88' Zinno M3 (Progress Thread)

[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!

[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]

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.

[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]

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.

[The Dark Side of Will]

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.

For brittle fracture due to fatigue, support, basically to the point that the joint doesn't see any vibration, is more important than sealing.

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

Obviously solder doesn't corrode wires. The goofball who did that wrapped questionably soldered joints (an end splice rather than a butt splice) with electrical tape... my point was that electrical tape hardly guarantees a good seal on an irregularly shaped joint (like a T-splice).

However, OEM's use lots of electrical tape to protect long harness trunks from the elements because on a regular shape like that, it can be wrapped to seal well.

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

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

You're welcome ;)

There's a HUGE amount of info on the internet about how to do automotive wiring the "right way"... this thread is a great source of info:

http://www.corner-carvers.com/forums/showthread.php?t=34419

[jhaurimn]

I appreciate all the info guys! Learn something new everyday! And I still have plenty to learn on electrical stuff if you cant tell :)

[bradnic]

fwiw we're definitely in agreement Will.

[rzerob]

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

I use the marine type heat shrink with the adhesive inside. That seals it where I feel it doesn't always need taped over top.

[bradnic]

I use the marine type heat shrink with the adhesive inside. That seals it where I feel it doesn't always need taped over top.

I think BMW agrees with you. Just did a full rear suspension resto on my 318is. This is a very nasty, harsh area of the car for wiring. The diff speed sensor wiring came much the way you described. BMW uses a thick vinyl tubing and just the insulated wires within it - no tape.

[The Dark Side of Will]

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.

I do the same except I don't solder. OE style connector pins are never soldered from the factory, but they are well sealed and still last decades if they're not mistreated.

I try to arrange my wiring so I don't have to splice, and instead replace pins in connector bodies.

When i do have to splice, I just use uninsulated butt crimp splices and shrink tube. Sometimes I use a short piece of the next smaller size shrink tube (big enough to fit over the wire, but too small to go over the splice) at either end of the splice, then the size big enough for the splice on top of everything.

The shrink tube acts like its own strain relief to prevent wire breakage from fatigue. I haven't played much with the adhesive lined shrink tube... I've been thinking about getting some samples to try.

[bradnic]

Rock solid. Don't disagree with your comments or approach at all. I try never to cut connectors, and use the right pins bushings and housings when repairing the ends of cables.

For wire repairs though I solder. Seems to be the only difference in our approach.

[The Dark Side of Will]

Rock solid. Don't disagree with your comments or approach at all. I try never to cut connectors, and use the right pins bushings and housings when repairing the ends of cables.

For wire repairs though I solder. Seems to be the only difference in our approach.

We'll just respectfully disagree about the necessity for solder then. ;)

I use the marine type heat shrink with the adhesive inside. That seals it where I feel it doesn't always need taped over top.

What product do you use for adhesive lined shrink tube?
Is it more like a hot glue that melts when you shrink the tube or is it gooey to begin with?

[rzerob]

What product do you use for adhesive lined shrink tube?
Is it more like a hot glue that melts when you shrink the tube or is it gooey to begin with?

I have used multiple brands of the marine heat shrink. Marine as in boat. It looks like a regular heat shrink tube but a little thicker. I am assuming that the adhesive is coated on the inside. When you apply the heat the tube shrinks and the adhesive melts and forms a water proof seal. It is all I use anymore.

Sorry that we jacked your thread OP.

[motors4me]

I replaced the missing wheel choke. However the wingnut I bought for it doesn't seem to fit. What part is supposed to hold it down? (Also, yes it bugs the hell out of me that it's too cold to clean areas like this :( )

Did you figure out what holds the wheel chock down?