2ZR Turbo Yaris

[tmontague]

solid electrical work, looking good.

I personally always have used the plastic insulated terminal and only crimp (properly) and then always cover in heat shrink even if it it internal. I have never had an electrical issue due to one of my connections. The key think I think it heat shrinking it so no moisture can get in. I would never just crimp and leave as is. I have used the crazy uber expensive glue like heat shrink from CT and as much as I like it, I find that my large case of various size heat shrink I bought off ebay does a good enough job at completely sealing even though it doesn't ooze out glue. IIRC its the stuff that shrinks down 3+ times its size that has the glue. The cheaper 2:1 shrinking stuff doesn't ooze out as much nor does it become rock hard once shrunk.

Also to add to the discussion, that relay looks like the one I have currently for my dual horn set up. I have mine installed just like yours but on the other side of my engine bay and all I have done it put dielectric grease on the terminals for ease of removing them if needed. In 3 or so years my relay hasn't had an issue. It doesn't get exposed to extreme heat where it is located and it not upside down so no water can pool in it. However, a waterproof relay would be ideal.

I did have an electrical failure last year on my horns and somehow one of the smaller gauge wire had an internal failure and wouldn't send power signal to the horns from the relay. That wire sits right in front of my grill and it exposed to everything bad. I also don't think I put heat shrink on the ring terminal end at the horns. Likely water got in that way and corroded the wire. Oddly enough my multi meter would show continuity through that wire but yet it wouldn't sent power through it...