My temperature gauge is no longer working, so I suspect it is the coolant temperature sensor. But I see two on my Jeep. One is in the thermostat housing, and one looks like it is located on the intake manifold near the firewall on the driver's side. I do not have an electric cooling fan on this Jeep - looked like it never came with one, this is a Jeep that was also sold with no A/C. Which sensor do I need to replace to get the gauge working? Thanks in advance.