Trim gauge questions
 

My Gaffrig trim gauges always spike the needle all the way up when I turn the key on. When I started trouble shooting I noticed that the wires from the sending unit on the drive (the starboard side sender) have been cut and lead to nothing.
Is there somewhere else to get this trim reading from or is the guage just hooked up wrong. (It hasn't worked since I've had it.....last owner claims is worked prior to my test ride).

Also, have a wiring diagram for Gaffrig trim guages?

Gracias.

Re: Trim gauge questions
 

The sender on the drive is a merc part. It is tough to replace without removing the drive, but it can be done.
The way to do it is to attach the new wires from the sender to the old wires and pull them through the transom assembly.

If yours are cut, then you may not thave this option.

Re: Trim gauge questions
 

There are two senders on a Bravo gimbal. The port side sender is for the trim pump limit switch. The starboard side is what controls the gauge. The sender has two wires, one goes to ground and the other to the sending unit post on the back of your gauge. So depending on what sender has the wires cut, the trim gauge may not even be hooked up. If the limit switch sender is cut, someone has wired the pump direct. If the trim sender is cut, you'll need to replace it for it to function properly. There's no way the trim gauge can work without it. If you find that the sender is wired correctly and is adjusted correctly the gauge is probably bad.

Re: Trim gauge questions
 

Seems like someone would come up with electric indicators for tabs and drives ( maybe there is already?) ...I would consider converting over from mechanical ...4 less cables ...less weight ..less clutter .....almost the same type of display that would show drive and tab posistion ...

Re: Trim gauge questions
 

We already manufacture a kit that would work on tabs or drives. Go to www.danamarineproducts.com, click on products, scroll down to trim systems, click on HP tabs, there's an LED indicator kit listed. You run short 33C cables from the tabs through the transom into my computer board. From the computer board to the dash it's all electrical and the panel is much more compact compared to mechanical gauges.

Re: Trim gauge questions
 

Sweet ....there is another thread http://www.offshoreonly.com/forums/s...ad.php?t=99383

member talking about designing a memory system .... button for tabs up ...button for normal cruise.... about 3-4 in my case .... great great ideas ....

Re: Trim gauge questions
 

ctadams,

check with a flashlight to see if the other ends are dangling inside the drive bellow area. you could then resolder and shrink wrap them and be good to go. I had to do this from wires fatiguing and getting pinched.


DMP,
do you use a voltage regulator for your transducer setup. is the led output 10 discrete lights, or a numerical value. I am interested......
what is the output to the LED fixture.

may be a quick way to go.

Ramb

Re: Trim gauge questions
 

On my TRS both sets of wires were cut just inside the transom as the drive trim and tabs use the std 4 in stroke cable with mechanical indicators.

Not so good for out of channel idling up to islands where the water may only be 2 feet or less 200 yards from shore. [and you can't see the bottom because the water be dark with tannic acid, mon.]

After position "6" on the drive indicator, the drive is still lower than the bottom of the boat. by 6". continuing to trim up is in blind unless either you or your "trained mate" puts an eyeball on the actual drive position and knows when it's right.

At least with the mercrusier trim gage, you could mark the dial when you hit the majic position of just far enough but not too far. (I guess Reggie didn't think I needed Drive Trim limit switches either).

Re: Trim gauge questions
 

88fount33

are the merc pucks on the drives?. (although not being used presently?)

you could use the trim limit pucks and dial them in so they stop your drives at that "clear 2' of water at idle" position

my guess is the drive trim wires are just jumpered in the engine compartment. you could add the limit puck back into the circuit.....just an idea.

i used this approach to set my limits to the best trim for top speed. ( less than the merc max trim spec designed to save the ujoint). I just plane off and run the buttons right to the limits. one gets there slightly before the other but i know i dialed them in to end at the same trim. no watching or thinking needed. (poor man's one position memory :D )

Ramb

Re: Trim gauge questions
 

Ramb,

Wished were that easy, yes both pucks are there and wires connected to the pucks to the outertransom plate, while looking inside the hatch towards the transom, with a strong light, you can see the four (4) wire ends on the starboard side of the inner transom plate clipped too close to the transom plate to reach with strippers, would have to replace the transom wiring to the pucks for this to be connected.

Had an idea to reposition the drive position Cyl on the drives so that my new "6" position is the location for idle speed. Then I will loose the location where I like to run the drives with the tabs up, as the sweet spot for Cruising for me is position 2.5 currently (3.0 for me and the boat porposes at cruise speed, as I do not like running in smooth water with any tab at all). Moving the location for the drive will then cause my 2.5 to probably then go to "0" or less than "0" with no indcation so I will have to make sure the drives are "in" by listening to the trim motors before attempting coming on plane, (best with tabs full down and drives full in).

Back to original post, cut wires to transom mean the gages never worked.

Re: Trim gauge questions
 

Be a real man and snip ALL the wires you can find.
Who do those electricians think they are anyway?
Does anybody really care what gauge readings are?
I find my enjoyment of boating is much better if I have no idea what's going on with the engines. Why worry?












Before you snip any wires just check today's date.

Re: Trim gauge questions
 

Edd just wanted to post whore to get over 1000 !!!! :rolleyes:

not to beat a dead horse 88Fount33, but if you loosen the outside cable wire plate covers (tucked way the crap in there) you could pull the wires tight while you spliced and shrink wrapped, then pull them back until the splice hits the transom and get the proper slack back again on the outside??

just a suggestion, but may be more trouble than worth.....

liekwise, ctadams. if you have the guages, and the wires and pucks are there. then you could re splice to make them work again....

like dana marine mentions - 12V goes to the guage, out the guage, to the sender (potentiometer/resistor) and back into the boat and to ground. depending on the potentiometer position, the resistance shows up via the REMAINING voltage drop through the gauge. so if your gauge is pinning, that tells me that the other end of the wire is grounded somewhere.

Ramb

Re: Trim gauge questions
 

I learn something new about boating everyday. I learned that I do not have Gaffrig Gauges even though they say Gaffrig Performance Instruments. Who would of thought that it is really a Livorsi.
Anyway there is a resister on the back between the signal wire and the + hot wire. What's that all about. The signal wire should have a reduced voltage since the puck on the drive varies the voltageas the drive rotates. Right???

Re: Trim gauge questions
 

There's a whole other string about Gaffrig by Livorsi and Gaffrig.... who ownes the name etc.....

anyway. this is where my first hand knowlege ends, but my logical assumption is that the resistor gives some internal gauge resistance when the puck is at 0 or minimum resistance, otherwise your current condition would not only pin the needles, but result in a dead short and then smoke and heat and stuff....... :eek:

now, this will show my ignorance..... is the guage an ammeter maybe? and negligible voltage drops occurs across the gauge pins? current controlled by the puck resistor, otherwise the resistor is a calibrated shunt ( precision resistor) needed to calibrate the meter.


just my assumption.



Dana Marine????


Ramb

Re: Trim gauge questions
 

Just got back into town, I will get the required information regarding our LED kit from my electrical engineer Monday am.
Thanks

Re: Trim gauge questions
 

It's definatly a trim gauge. What you are saying makes sense.
I had to drop circuits class the first time around so electical issues require some extra though... :p

Re: Trim gauge questions
 

I don't think it measures voltage. I think it measure ohms of resistance to change the gauge readings.

Anybody sure of this?

Re: Trim gauge questions
 

Yes it measures resistance, the trim gauge measures the resistance from its wire to ground as the unit moves. The sender has a contact that wipes along a coiled wire in the sender, as the wiper moves along the coiled wire the resistance either gets higher in one direction and lower as the wiper moves toward the other end of the coil.
When I replaced mine the wiper had worn though the wire and lost contact to ground. I did get it replaced without removing the drive, but it was tricky. I tried to solder the wires once and shrink wrap, but being in water constantly, it just corroded and broke again. I have a set if you want to just replace both the trim and tilt senders.

Re: Trim gauge questions
 

rlsage

Looks like both of my senders change ohms as I rotate the puck so I think I will look into bench testing the gauge itself and then send them back if that's the problem.

Thanks!

CTA

Re: Trim gauge questions
 

Looks like my problem has to do with the factory wiring vs. the wiring harnesses that are on the transplant HP500s. I think the Trim wires ran through the engine harness and through the Mercathode on HP 500 equiped boats but origionally (according to Chris Craft diagram) the sender wires would have went straight to the sender.
Anyhow, I wired the sender straight to the gauge and the starboard side now works. Port side I am still having problems but it looks like the resister on the gauge is broken so I may just send that one back for repair.

Later,

CTA

Re: Trim gauge questions
 

CT

on the remaining drive. did you remove the puck and rotate by hand and make the gauge sweep properly?

in many cases (including both my drives) the bolt behind the puck rotated. (backed out a little) this is one of the reference points for the puck, so being rotated makes the gauge loose calibration and pin or not sweep at all.

if it's not a new boat, check the torque on the pivot bolt behind the puck......
If it happens to be stripped (another common problem) i have a solution......


One last thing - switch the wires and see if the starboard gauge (working gauge) will read port position properly. It may save time and expense trouble shooting before sending out the gauge.... if it is an obvious resistor brake... then...oh never mind my babbles :D

Ramb

Re: Trim gauge questions
 

Thanks Ram,

I did check the puck and it worked fine. In fact I could force the gauge to work by jiggling the resistor. The resistor had some freyed wires so that will surely cause some false readings out on the water.
Also I realized that my boat has multiple purple/white wires so once I located the correct one, things started falling into place.
It will be much nicer this summer knowing where those drives are at as I'm bouncing over the LOTO waves.

Thanks for everyone's help. The suggestions I've recieved off of this message board have saved me much time.