Temp sender replacement

[CampulanceMan]

So I installed a turbo (Hypermax) on my '93 7.3 IDI and that's working pretty well (need to adjust it a little because I'm only getting up to 7 psi of boost, but for now that's ok) but since I installed it I've always had the Engine Temp light turned on on my dash. I didn't think much about it because I have an aftermarket coolant gauge that works well. I had to take the truck in for some work recently though, and the mechanics pointed out that somewhere along the line of installing the turbo I pinched a coolant sensor wire which caused it to not read correctly and led to the glow plugs heating continuously. I guess they un-pinched the wire and also replaced one sensor (Duralast SU201) but told me there's one more sensor I need to replace to fix this issue, but they were out of stock at the time and I was driving across the country. The Engine Temp light is still on so I've decided to get around to replace the second sensor, but I'm not sure which one they were talking about. Would it be this one maybe Ford E8TZ-9E939-A?

 

[IDIBRONCO]

I'm not sure that I'd take your truck back to that shop. If the glow plugs were on constantly, they would burn out and your truck wouldn't start. If you haven't had any starting issues, I feel that you got ripped off on this one. I don't know what other work was done to your truck or how it panned out afterward, but the glow plug/coolant sensor wire thing sounds way too fishy to me. As far as I know, there is no coolant temp sensor that affects the glow plugs on your truck. The glow plug controller works off of the resistance in your glow plugs. The hotter they are, the longer the controller keeps them "on".

 

[Garbage_Mechan]

Correct. No connection between glow plug controller and temp gauge or temp light.
For the temp light I suspect a grounded wire. The light sender is the bigger one on the left head. If you unplug it and light is still on then you have a short to ground on the wire. Follow it back and find it.