1989 Mercruiser 350. Temp sender and gauge

[Greg68S]

I have a 1989 Thompson Carrera with a merc 350 alpha one gen one. I replaced all my gauges with new white Teleflex gauges. They look great and all work perfectly except fir the temp gauge. The old one worked great but was fogged over as most my gauges were. I replaced my temp sender with the correct one per merc. But the gauge still doesn't work. All I can find out so far is something about "sender code D required". Any input? Do I have the wrong gauge? My old one was marked with an L and and H (Low Hot) the new one is marked 100 to 240.
Thanks for any help
-Greg

 

[Bondo]

Re: 1989 Mercruiser 350. Temp sender and gauge

I have a 1989 Thompson Carrera with a merc 350 alpha one gen one. I replaced all my gauges with new white Teleflex gauges. They look great and all work perfectly except fir the temp gauge. The old one worked great but was fogged over as most my gauges were. I replaced my temp sender with the correct one per merc. But the gauge still doesn't work. All I can find out so far is something about "sender code D required". Any input? Do I have the wrong gauge? My old one was marked with an L and and H (Low Hot) the new one is marked 100 to 240.
Thanks for any help
-Greg

Ayuh,.... At the Sender, with the key "On"... Disconnect the wire from it, 'n ground it out,...
The gauge should Peg,.. Hot...

If it does,... Make sure the T-stat housing is properly grounded...
If somebody changed the T-stat, 'n didn't use a rivet gasket, that might be the issue...

 

[Greg68S]

Re: 1989 Mercruiser 350. Temp sender and gauge

I replaced the thermostat and used gasket sealer. That must be the issue then.

 

[Bondo]

Re: 1989 Mercruiser 350. Temp sender and gauge

I replaced the thermostat and used gasket sealer. That must be the issue then.

Ayuh,.... I bet yer Right....

 

[Greg68S]

Re: 1989 Mercruiser 350. Temp sender and gauge

I have a water pump question as well. When you buy a complete water pump and impeller kit it states on the packaging it's for R/MR/Aplha one drives. I replaced everything. Will there be some gaskets and o-rings that I don't use? This question also apply's to the stern drive gasket kit. With that kit I used the big gasket, the rubber round gasket and the rubber o-ring. But I had other o-rings that did not have homes. And a guide pin that I believe was for an R drive. I wasn't sure about the pin because there was spot for one in the end if the shaft, but when separated the upper and lower unit there was not one in place.
- thank again for any insight into my little mess.
-Greg

 

[Greg68S]

Re: 1989 Mercruiser 350. Temp sender and gauge

I did replace the little o-ring that allows for the oil flow between the upper and lower.

 

[Greg68S]

Re: 1989 Mercruiser 350. Temp sender and gauge

PROBLEM SOLVED!!!!!!!!! I used RTV with the gasket. the sensor could not ground. works great now.