So, I should be picking up a new primary fan soon, but figured I would take a closer look under the hood while I was at it to try and find any potential issues prior to tossing a new fan in, and if the previous owner couldn't get the primary fan to turn on, I definitely found the culprit. The temp sending unit snapped off of the upper thermostat housing. Shouldn't be a big deal, I found the part number, and can pick the assembly up online for $52.66+shipping. However, there are two wires running parallel, one of which goes to the temp sending unit, and I have no idea what the other one goes to... but it looks like it's been cut. I haven't started tearing the engine bay apart yet, but I don't see the connectors that are supposed to go to the fan(s), and I'm hoping the previous owner didn't cut one of them. Either way, this is what I'm talking about:

This is what the thermostat is supposed to look like stock:


In contrast, you can see where the previous owner broke the temp sending unit in red. That, I can replace easily, but I'm really wondering what the other wire goes to (if anything), that has been cut, circled in blue:


Here's a couple more pics with the wire in question circled in blue:




^^^Anyone know what that wire is suppose to go to?

On another unrelated note, from what I can decipher based on maintenance records and the Carfax report, the original owner had the car for ~15 years, did all scheduled maintenance, and took very good care of the car. The second owner had the car for about ~4 years, and put on the mods, but the mods are all things I would have done to the car (no cheap eBay knockoff parts, seem pretty well thought-out), and also seemed like he took good care of the car. It's the owner for the last 2 years that seemed to REALLY skimp on maintenance, or at least ghetto rigged a couple small things rather than fixing them the right way (i.e. cooling system, broke a couple small things here & there, let the brakes/tires get past the point I would have let them get to ect). Which, the guy seemed like a really nice guy (a bit younger than myself), but it seems as though I'm now stuck fixing small things that should have been fixed prior to. Oh well, it's not called a "project car" for nothing haha!

Either way, if anyone knows what that wire should be going to, I would appreciate the insight, as it could be helpful in the future.

Thanks in advance!

-Brandon

I do not know what that wire goes to, but my temp sending unit looked exactly like that when I bought the car heh. My fan was on 100% of the time until I replaced it. They are super easy to break off.

I bet if you posted this on Miata.net someone would be able to tell you what that wire goes to.

erod550 wrote:I do not know what that wire goes to, but my temp sending unit looked exactly like that when I bought the car heh. My fan was on 100% of the time until I replaced it. They are super easy to break off.

I bet if you posted this on Miata.net someone would be able to tell you what that wire goes to.

Yeah, I'll probably do that, just figured I would ask locally first.

On another note, are you bringing your Miata to the install party tomorrow? If so, I'd like to take a look under the hood and see where your cooling fan connectors come from, as I didn't see any loose connectors under the hood, and am wondering if the previous owner cut them off or something to that effect...

Yep. I'm putting in my new motor mounts finally. You are welcome to poke around under the hood. I should be there around 2:30pm.

Looks like we might have a couple of V8 Miata's there as well!

Nice!! It's too bad I have to drop the Miata off at the paint shop tomorrow morning, would have liked to have compared cars side to side to figure if what else (if anything) I need to order/pick-up haha!

After my motor swap I have a wire or two that are still disconnected and I have no idea where they are supposed to go, lol. But it's been running fine for over 18,000 miles since so I'd say those wires aren't important, heh.

erod550 wrote:After my motor swap I have a wire or two that are still disconnected and I have no idea where they are supposed to go, lol. But it's been running fine for over 18,000 miles since so I'd say those wires aren't important, heh.

Haha! I contacted the previous owner, sent him a pic, and he said he had no idea, that he never touched those wires, and that they don't go to either of the radiator fans... so, it might not be important at all haha. We'll see.

I would just hate to connect a new fan, replace the temp sending unit, replace the relay ect, and still not have the thing work, so trying to be proactive

Someone over on Miata.net said he thinks it goes to the top of the power steering pump... which would make a lot of sense, as the most previous owner didn't touch the P/S (owner before him de-powered it). Would make sense to cut the wire going to the P/S pump in that situation, and would explain why the most-previous owner had not touched that wire which was obviously cut deliberately. Now I just need to cut the fan connectors haha!

Yep. Top of the power steering pump. Hope that helps!

94mx5 wrote:Yep. Top of the power steering pump. Hope that helps!

Thanks for the confirmation, and thanks again for the fans!

I'll be bringing my Haynes manual also so you can check out the wiring diagrams in it if you want.