View Full Version : Temp gauge not working - 94 PS205
06-11-2014, 09:04 AM
My new to me 1994 PS205's temp gauge is not working. I really have no idea where to even start. Any suggestions on how to find and correct the issue the issue?
Appreciate any help you guys could offer.
06-11-2014, 10:46 AM
Check your sending unit. They fail more often than gauges.
06-11-2014, 11:37 AM
With the key in the run position find the sender and disconnect the signal wire from it. Your gauge should go to zero (Or 80 or whatever the lowest value is) if it wasn't already there. Contact that sender wire to ground and your gauge should go to 250 (Or whatever the max is).
If the above checks out then your sender is bad. If your gauge doesn't move when the signal wire is grounded you've either got a wiring or a gauge issue.
Check continuity on the signal wire from the sender to the gauge by grounding one and and testing resistance to ground on the other end. It should be near 0 ohms.
Check that the gauge is receiving power and ground on the appropriate wires. There should be 4 wires to the gauge. Signal (From the sender), ignition switched power, ground, and Nav light switched power (For the backlight).
06-12-2014, 09:35 AM
I just went through the same thing. First, the gauge was reading lower than normal. Next, the sender shorted out.
First do what Jeff d mentioned above.
Get a hold of a 100ohm resistor and ground the sending unit wire through this and it gauge should read 170.
You can also test your sender:
Here is the replacement gauge I bought:
06-12-2014, 06:35 PM
Thanks everyone. The weather has been nasty the past couple days so I haven't had a chance to get out an work on it yet but I appreciate the help.
07-12-2014, 09:15 PM
Thanks guys, turns out the previous owner removed the thermostat ... Put in a new one and temp gauge is working great now.