New style gauges replacing old

[jarrad sharp]

Hi all have installed new gauges in to the boat replacing the old that were added and unreadable . I have a Yamaha 115c 2stroke salt water series and the temp light blinks on the new gauge I have checked the dip switches at the back of the gauge and are all set correctly. once I connect the 2 grey cables in the motor cowling it goes into alarm ??????? also the trim gauge is suspect as i trim the motor up an inch it seems to to go nearly all the way up on the scale???????? as this is a common loom from gauges to motor could this be a contributing factor?? When I brought the gauges I also had to get an adaptor lead that would suit the new gauges to the old loom, and now the orange wire in the loom douse not connect in to the new gauge through the adaptor lead??

[rodbolt17]

what is the part number of the gauge's. what is your engine model number ?

[99yam40]

OP, just for your imfo the old gauges can be sent off and repaired most of the time

[jarrad sharp]

Hay rodbolt17 engine model 115CETO 6E5 L 404751 U and gauges model 6Y5-2818R-32

[jarrad sharp]

Hey boscoe99 disconnected the Grey bullet cable behind the gauge and light has stoped blinking and no alarm when reconnecting the cables on the cowling. How can I test that the alarm will still work if motor was to over temp now...???? Is there a way to rescale the trim gauge???

[boscoe99]

Does your tachometer have one four pin connector or two four pin connectors at the back? Here in the US a different part number is used for the multi-function tachometer. 6Y5-8350T-XX is what we use. Mostly.

Are you using an adapter harness between the tachometer and the trim/oil harness?

[rodbolt17]

CETO indicates it is either a non US market engine or an early 1984 or so import.
what are the wire colors on the tach you are trying to use?
does this tach have 3 dip switchs under a rubber cap?
how many wire does the trim sender have?
does this engine have automatic oil injection?

[jarrad sharp]

Hey rodbolt17 yes it is an aus motor 1999. It has 3 dip switches on the back. See pic. I’m sure it is a two wire sender. If I put the old gauge back in the trim gauge works fine but with the new gauge the trim gauge seems to be way off. As I trim out the smallest bit the level climbs really fast compared to the old gauge. I have and adaptor harness to suit the new gauge to the old harness 6Y5-85335-10-00. Only once I disconnect the Grey bullet plugs on the back douse the temp gauge stop flashing and buzzer stops is this correct...

[pstephens46]

Going to wait a bit. Rodbolt is busy with the collard greens. Hang tight.

[boscoe99]

Yep, it is a 1999 model for the non-USA market. Equivalent of a US model S115TLRX or S115TXRX. http://www.boats.net/parts/search/Ya...XRX/parts.html

It uses a three wire sender. Not really compatible with the 6Y5-8350T-90 gauge which appears to be what you have. Reason being is that the -90 tachometer does not provide five volt power for the three wire sender. Which your model has.

Yes, the gray wire is disconnected. See diagram below. Also a note about the trim gauge. One clever fellow in your predicament reported that he bought a five volt power supply and used it to supply the sender with voltage.

[boscoe99]

Something like this I think.

https://www.ebay.com/i/131199957529?chn=ps

https://www.superbrightleds.com/more...CABEgL4DfD_BwE

[jarrad sharp]

Thanks thanks boscoe99 we’re would I connecting the 5 volt supply to????. Is there a way to trick the temp sender to trigger the alarm to test it is all ok with Grey wire disconnected???

[jarrad sharp]

The trim gauge works in 2 wire mode but not 3 wire is this due to the 5 volt problem

[boscoe99]

Is there a way to trick the temp sender to trigger the alarm to test it is all ok with Grey wire disconnected???

Find one of the two thermoswitches on the motor. One on each cylinder head. Disconnect the wires to the switch. Then jumper the pink wire to the black wire on the engine harness side. Turn the key on. The alarm should start sounding. The over temperature icon on the tachometer should be flashing.

[boscoe99]

The trim gauge works in 2 wire mode but not 3 wire is this due to the 5 volt problem

If it works fine in the two wire mode then so be it. I don't think it will really be accurate. Not as accurate anyway as using the sender as it was designed to be used. Some people don't use their trim gauges. Some don't care if it is not spot on.