Just Bought a 97 175 Tachometer, Oil Pressure, and Up Down gauges do not work

[97Alpha175]

I just bought a 97 175 5 series and some of the gauges do not work. I can not find any links to fix this. Oil pressure and up/down gauges do not work. The tachometer works, but can reads high intermittently.
Speedometer seems to be a few mph short of my cellphone GPS.
I am guessing I have a broken wire maybe, or adjustments to be made?
Any help would be appreciated. I want this boat in tip top shape (safe), but careful how much money i put in it.

Thanks in advance!

 

[JimG]

To start with, take the gauge panel off and clean/tighten all connections.
You may need an oil pressure sender... easy to change out.
You're lucky the speedometer works and is that close.

 

[Hoplite808]

There is no one easy or usual fault with the items you described. Your going to have to troubleshoot them each individually.

For the oil pressure you will have to test the gauge and the sender for the correct ohm’s to make sure they are what’s wrong or not. There could also be a break in the sending wire so a continuity test from the sender the the gauge is also needed. Sometimes the ground is just bad on the gauge cluster.

For the tach you’ll also have to look up the specs and test everything to find the fault.

The speedo works via a vacuum tube from the sender on the transom or integral to the drive depending on the setup on your boat. If it’s close that’s good enough so don’t mess with it.

The trim gauge again you need to troubleshoot everything. Check the sender wires for the correct ohms and if good test the gauge if that’s not it test the power lead and ground and also the sending wires for continuity all the way to the transom.

 

[Pirate Lady]

I just had the same tach problem last week, on back of tach there is a flat dial, with a flathead, turn 180 left, back to original position, turn 180 to right, return to original position. Black (4 o’clock) on picture. Worked for me. Will try to find the thread.
Boat speedo before built in gps are not very accurate. Your phone is better. Download app SpeedTracker. Works great on boat.

 

[Pirate Lady]

Go to Classic SeaRays / Tachometer acting weird.

 

[Pirate Lady]

Trim gauges break so frequently most just give up. The sensors on outdrive underwater take a beating. I just had mine replaced last August. I doubt they will work in a year.

 

[97Alpha175]

Wow, this is great info, thanks everyone. I will pull the gauge panel and start with some basics wire tracking. I will follow up on how it goes.
Pirate Lady I could probably live without the trim gauge, but I am having trouble hearing when it is all the way down. If I hold the down button the trim motor just keeps humming after it is down (and up). So I don't want to keep holding the button, unless that is not bad.. I am a completely new to boating lol.
I will probably fix it at least once haha or learn some trick and then who cares.

 

[Pirate Lady]

All I ever had made a very distinct noise when it reached the upper and lower limit. Not a noise like a click. More of a sound like hitting resistance.
With boat out of water. Put drive all way down, then do a count till full up. Do same in reverse. Repeat a couple times. When in water, count.

 

[97Alpha175]

That sounds like a plan! I can hear the noise when it hits the stop going up even with the motor running, but down is hard. The water is very dark too where I am starting out so it is hard to see the motor under water.
Someone I think bypassed the "trailer" button on the throttle, so I am not sure if that disables the trim gauge. I have not read about how important the trailer button is, but I know a lot of people bypass it.

 

[Bill Curtis]

Here is the Telflex manual on their gauges (The Sea Ray gauges are the same, basically).
Near the end is a troubleshooting guide. Trouble shooting is straight forward and can be as simple as lifting a lead off / or shorting the sensor lead to ground to tell if it's the sender or the gauge. Look on page 330 and it will explain.

If someone bypassed the trailer button, that can be a big issue. If the trim / trailer sensors on drive are kaput, they should be replaced. The trailer position switch and / or sender has no bearing on the trim sender / gauge, as they are separate. Replacing them is a huge PITA, but can be done by a DIY type person.

I have the Mercruiser manuals showing how to if you need them.

 

[blaster]

Check the pig tail connection at the engine. Make sure that there is no corrosion and reconnect after adding some dielectric grease. Super easy to do.

 

[97Alpha175]

Here is the Telflex manual on their gauges (The Sea Ray gauges are the same, basically).
Near the end is a troubleshooting guide. Trouble shooting is straight forward and can be as simple as lifting a lead off / or shorting the sensor lead to ground to tell if it's the sender or the gauge. Look on page 330 and it will explain.

If someone bypassed the trailer button, that can be a big issue. If the trim / trailer sensors on drive are kaput, they should be replaced. The trailer position switch and / or sender has no bearing on the trim sender / gauge, as they are separate. Replacing them is a huge PITA, but can be done by a DIY type person.

I have the Mercruiser manuals showing how to if you need them.

Thanks for the info everyone!! I would definitely like to have the service manuals. Bill Curtis, do you have a PDF or are you trying to pass on your books? Either way please let me know. Thanks

 

[Bill Curtis]

Thanks for the info everyone!! I would definitely like to have the service manuals. Bill Curtis, do you have a PDF or are you trying to pass on your books? Either way please let me know. Thanks

PDF versions. Sending you a PM

 

[Bill Curtis]

This document will go well with the picture above