What Really Is The Best Way To Connect Or Splice Automotive Wiring?! WITH PROOF!

Automotive wiring repair is and probably always will be a hot topic of debate. In this class we objectively look at each of the "common" wiring repair methods and compare them thoroughly. Enjoy!

Tools Used:

[GearheadSchool]

Seems like everybody had a different opinion on wire repairs. Thanks for providing some hard data on this. I have been in automotive education for over 20 years and never saw this topic covered at this level. Using thermal imaging on a live connection took it over the top!

[bradbeck]

Non-insulated butt connector paired with dual wall hot melt adhesive lined heat shrink tubing and make sure to heat untill the glue oozes out both ends. Best connection you can get IMO. The non insulated butt connectors (the ones that are just a bare metal barrel) allow you to use the more aggressive crimp notch, keep your connection small and discreet, and IMO is more professional looking. Also, I like being able to use longer sections of heat shrink than is provided with crimp n' shrink connectors when I deem necessary or appropriate in more exposed areas. For reference I work on class 8 dump trucks, tractor-trailers, and earth moving equipment in salt ridden PA.

[mikecont]

Your videos are so informative. The best step by step videos out there. Always learn so much.Thanks for taking the time.

[andrewwilson]

Adhesive lined heat shrink is a great way to up your splices to the next level. It helps restore mechanical strength to the joint.

[SmittySmithsonite]

Ahh, no fire! Maybe next time. 🔥 😁

Reminds me of when I was 16, and used those unsealed connectors under the hood of my fairly new '88 S15 pickup. I hooked it to the battery first, with no fuse, of course, as I fed it through the door between the hinges. 🤣 As I yanked on the wire to get it through the fender, under the weatherstrip and into the cab, it suddenly went from ambient temperature to about 200°F in a blink!! Lucky for my skin, it was only a very brief short to ground. I learned a lot about 12v electrical that day, especially after I fed power to the speaker wires of my equalizer, and watched the smoke come out of the unit. Released the magic pixies for the first time! 😂 Ahh the good ol' days! 🤣 Oh, and all those connections gave me nothing but trouble after the first rain storm.

This was a great presentation, Mike - really enjoyed this one. 👍👍

[JasonTheMunicipalMechanic]

Watch out for cheap amazon crimp and heat shrink but connectors. I got a bunch that were really thin and when crimped the wire would just pull out. I’ve used them for years and I never had that problem until I got the ones I had the problem with.

[LTVoyager]

It is better if you don’t solder so far toward the ends of the coils. Just solder 3/8 to 1/2” in the center. This will give you all the strength and conductivity you need, but greatly lessen the chance of a failure due to vibration of the wire stiffened by solder. The last couple of coils provide a smoother transition from stiff soldered section to flexible copper wire and greatly increase resistance to bending/vibration failure. The shrink tubing will contain the unsoldered coils more than adequately.

[codysautodiagnosticsprogra]

Great stuff bud, thanks for the demonstration. I’ve always wondered what connection was best

[bgregg]

I've always used solder & liquid electrical tape but I may need to try those heat shrink butt connectors now.

[jmccoy]

I think what really matters is the joints resistance to vibrations and the elements.... would like to see a test against vibrations and the elements and measure the resistance value across the connection

[GoTechTraining]

Skip to 11:30 for the start of video! Thanks for watching. Please share your thoughts below :) ~Mike

[alexandergonzalez]

Hoping you can give some direction on my recent discovery; Car does not crank in park; it cranks in neutral, no start. Pulled stater relay the load side is hot all the time without key on; control side reads 3.44 volts with key on however it reads 12.39 volts with key in start. what is pulling down voltage on the control side?

I use the test to positive touching the ground side of control, it lit up, why? If ground side lights up is there unwanted resistance bad ground? Its not suppose to light up if their is a good ground right or wrong?

The neutral safety switch works fine, it was tested at the starter relay with test light on control side it does not light up however with a volt meter on control side, key on, it reads 3.44v; key in start position the meter reads 12.39v. When I shift to reverse the test light turns off, when I shift to neutral, it turns back on, that is how I verified safety switch works ok.


What should do next? what is pulling control side to 3.44v? Is it suppose to be 5 v ref?
Respectfully,
AG

[wyattoneable]

Outstanding information and very well presented Mike. Nice to have met you.

[iantoniou]

Hi, you are doing excellent job. Could you make a video about repairing CAN cables? I think that there are some special specs (low resistance etc) and specific procedures about CAN repair or i am wrong? Thanks man!

[khasem]

Very informative and well represented
Thanks for the hard work

[gorillahumpr]

Of course force isn't applied to wires. Its more about vibration basically from what I've been told. A friend of mine who does wiring for a racing team said to never solder. He says it creates a fine point at which the solder stops and the wire bends which creates a point of failure. Thats racing of course and regular cars are mush compared

[LTVoyager]

Need an electric heater for a load. That work great and many have two or more heat settings so you can vary the load.

[marktirabassi]

Hi and thanks for the advise how to join wires, but I’ve noticed the wires there using to my maf sensor are not stranded but super tiny wires . I don’t think any of these methods will work with them

[Jpilgrim]

I imagine those crimpless connectors use crappy lead free solder. If you could get some with some quality 60/40 rosin core leaded solder then they’d probably give much better results. Crimp and seal butt connectors or soldered with marine grade heat shrink with adhesive is all I use and fits every scenario you’ll ever run across.

[alexandergonzalez]

Glad you enjoyed some vacation time balancing work with recreation is important. Toyota corolla 2000 is a no crank in park;crank in neutral; no start. Did voltage drop test interesting, what I found, there is a thief on the ground side. Positive battery to positive starter battery cable voltage drop is 0.50 volts with key on position using a remote switch from engine bay; Negative battery to negative solenoid trigger wire is 8.70 volts on ground side high resistance where?. Why I got a half volt drop on positive side don't understand. Will be moving on to the engine block for another voltage drop test on ground side battery. What baffle me is on starter relay the control side has a 3.44 low volt reading so low it could light test light. Use meter 3.44 v key ON; key start 12.39 v so my neutral safety switch is good yet it did not start in park. Appreciate any insight you may have and can I get power distribution wire diagrams for the corolla 2000 from your website?
Respectfully,
AG