Hi I have a 08 250 pro xs and the trim gauge stopped working.
Does anyone have a suggestion on where to start troubleshooting?
Also the Speedometer at rest reads 20mph and when traveling above 20 mph it is low by about 8 mph. anybody have a suggestion on where to start troubleshooting.
Before we begin..... need to determine which "type" of speedo and trim gauge you have.
Are they ANALOG or Smartcraft?
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 48 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
Hi
Speedo is hooked up to a black tube pressure fed I would assume
Trim is analog Merc 08 250 proxs Triton
Not Smartcraft
Speedo:
This should be connected to a black hose that "tees" between the gearcase and the Speedo (pitot) sender. "Tee" kits are available to add, if necessary.
Trim:
Disconnect the brown/white wire coming from the sensor into the engine cowling.
Turn the key "on". The gauge should read "DOWN". Jumper from the HARNESS side of the bullet connector to engine ground. The gauge should now read "UP".
If your results match the above, you either have a bad trim sender, OR you have a continuity ground strap broken at (or under) the port side lower mount cover. To rule out the ground- simply reconnect the trim sender, and provide a temporary connection to ground for the trim sensor's "black" wire. If the gauge now functions properly- locate and repair the missing "continuity ground" on the port side lower engine mount.
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 48 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
Hi Don Thank you for the info
Speedo found the black hose that goes to the pitot sender and is connected to a thicker rubber hose with a coupling. I did not find a Tee. I opened the coupling and the hose to the pitot is clear,but found that the hose to the speedo head had water in it. Blew it out
What is the purpose of the Tee Kit ?
Trim Found with the trim wire disconnected the trim gauge red full scale up and when shorted to ground read low scale Down
Ran trim/tilt all the way down guage read down ran trim/tilt all the way up read full up.
Question I thought the trim guage would show the trim scale movement only not the trim/tilt. So the trim is only the bottom 1/4 or less of the guage ?
Sorry for the basic question New boat
Eric
The "tee kit" for the speedometer would allow for the DIGITAL (Smartcraft) speed sensor (just below the starter) to be connected (as well as an analog speedometer such as you described). If you continue to have difficulties with the speed, I'd recommend you simply replace it. More than likely, there was water in the line that froze over the winter, damaging the gauge.
On Mercury Engines, the trim gauge reads the ENTIRE TRAVEL of the engine (from full down, to full TRAILER/UP position). So in most cases, the "usable TRIM range" will be from the "DOWN" position, to approximately 1/4 on the gauge.
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 48 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
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