88' Zinno M3 (Progress Thread)

[bradnic]

You don't want bare metal exposed to air, moisture, contaminants.
You don't want a mechanical connection or splice to "bounce" around from vibration.

The adhesive on electrical tape gives, slips. It leaves a nasty residue too. It's not permanent. The automotive grade harness tape does not do this. There's two kinds on E30 era BMWs, one for the interior which is softer, and a thinner tape used for under hood / heat sensitive areas. afaik they're still using the same tape.

What I do, without fail:

1) I always solder. Mechanically attach the wires together before soldering. Heat the wire and let the wire melt the solder. Use pliers or small clamps around the solder area to absorb the heat and protect the insulation during soldering.

2) I always put heat shrink over the solder joint after it's cooled down. It seals the joint and holds it together

3) I then cloth tape the heat shrinked connection.

4) I make sure the harness is properly attached to the surrounding area. all those stupid little broken plastic clips around your car? I replace the darn things.

[jhaurimn]

Didn't think this discussion would develop, but its all good info to know.

I agree, I should of used heat shrink tubing, but just didnt have any at the time and didnt feel like making a 3rd trip to autozone that night :) but I will definitely replace the tape with heat shrink tubing the next time Im in there. I taped into the side marker lights, btw.

You say automotive grade wiring tape. So Tesa harness tape would work perfect? I have some of that, but I felt like electrical tape would seal better. doh

So with everything you've done to this car, "I don't have the skills" is your fallback? You can do better than that.

Lol! Well I appreciate what you are saying. Thank you for keeping me in check :)

[bradnic]

The copper had basically corroded out from the solder splice.

That repair was poorly done. Look at the corrosion on the wires, especially on the right. That's not from soldering.

[bradnic]

Solder wicks into the strands of a wire and makes it brittle, susceptible to cracking from fatigue related to vibration. This is a well-documented phenomenon.

Also true, but again it's not the soldering that's the issue. It's how you mechanically seal and support the solder connection afterwards.

[bradnic]

I agree that how you seal the insulation could be a problem.

Electrical tape is a BAD idea on auto wiring, especially anything external. Not the soldering itself though. You could certainly argue that a butt splice or crimp is much more susceptible to corrosion because the amount of mechanical contact between the wires is limited compared to a properly soldered connection.

Use heat shrink tubing and auto grade wiring tape.

GREAT pics btw!

[The Dark Side of Will]

That is complete BS. What are you basing this on? You can argue that a circuit board solder pad could separate from mechanical vibration. But not a soldered wire.

Solder wicks into the strands of a wire and makes it brittle, susceptible to cracking from fatigue related to vibration. This is a well-documented phenomenon, part of the reason why OEM's just don't use solder on their harnesses and why soldering for aviation and aerospace applications is very very tightly controlled.

[The Dark Side of Will]

Here's what solder and electrical tape looks like in a couple of years:


The copper had basically corroded out from the solder splice.


I replaced with this:


Uninsulated butt crimp splices and shrink tube (not yet shrunk in the photo)... much neater, much longer lasting, much more professional and no chance of burning myself with solder.

[bradnic]

Solder on a car is generally bad news because of the vibration.

That is complete BS. What are you basing this on? You can argue that a circuit board solder pad could separate from mechanical vibration. But not a soldered wire.

[The Dark Side of Will]

Dude, they are splices. Soldering wires together will involve more cutting, and is overkill. Not to mention going back to stock is harder that way.

:loco:

Solder on a car is generally bad news because of the vibration.
Were these lights not installed in any cars at the factory, or just not wired that way from the factory?

Assuming they were tapped into the headlight wires, you could pull the pins on the headlight wires at either end, cut the old pins off and crimp on new pins with both wires in them. That way you end up with sealed connectors and the wiring looks stock.

Which is why I wrapped them in electrical tape ;)

Also worth mentioning, I do not have a soldering iron, nor the skills to solder.

So with everything you've done to this car, "I don't have the skills" is your fallback? You can do better than that. ;)

[jhaurimn]

t-splices allow for a lot of moisture to enter the splice, and over time corrode the wire, which could eventually break. These splices as well often cut through some of the wire, causing them to fail prematurely. With that all said, I to have used them for things, for the reason, "well I may go back to stock," or because its less work than solder.

Which is why I wrapped them in electrical tape ;)

Also worth mentioning, I do not have a soldering iron, nor the skills to solder.

[rcsoundn1]

t-splices allow for a lot of moisture to enter the splice, and over time corrode the wire, which could eventually break. These splices as well often cut through some of the wire, causing them to fail prematurely. With that all said, I to have used them for things, for the reason, "well I may go back to stock," or because its less work than solder.

[jhaurimn]

Don't do a nice job on the rest of the car and then cheap out on wiring...

Dude, they are splices. Soldering wires together will involve more cutting, and is overkill. Not to mention going back to stock is harder that way.

:loco:

[The Dark Side of Will]

t splices

Don't do a nice job on the rest of the car and then cheap out on wiring...

[jhaurimn]

Not much of an update, but it seems like I was able to fix the foggy high beam. Ive been messing around with ways to pour windex into the lense and getting it out without fogging up again. Seems like I got it to stay clear, at least for now. I also took apart the projectors for the low beams and cleaned them up. That alone increased light output significantly.


And I wasnt able to wire the city lights initially because of some crappy quick splices not working. So I got some t splices, and got them working.

[SteadyAim.]

Car looks awesome! So minty fresh compared to mine :(