what would make my temperature gauge not function?

[t0mmy91]

i checked that both sensors are connected on the t-stat housing, the gauge doesnt even move at all. is there another wire i can check? 1999 searay 185 bowrider 4.3l alpha gen 2

 

[Lazy Daze]

Bad sender, bad wiring to the gauge, bad gauge, bad/dirty connections at gauge

 

[Bill Curtis]

Bad ground at the housing / didn't use the housing gasket with the brass grounding grommets.

 

[blaster]

The thermostat may be stuck open. Replace the thermostat.

 

[t0mmy91]

The thermostat may be stuck open. Replace the thermostat.

Hi all, There isn't a thermostat in there at the moment, I believe the previous owner removed it possibly due to overheating, I just replaced the manifolds and I will be installing the thermostat today with the metal grommet gasket. The motor did get pretty warm yesterday, I just thought even without the thermostat it would have at least came off the bottom of the gauge a little. I also read something about not using Teflon tape on the two screw in sending units on the thermostat housing, I did use that, would that also contribute to the problem?

 

[t0mmy91]

Bad sender, bad wiring to the gauge, bad gauge, bad/dirty connections at gauge

Hello, I have two sending units that screw into my thermostat housing, I'm not exactly sure what they're called, but I used Teflon tape on them, would that contribute to this issue? One is a threaded post that a wire pushes on, the other side is a plug

 

[Bill Curtis]

Yeah, never use teflon tape, as it insulates the threads from ground. I always use aviators permatex liquid and never had a problem with it interfering w/ the grounding or leaking.

 

[t0mmy91]

Yeah, never use teflon tape, as it insulates the threads from ground. I always use aviators permatex liquid and never had a problem with it interfering w/ the grounding or leaking.

ok, sounds good, i have the aviator liquid. do you put the aviator on the grounding lugs on the t-stat gasket or only around the outlet? im going to do this this morning and also remove the teflon tape. do you use aviator on the threads of the 2 screw in temp senders also?

 

[Scott215]

Make sure you properly torque the bolts for the housing. Those contacts need to touch

 

[t0mmy91]

Make sure you properly torque the bolts for the housing. Those contacts need to touch

ok sounds good, will do!

 

[Lazy Daze]

The sender (not the sensor) is the one you want to focus on (single wire).

See if the body of the sender has continuity to a ground somewhere else on the engine. That takes care of a bunch of the thoughts/advice above.

Given it's a pipe thread, you really don't even need anything on the threads.

Even with no t-stat, the needle should have come up a little bit.

 

[t0mmy91]

The sender (not the sensor) is the one you want to focus on (single wire).

See if the body of the sender has continuity to a ground somewhere else on the engine. That takes care of a bunch of the thoughts/advice above.

Given it's a pipe thread, you really don't even need anything on the threads.

Even with no t-stat, the needle should have come up a little bit.

ok, got it, thank you !

 

[Riptide III]

Did you check power at the gauge and connections

 

[t0mmy91]

yea working now, thanks. it was either t-stat housing gasket, or teflon tape on sender unit. i fixed both and now it works