spekdah

in the instructions it says use '18-gage twin conductor wire' for the sender, my gauge is electrical, Well nuttin came with the gauge so can anyone tell me what kind of wire this is ( stereo wire??) cos I got a heap of wire lyin around and I might have some.
What else in my bay has the same gauge wire so I can compare?






"cheap bastard" I hear you think

Mahjik

iTrader: (1)

Actually, 18-gauge will get burned up under the hood with the temps our cars usually see (unless you wrap it with something). I'd recommend at least 14-gauge wire so you don't have to go back and rewire it again (like I did).

DaveW

The gage of the wire has almost nothing to do with its temperature capability. That is almost entirely dependent on the insulation. Most of the 18-gage speaker wire insulation is made for cool temperatures under 90C. Automotive wiring insulation is made for higher temperatures (I don't remember the exact rating) seen in engine compartments, regardless of the gage.

Anything heavier than 18-gage is overkill for gauge wiring, and its additional stiffness can cause problems.

broken93

http://www.painlesswiring.com/wireterm.htm

Any of the 18 gauge stuff will work. It's designed for underhood applications.

Instead of buying molded 2-pair wire (like speaker wire), a trick I learned working with stereo equipment: cut the wire twice the length of the intended run. Fold it back on itself, and put the fold (U) in a drill chuck. Spin the drill while you (or someone else) holds the other ends of the wire in tension, and you'll have a nice tightly wound twisted pair to use.

Mahjik

iTrader: (1)

Well Dave,

I used "Automotive 18-gauge" wire and it failed halfway through my second session at the track. I rewired it with the same and it lasted about 1 month of street driving before it failed again. The last time, I used 14-gauge and never had a problem again (I'm not the only one I know who had this problem).

So, from my experience, I would still suggest 14-gauge unless it's going to be wrapped with something.

DaveW

Mahjik,

That's very interesting. Where was the wiring that failed, and how did it fail? Did it melt the insulation, or did it fatigue off at a connection, or what? I'd like to understand the root cause of the failure so that I and others would be able to avoid similar problems.

If the wire failed from fatigue, that could be a mounting or strain-relief issue.

I've used many gages of wiring on my Formula Continental racecar, and have never had a wiring failure, at least partially due to care in eliminating fatigue points and wire vibration.

There are various grade of insulation, including Teflon, which can stand extremely-high temperatures.

Mahjik

iTrader: (1)

Yep, I know about the other types of insulation. However, the normal "Automotive" wiring most people will find locally won't be anywhere near the higher end stuff you can order online. Actually, the 14-gauge I ended up using which has worked fine was from Home Depot.

I never found or looked for exactly where in the wire the connectivitity stopped. I just know from testing that I wasn't getting a signal all the way through the wire (using my voltmeter). I wasn't too concerned with disecting the wire to find the exact failure (since I just needed it to work). I noted that the wire failed somewhere between the fender area (driver's side where it's routed into the cockpit) and the actual sender, but that's about it. That leaves quite a bit of wire where it could have failed.

Granted, running the car on the track is going to generate a lot more heat than street driving.

DaveW

OK, Mahjik, you win!

I can't argue with something that works!

Mahjik

iTrader: (1)

Naw, nothing to win, only a good discussion.

I just recommend the larger wire since most people will do like me: find some wire locally. Most local places have cheap stuff that doesn't seem to be up to the task. It's hard to place an online order for just "wire" so I can understand.

IMO, as long as the 18-gauge is either wrapped or has higher quality insulation than the cheap stuff, it should be fine. However, "speaker wire" most likely isn't a good candidate.