Ever since I got this bus the water temp gauge in the dash (electrical MCI) has not been accurate. After learning that the overheating shutdown and engine bay gauge (mechanical) worked properly, I let it be for a while.
It's time to fix it. It's the only gauge in my dash that doesn't work properly. It appears to read about 30 degs lower than the engine water temp gauge.
I cleaned the connectors and when I grounded the sending unit, the needle on the dash gauge shot right over to the right. This made me think that the sending unit needed replacement. I got the number off the unit (334R by Stewart Warner) and replaced it. Now it pretty much reads the same as before maybe a few degrees higher.
Before I start my testing for bad connections and old wire, is 334R the correct water temp gauge for this MCI gauge?
(https://uploads.tapatalk-cdn.com/20180327/ecad5ea15d0a4d554b2ec4949d0fa6e7.jpg)(https://uploads.tapatalk-cdn.com/20180327/54485dc1a062e4cb2e44e7c17b765378.jpg)
Id start by cutting off that terminal and install a new one with good wire crimp. A little corrosion or poor connection can effect gage accuracy. I dont care for your dash gage btw, Too little needle movement between hot and too hot.
New terminal done.
I agree that the gauge is not ideal. I might have to look for one with the full sweep. (https://uploads.tapatalk-cdn.com/20180327/4e02bb6e1a3bbd160835fd08ca8970be.jpg)
I replaced my engine temperature gauge with a Speedhut. The old Teleflex gauge was only a quarter-sweep. and it was impossible to really know what the exact temperature was. The Speedhut is a full-sweep (270 degrees sweep) with a stepper motor, so its resolution is three times better, and it's probably much more accurate as well. Speedhut will make them to order with your choice of font and colors, then they will match whatever else you already have. I also got a Speedhut oil pressure gauge and transmission temperature gauge, so now all my critical gauges are trustworthy. Well worth it.
John