What kind of connectors for gauges

[scooper]

Hi, I am wiring up some spa dual gauges in my car. Should I use tap in squeeze connectors, M-F slide connectors, or solder and heat shrink for the wiring in the car? I will probably solder the wires together in the engine bay. I threaded a dozen wires thru the passenger firewall and plan to splice the gauge wiring harnesses (cutting them in half) to them.

I don't think I ll be changing gauges regularly but having the option to disconnect wiring when fixing stuff can be a plus. Thanks for any comments.

[TXBDan]

Crimp bullet connectors are fine. It's nice to be able to remove them if/when needed.

[JBasham]

For gauges I actually like to use long-ish leads and some kind of simple, removable connector like a bullet or blade. That's just for convenience when I need to pull the panel for maintenance.

I don't like the tap-in connectors because I had one fail on me due to vibration. I like to cut the B+ or the ground wire and connect in a new pigtail lead for whatever I'm adding. I

t's not a big deal with gauges, but I also try to remember how much current draw I'm adding to the circuit so I'm sure I don't exceed the fuse or breaker rating. If it's even close, I will pull a new B+ line from the main feed, with a breaker or fuse.

Solder connections tend to have vibration failure issues, so they need to be heat-shrinked not taped. And they can wick moisture up into the insulation if not heat-shrinked well. I use them when I'm building up components, but not for auto, just because I find crimps easier and faster.

Crimped connections are fine, but they will fail on me if I don't use a connector that matches the gauge of the wire. Or if I try to improvise a crimping tool, instead of using the specific kind of crimper designed for that connector. The best connector bits for me seem to be the marine-grade hardware with the integrated heavy-duty heat shrink. It's not that expensive to get an assortment box off Amazon and it will last me a couple motor-swap and gauge panel builds.

[scooper]

Thanks Dan and Jamey! I might take a close look at the bullet type connectors. I bought some blade type connectors and had some tap in connectors already.

[jimmypet]

I don't want to be that guy, but I guess I will...
First take any and all of these things (if this is what you mean by squeeze connector):



And throw them in the trash or give them to someone who you do not like.

I like simple non insulated spades on gauges with heat shrink for easy removal of gauge panels.



I hate seeing Walmart / Kmart / Autozone style insulated connectors on race cars.
They belong with the Scotchlok connectors, in the trash or maybe for when you are fixing your lawnmower.

Although different connector (eyelet vs spade) this pic is sorta what you are looking for (or at least the mininum I will put on my race cars).

[E36forever]

When I did all of my gauges I soldered except for the grounds which I screwed down. You run the risk of a bad connection with ANY connector otherwise.

I never intended to change or remove the setup.

[TXBDan]

When I did all of my gauges I soldered except for the grounds which I screwed down. You run the risk of a bad connection with ANY connector otherwise.

I never intended to change or remove the setup.

Not really. Solder splices are fine, but can be more prone to fatiguing where the solder stops if not well supported. They're normally only used when space is tight. Crimps are preferable for high vibe situations and are the standard for aerospace harnessing. Not surprisingly, the key for both is using proper parts with proper tooling with proper inspection.

(I'm way too familiar with NASA-STD-8739.4)

[jimmypet]

Not really. Solder splices are fine, but can be more prone to fatiguing where the solder stops if not well supported. They're normally only used when space is tight. Crimps are preferable for high vibe situations and are the standard for aerospace harnessing. Not surprisingly, the key for both is using proper parts with proper tooling with proper inspection.

(I'm way too familiar with NASA-STD-8739.4)

^^^^^ All of this ^^^^^

[scooper]

When soldering what is the preferred technique? twist in helix, two loops, or just lay wires side by side for ease of removal later? Thanks again guys!

[JBasham]

Never side by side. Solder won't make a physical joint worth relying on.

[TXBDan]

side-by-side is actually Ok. It's fiddly though. The lineman method of physically wrapping the two wires together is handy since it holds your work together before soldering.

https://prod.nais.nasa.gov/eps/eps_d...ER-002-006.pdf

Start reading at page 80. It's actually a pretty handy guide and oddly enough, not rocket science.

[scooper]

Thanks! Another question: why are the insulated connectors made of hard plastic? Doesn't this make it hard to crimp? special crimp tool needed?

I may go return the ones I bought and get the non-insulated ones then finish with heat shrink as jimmy p. suggested...Thanks again guys... gauges and wiring are in. Just need to finish connecting the wires.

[JBasham]

Edgar, I have no luck making good long-lasting crimped connections with anything other than the proper crimping tool for that kind of connector. For the crimp-on spades and eyelets, etc like Jimmypet so excellently pictured, the crimper is not an expensive tool. Squeeze that sucker shut like you're trying to break it.

It mashes right through the plastic collars. Or you can pull the plastic off the metal connector and throw it away.

[scooper]

Thanks Jamey! I bought some bullet styled ones and will remove plastic insulation. Then I'll heat shrink them. I'll squeeze those suckers thanks! hahaha