Temp Gauge Bouncing Around

Hi everyone,

I am brand new to boating and this forum. I used the forum extensively to help me with my decision to buy a boat and what boat to buy. I noticed all the Knowledgeable people on these forums and thought it would be great if I could get and hopefully one day give some advise.

I recently purchased a 2005 Glastron SX 175 with a Volvo Penta 3.0L.

I had the boat out on the water for the first time this weekend. I had one issue with the engine temp gauge. It bounced around between 175 and 250 (max) for a while after initial startup. It was literally swinging back and forth quickly. I thought I may just have a bad gauge or sending unit / sensor until after a few minutes it pinned itself all the way at 250. At this time I turned off the motor and checked the cooling system. The hose (narrow) that pulls water into the engine was cool and the hose right next to it (larger) was warm. I could feel fluid inside each of these hoses, so I assumed water was flowing through the cooling system. I am new to boat motors so I am assuming I was checking the correct hoses. I fired up the engine and ran it for a while and the temp gauge just started to work correctly after about 10 minutes.

Does anyone have insight or advise for me on this issue?

Thanks!

Re: Temp Gauge Bouncing Around

Bad ground at the sender or gauge. You can spring for an infrared temperature gun (auto store and other places) and check the temperature directly at the thermostat housing or such.

See if you can get to the back of the gauge and remove/clean the terminals. Frankly giving them a wiggle where they attach might be enough if they are spade connectors.

Re: Temp Gauge Bouncing Around

I will give it a try and post the results in the next few weeks. I don't think I will get the boat out on the water again for a couple weeks.

Thanks!

Re: Temp Gauge Bouncing Around

The ground wire on the back of the gauge was loose.

Thanks again for your help!