Trim Gauge

Mercury · 18 November 2008, 18:15

Hi. I have recently finished installing power t&t on my 50hp. Brown band Mercury O/B. I have just added a trim gauge but the reading seems to be reversed. ie. when the engine is in the up position the needle points to the Down symbol, and vice versa. I have tried adjusting the sender unit, and putting it on the other way round but it makes no difference. Is there anything else I can do, or do I have to live with it.

Nasher · 18 November 2008, 18:17

Try swapping the wires over on the back of the gauge.

Nasher

Mercury · 18 November 2008, 18:49

Quote:

Originally Posted by Nasher

Try swapping the wires over on the back of the gauge.

Nasher

I thought of that, but am a bit reluctant. in case it does any damage. There are Three connections on the gauge, live, earth, and send. I have the Brown wire with White trace connected to send, Purple to live, Black to earth. I am sure this is the right way round, so will it do any damage connecting any other way?

Nasher · 18 November 2008, 18:54

If it was me, I'd try swapping the +ve and -ve over, but its not me, and I wouldn't want to be held responsible for any damage

Nasher.

Ian Sharlot · 18 November 2008, 19:46

Sounds like you have the wrong sender unit fitted to the engine, I would check that one first

geoffs · 18 November 2008, 20:03

Most senders are only a pot, + on one end, - on the other and sig out the middle. Swap the + and - and the signal will be reversed.

Have a look and maybe try that.

Swapping the + and - on the gauge is likely to cause the can of smoke that lives in all electronics to be let off!!!

Dirk Diggler · 18 November 2008, 21:06

Sounds like you've got the wrong gauge. What make is it?

Mercury · 19 November 2008, 15:38

Quote:

Originally Posted by Dirk Diggler

Sounds like you've got the wrong gauge. What make is it?

The Gauge is Mercury Part No. 79-859693-A1. The sender unit is Quicksilver Part No. 821180A3. All Brand new stuff, well it was still in it's box.

Dirk Diggler · 19 November 2008, 15:52

Yeh, I reckon you've got the wrong gauge. The part # you have for the sender is for a 100 & 115hp, but specifically for a Sea Ray. These were a range of motors that were painted white, and I reckon they didn't have Merc instruments, probably Faria or similar. Of course, I could be talking utter Sh*te, but the sender info is correct!

Dirk Diggler · 19 November 2008, 16:17

What side of the motor are you mounting it, coz the parts finder shows it on the port side.

chewy · 19 November 2008, 16:34

Just fit it upside down!

Mercury · 19 November 2008, 18:53

Quote:

Originally Posted by chewy

Just fit it upside down!

Tried that first.

chewy · 19 November 2008, 19:01

Why didn't it work?

Mercury · 19 November 2008, 19:06

Quote:

Originally Posted by Dirk Diggler

What side of the motor are you mounting it, coz the parts finder shows it on the port side.

The power t&t came from a 70hp. Three cylinder Mercury 1993 vintage. It's the Three ram type, ie> Two small rams and One larger ram in the middle. It came with the the mid section and transom bracket complete. The sender unit works off the pivot pin on the end of the large ram. The mounting holes are on the Left hand side of the swivel plate, as you stand at the back of the boat, facing forward. Or if you were sat on the jockey seat driving the boat. the sender would be behind you on your Left hand side.

Mercury · 19 November 2008, 19:09

Quote:

Originally Posted by chewy

Why didn't it work?

It did work, but the readings were still the same.

Downhilldai · 19 November 2008, 19:10

Quote:

Originally Posted by Mercury

The mounting holes are on the Left hand side of the swivel plate, as you stand at the back of the boat, facing forward. Or if you were sat on the jockey seat driving the boat. the sender would be behind you on your Left hand side.

Yep - that's what Dirk meant

Quote:

Originally Posted by Dirk Diggler

.....shows it on the port side.

PeterM · 19 November 2008, 19:16

Can you just turn your head upside down when you read it ??

Or if its always you that drives learn to read it upside down ? Its a free solution !

mr_sav · 21 November 2008, 19:13

I fitted two new trim gauges to my boat to find that they are a croc.

The Needles are not glued exactly in the same spot so the Trim Gauges do not reflect same reading for both motors at same trim.

I am getting new trim gauges to resolve the problem, probably going to be a swap until gauges reflect same trim.

So My move will be to find something nice to fit into the holes and piss them off.

I trust the Tried method of trimining until the props are just biting, or if planing at low speed trim down enough to keep the bow down.

Mollers · 21 November 2008, 19:16

Quote:

Originally Posted by Mercury

Hi. I have recently finished installing power t&t on my 50hp. Brown band Mercury O/B.

Is 50hp enough to drive a trim pump?

alystra · 23 November 2008, 11:26

Mine never worked properly from new and failed in the second season because the sender unit filled up with water. Saw the price of a replacement and decided I'd just turn round and look at the engine. I soon got the feel of it and just have to look occasionally now. That also means I check the cooling tell tale too.