Overtemp Indicator

[Elwood22]

I thought I read on here that grounding the gray wire on the MF tach should cause the indicator to flash. Is that right? If it doesn't, does that indicate an issue with the tach? Would an incorrect dip switch be the problem? This is a 93 TXRR.

[fairdeal]

on my MF tach, grounding the gray wire does nothing visible
the green/red makes the temp lamp blink
the green/white makes the oil lamp blink
mine is set for 4 stroke

[Elwood22]

Current dip switches are OFF-OFF-OFF. If I bypass the thermoswitch, I get an alarm, but no over temp indicator.

[rodbolt17]

back when that antique was built the overtemp icon was in the speedo. so it is going to depend on the tach,the wireing and are you doing it right.
I don't have my guide here but set the tach for 2 stroke,12 pole 3 wire trim.

[Elwood22]

OK - thanks. So my switch settings are correct. I have checked continuity from the black/gray lead at the thermoswitch all the way to the gray terminal in the trim harness connector at the tach - all good. There is a second gray wire spliced into the gray wire from the tach to the trim harness. The second wire may be an issue. I will have to figure out where it is coming from. I guess since the oil indicators work, if I get an alarm and the oil is good, I can assume the problem is overheat. It irks me that I can't get this thing to work though.

[rodbolt17]

on the TXRR the gray is tapped into the pink at the engine. anytime a thermoswitch closes it apllies a ground to the gray wire. that gray wire should not go to any other circuit. green/red is ground for the low engine tank visual,green/white is for remote level ok or not.

[Elwood22]

Right - the pink at the thermoswitch goes into the black/gray wire that connects to the the gray wire in the trim harness. I have verified continuity all the way through to the tach, so the tach should be seeing ground. And when I applied ground directly to the gray lead on the tach, it did not respond. When I power up, the tach does a self check and the overtemp indicator comes up with the others, but that's the last I see of it. I am still wondering about the second gray wire. Unfortunately the boat is 85 miles away, so I'll have to wait to play with it. Is it possible that the motor has to be running for the indicator to function? I have been doing key on.

Fair Deal - you said grounding the gray wire on your tach didn't have an effect either. Do you get an indicator if your motor overheats?

Thanks guys!

[boscoe99]

Can we get a photo of the tachometer please? There are Yamaha tachometers and then there are Yamaha tachometers. I am not sure that we are all singing from the same hymnal.

[Elwood22]

I don't have a photo. I wish I had thought to take one. The model number is 6Y5-8350T-83-00 TACHOMETER ASSY RND.

[boscoe99]

I don't have a photo. I wish I had thought to take one. The model number is 6Y5-8350T-83-00 TACHOMETER ASSY RND.

Why didn't you say so in the first place?

The gray wire from the tachometer is for the over temperature indicator lead. Grounding the gray wire lead will cause the over temperature icon to flash.

[Elwood22]

That's what I thought - but it doesn't. That's the issue.

[boscoe99]

That's what I thought - but it doesn't. That's the issue.

Well it won't in the four stroke mode but should in the two stroke mode. You can tell if it is in the two stroke mode by the presence of bars under the oil pot icon.

I presume you are grounding the tachometer gray lead directly at the tachometer. From the black lead that comes from the tachometer. If the over temperature bar does not start flashing then that functionality of the tachometer is inoperative.

[Elwood22]

OK - I was grounding it directly to the ground post on the fuse block. When I go back down there I will play with it some more. I may just have to do without it. Thanks again for the help.