Hello everyone, I have a question about adding a coolant temperature gauge to my 198*'s ** 50H. From the manufacturer the tractor is only equipped with a sweeping needle that is either in the green or in the red. I like to see numbers when it comes to these types of things instead of just colors. I added a three gauge cluster to include oil pressure, coolant temperature, and voltage. The tractor only had "idiot lights" for voltage and oil pressure. So, this little gauge cluster gives me everything I was wanting. I have already installed the new sending units and wired the cluster in. My questions are these: Are gauges calibrated to work with only a specific sending unit? Can I accurately run both the factory coolant gauge and the add-on gauge off one sending unit? Will the sharing of voltage between two gauges (both electric, analog) effect the accuracy? I'm trying to borrow someones laser to check temperatures of the coolant at the radiator, head, hoses, and such to compare numbers. The easiest place to put the sending unit for the 3-pod cluster was to remove the old sending unit and put the new one in its place. This was done because the oil pressure sending unit and coolant temp unit were in close proximity and wiring was kept simple. The added cluster gauges are simple, no warning lights or buzzers in it. Just wanted a quick turn and look at reference of the vitals. Thanks for your time.
Probably not, the sender is calibrated to the gauge. Forget the factory gauge, it's not telling you what you want to know so why have it?
He's right, sending units are calibrated to gauge and many manufacturers use several varying ohm ranges.
You could install a pipe tee fitting and use both sending units.
I've seen pipe tee extensions cause senders to give somewhat low readings. The air flow keeps the coolant in the tee cooler than the actual water temperature.
Definitely do not use a Tee. Sensors have to be in direct contact with coolant flow, a Tee would not allow any flow. You end up having a worse situation than you now have. Also if you do check out the ohms of your original unit and the new one and they happen to match, I still would not connect them in both. The voltage drop in the circuits might might give incorrect readings.
Thanks everyone for the replies. Pretty much how I figured. I'm just going to leave the factory gauge disconnected. Part of me hates having a non-working gauge, but I know I am the cause and it's **'s fault for dumbing the instrument cluster down too much.
You can use a tee fitting for the oil pressure, but the others are correct, you need the temp probe inserted in the coolant flow for it to accurately sample the temp of the coolant.