trim not working

[muskyfins]

Getting ready to head in tonight when the trim wouldn't work. It worked fine on our way out. Trimmed up a bit, got to our anchor spot and sat and relaxed a bit. Getting ready to leave, I always bump the trim up and then down before moving to ensure full down/in. Now trim not working up or down. I've already checked a lot of the usual suspects as detailed below.

2000 Rinker FV270 Mercruiser 5.7 EFI Bravo 3

Trailer switch works. But if the limit switch was out of whack, I'd still have down. (which I don't) Is it safe to eliminate limit switch?

If I jump the low voltage terminal on either solenoid, motor runs fine. So solenoids seem good. This also eliminates the 110 amp fuse.

I disconnected the control disconnect/plug and jumpered each connection individually to eliminate any loss of continuity within the connector. No improvement.

Not only did I replace the control wire fuse, I replaced the fuse holder itself because it was looking gnarly. Fuse wasn't blown anyway. New one doesn't blow either.

Removed the switch from the throttle. Jumped the terminals to bypass switch internals. Pump doesn't run..

I moved enough wiring around that I would have figured any worm insulation/short would have become noticeable.

With boatinfo website down, I do't have a schematic. (been looking at them on other websites) But I'm at a loss. What am I missing? As always any help or thoughts are truly appreciated.

 

[Bt Doctur]

Probably more bull sh&t copyright infringement. I just may have to start burning manuals again for sale
http://www.boatfix.com/merc/Servmanl/6/6A5R3.PDF

 

[stonyloam]

OK if the trailer works and up/down does not and the solenoids are working, then I suspect that you are not getting power to the trim switch in the control, but you are getting power to the trailer switch. Not exactly sure how you are set up, but I would look for a bad red wire connection to the trim switch. With a voltmeter check for 12v on the red wire of the switch.

 

[muskyfins]

Ed-thanks for the manual. Actually went through all those checks. In the schematic, I noticed the "second" 20 amp fuse near the controls, but I don't know where it is on the boat. There's really no place for it unless Rinker buried it in the gunwhale. Not that stranger things haven't happened.

Stony-after reviewing the schematic above, I came to the same conclusion. I will check for voltage at the switch tonight, but the switch wire isn't red. Center wire (what I believe to be voltage) is black and each of the other leads are green and blue. I jumped them last night but never actually checked for voltage. Unless the ground is switched??? (black wire feeding switch)

 

[stonyloam]

That black wire is kind of a surprise. Yeah black is usually ground. On mine 12v is fed to the switch. Up makes contact with blue, and down green. Are you sure it is not purple? Anyway there should be 12v there all the time.

 

[muskyfins]

So last night, I went down to my slip. Few notes:

Feed wire on switch is in fact RED. Very nice black shrink tube that is like 2 inches long makes it appear black until closer inspection.

Feed wire HAS 12V power.

Battery jumped directly to green or blue wire on switch does nothing.

Motor and solenoids confirmed ok (see above post)

Trailer switch works to power trim motor.

So I have a loss of continuity between switch and solenoid. How? Where?

I can understand the up function not working if there is a problem with the limit switch. (which I won't know until October. But shouldn't the down functions work at all times independent of the limit switch?

 

[stonyloam]

Hmmm... You might have TWO problems. Need th check them one at a time. If the trailer works then your blue/white wire from the control to the up solenoid is OK. So check that first by bypassing the trim limit. Unplug the the purple/white wire and the connector with 2 blue/white from the black wires coming from the limit switch. With a wire, jumper between the two connectors. See if the trim up works. If it does (it should) you have a bad limit circuit. If it does not, check to see if you have 12v on the p/w wire when you push the up switch. If not then you have a wiring problem. If you get the up to work and the down still does not work, you have a wiring problem with the down. Check the main plug for corrosion. Yes the down should work all the time. See if you get 12v on the switch terminals at the switch, when you push up or down. I am guessing the switch so OK, and your trouble I'd between the switch and the solenoids. Good luck.

 

[Pete104]

I'd start with battery connections. It worked before ya got there but not when ya wanted to leave. How many wing nuts are on your batteries? Get however many in stainless hex nuts and use them on clean connections!

 

[muskyfins]

I have no wing nuts on the batteries. You could eat off my connections. I'm more than a little anal about the condition and maintenance of my equipment.

In any case, per my posts above, I've already established there is voltage at the "power" side of the solenoids and the motor runs. Works fine on trailer switch. The problem is in the control circuit.

 

[jkust]

I'll chime in on this. I had a similar issue a month ago on my boat. Similar though not exactly the same. One day the trim down function on the shift handle quit working. The trailer up/down on the transom both worked. That is the best news you can have because it means it was only a continuity problem or switch problem. After a lot multi-meter testing, I realized I had caused the problem the prior week when I had detailed the bilge and gently rinsed with a hose and was overly generous with the rinse step.
The plug that the shift handle switch runs to which then runs to the transom plug that then runs to the pump was corroded. That is why the transom switch worked and the other didn't. The thing is that the plug prong female end is so skinny that you can't see inside to even tell that there was any corrosion. It is supposed to be water tight but realized that the hose clamp that makes the water tight boot around the plug actually become watertight wasn't as tight as it should have been. You mention that you can eat off your plugs, but so could I have and only cleaned out the female end on a desperate whim having been lead to that as the only thing left after the multi-meter troubleshooting.