I've unwrapped the harness, and I see a few things that I'm not familiar with.

One is the shielding on some wires. Seems some black wires have sections with braided shielding that's enclosed in gray casing. Some of the shielding is crimped together with another black wire, but some just hangs. I don't know if that's normal or not. What's the idea here?

Here's a pic. You can see some shielding is merged with the black wire, and some shielding is just kind of sticking out...



The other is the orange wrapping on the injector wires. I'd like to replace that as well, since I'll be peeling it and swapping in new connectors. It seems kind of different from regular electrical tape. Is it some special wrapping? What should I use?



Thanks.

 

shrink wrap would be ideal I think. then wrap the harness in tape and use new heat sheilding. the plastic stuff is cheap like 5 bucks at o rileys auto parts. comes in any color you like also. thats what I used when I fixed my harness.

 

the section with the black heat shrink tubing is just something that mazda installed because that is a connection where two wires meet and are criped together in a metal sleeve. there are a few of those on the engine harness. the injector wiring with the orange tape is also stock and nothing special. the gray wire with the shielding is important. its a shielded wire and thus must remain shielded.

 

Yeah, but my question regarding the shielding is that the braided shielding comes off some wires and is then crimped into another wire. Like you see in the picture the heatshrink has black wire with orange tacks on it going into it, AND also the braided shielding goes into it. Does the shielding itself need to be grounded or something? If so, then why are only two ends of it are grounded, and the other ones just hang loose? I think they might be the ends of the same shielding...so they're only grounded on one side?

 

When shielding a signal line against noise via either a wrapped bare wire or a braided jacket, the shielding is only grounded at one end. Grounding at both ends will introduce more noise into the signal.

 

Ok, thanks.

I guess I'll just assume everything is to spec the way it is and re-wrap it.

 

I ran into a problem. I'm testing resistance on all the wires, and couple of them that have connectors exposed to air and heat, such as TPS test connector, have massive resistance. I think corrosion is getting to the wires/connectors... Is there a way to clean the connectors, or what should I do? I believe the wires themselves are fine.

 

Actually I figured out where the problem is. It's the spot where the wires are spliced together with a crimp - I think it's contact corrosion under the crimp that would be impossible to clean without uncrimping...so I guess I'll have to uncrimp. Damn wiring is a PITA, and this is just the engine harness. Then I'll have to check the ignition harness. Luckily these problems seem to be on the wires within the engine bay, so should be easy to get to. So far I didn't find any major corrosion on interior side.

 

Ok, I guess I won't be doing that for a while, since no store that I've gone to carries crimp tools for weatherpack open barrel connectors that pretty much all cars use. WTF?

 

sometimes a paperclip works really well, sometimes a small pocket screwdriver. kinda depends on the connector.

i do have a factory mazda tool, but the screwdriver actually works better...

you need something thin and flat

 

Huh? For what? You can't crimp with a paperclip. That's silly.