK] [BIGGER]. I use a larger version of these on all my trailers (including the boat trailer) and on the truck. I've used every size 3M makes, and I've used them for anything you can do with wires that fit in these. I've even spliced cut Ethernet cable with these (in a pinch) and they work. In ten years of using these, I learned one rule with their use: Do it right, inspect it, and it works. I've lost count of how many thousands of these I've used. In 10 years, the only problem I've ever had with this connector is when it was incorrectly crimped and not caught in inspection during installation.

 

I agree and do not believe every connection needs to be soldered. I think the OP was referring the quick connects the RV industry and others use in mass. A sure recipe for trouble down the road.

I had to troubleshoot an inoperative ceiling light in which the manufacturer spliced together short sections of wire using quick connects. 12 quick connects feeding one circuit!

Steve

Steve

 

Back in my days as a professional tech and as a tool man, we refered to the Scotchloc as a "come back clip" because the job always came back to be redone.

Barney

 

As long as you customer never figured out what was going on, it is a great way to generate repeat business, lol!

Steve

 

I do not like to cut wires and am not talented enough to solder so i do use them.
As mentioned though, they are not one size fits all. They must be matched to the wire size.

(On a side note, are you guys having to scroll back and forth to read this?)(Try editing to keep it on the left side.)

 

Another side-note:

What would also apply is to appropriately re-size photos, but it seems most people haven't any idea how to do that.

A good rule of thumb is to not have the photo any wider than about 600 pixels. That's enough for good definition, and will not likely
be wider than anyone's screen.

But it's not my place to be the Posting Police, so it's just a suggestion....

Pop

 

Many years ago, one of my electronics instructors instilled in me the concept that the primary advantage of soldering is not physical strength, but rather the prevention of oxidation. Years of personal experience have reinforced this in my mind.

I believe that is also the reason for the success Tugly describes with the filled connectors. I think tap connectors could be OK if they are properly sealed afterward with tape or RTV. Sometimes I even use hot melt. Oxidation is the enemy, and the automotive environment is a very harsh one.

 

I bought my enclosed trailer for $400 it's only 5 years old not in too bad of shape.

When I got it the brakes were not in working order on all but 1 wheel.

I jacked up each side and found the manufacturer had used splice connectors to connect the brake wires.

About an hour and some solder later all wheels came to stop with a nice "Thud" when spun in the air and the trailer brakes applied. I'm sure it's only a matter of time before I have to go back and redo that last wheel but it was cold the day I did the others so I wasn't looking for extra work.

 

I have a 1976 Motorhome that I have been working on since I was a teenager. And here this last summer I started to rewire parts of it due to the fact that what was done 35 yrs ago was wrong or poorly done. I look at some of the things I had done and say to myself what the heck was I thinking. Well I was a punk kid "I wasn't thinking!" I am only about half way done with the rewiring.
By the way I have clue on how to resize my text to fit the page. SORRY!!
I'm old and not too bright when it comes to computers. But I can rub 2 sticks together and make a fire.