Testing Volvo Penta DP S Trim Sensor?

[Riverseamarine]

Hello All: I am trying to diagnose a problem with the trim / tilt on this unit. There are two switches on the throttle shift lever; one "trim" and the other "tilt". Trim motor is fine. It will operate up / down when jumped at the motor. Relays (two at the motor and two under the helm dashboard) appear to be good - the relays click when tilt switch is operated. The trim switch will operate in the "down" position. but not in the "up" position. Switch is good.
I disconnected the trim sensor (on the top of the out drive) wire harness and the "trim" switch will operate up or down; however the gauge does not register - it is in the full down position with the trim sensor disconnected. Further, only the trim switch is required to operate the out drive through it's full range; where formerly, the trim switch would I am thinking that the sensor is the issue, but can't seem to find any test procedure that is conclusive.
This is a THREE wire unit that has the following colors: White / red, white / black, and white / green. There is no continuity (totally open circuit) between any of these wires with the trim / tilt full up or full down. I am suspecting a faulty sending unit. What puzzles me is that the trim gauge Will register when the sender harness is connected. As my dealer is unwilling to provide any test information, I am reaching out to you.

 

[Scott Danforth]

if you have the square gauge, it is the gauge that triggers the relay for the trim limit.

the test information is in the factory manuals for the drives.

either look up your drive and the right manual here http://boatinfo.no/lib/library.html

or get the right manual from here http://www.volvopenta.com/volvopent...lication_search/Pages/publication_search.aspx

 

[Riverseamarine]

No Title

Thanks for the info. Unfortunately there isn't any info for the model I am working on.
I was able to get information on testing the sending unit. The tests indicated infinite resistance between all wires (open circuit), whether testing fixed resistance or variable resistance; indicating a faulty sending unit, right? What puzzles me is that with the sending unit harness plugged in, the trim gauge registers. Manually turning the gear wheel (rack removed) will cause the trim gauge to go up and down. At the top of the trim range. a relay (under the instrument panel) clicks. That would probably indicate that the sending unit is operating correctly. So why am I not getting any readings on the Ohm Meter? I am attaching some pictures that may help positively identify this Out Drive. I am not sure that I am consulting the proper manual / test procedures. Additionally, of the two relays under the instrument panel, one clicks when the "Tilt" (not the trim) switch is operated and also when the sending unit gear wheel is turned. The other relay seems like it is energized constantly. I have unplugged the relay with the ignition switch on, re-plugged it in and hear a distinct "click". Switching the relays (they are both the same) makes no difference.
I entered the serial number (from the tag located near the inner transom) on a Volvo Penta site and it identified the unit as a TSK - DPS. I am not sure that this is correct, as any of the drawings in the TSK manual are not similar to this Out Drive.
1. Can you help correctly identify the out drive that I am working on?
2. Provide some clue as to why I am not getting any readings on the sending unit when testing?
3. Explain why the sending unit seems to allow the trim gauge to show a reading?
4. Tell me if the constantly energized relay is normal. Should it always be getting power?
Thank you for your help