First car 89 Maxima --it's complicated
 

Hello everyone, my name is Kir,22, I'm new to this forum, this is actually my first post ever so please bare with me.
Last year I got my driving license and found the best car I could for 2k$ in my region and it was 3rd gen Maxima. This is probably a good time to mention that I'm from Ukraine, a weird Eastern Europe country. This car had only 3 owner, the last one before me had it only for a half a year so I couldn't gather much information, but it has a running wg30e motor, 5 speed manual, working cruise control and a propane fulling system. I had a bunch of problems with it, leaky fuel tank, uneven idle when using gasoline, one fuel injector didn't at all but I love this car. No one wants to work on this car because it's messy, thus most of repairs I do myself.
Last week some coolant lines cracked open and I replaced them, but in the process of removing I accidentally ripped this sensor cable (pic 1). I understand that this is some sort of coolant temperature sensor, I don't know what is its main role is. I unscrewed it and soldered a new wire to it but heated it massively in the process. What this sensor is responsible for and could I've damaged it?

Also my temperature gauge never leally worked reliably and I thought that this poorly saved wire is the one to blame, but after soldering a new peace it still doesn't work half the time.

p.s. I would love to hear your comments on the way I wrote the text






https://cimg6.ibsrv.net/gimg/maxima....60a8487a91.jpga sensor of some sort
https://cimg8.ibsrv.net/gimg/maxima....a26e9b3702.jpg
The sensor's location

*VG30E engine

Coolant temp sending unit, connects directly to the gauge cluster via a few connectors. If you're still having problems, the meter, sensor or wiring is faulty.

Buy some products to clean electronics contacts and disconnect the battery then use it on all contacts.

Our contacts are protected and kinda sealed, but after those decades, a cleaning isn't luxuous.

Thank you very much! This is a very helpful information!
To be honest I found a workaround on my own as I thought this forum is not active and now my temp gage works fine. I changed radiator cap and removed all the air/steam from the system. It seems like this sensor use coolant as a ground (that is purely my guess).

Still I highly appreciate your help!

It's active... People like me lurk