Trim up only works when tilt is pressed. Volvo DP LK

[slimfitz]

Hello all, I am trying to figure out my trim/tilt on my boat. I have the wiring diagram and am trying to figure out why it will only go up when I press both both the tilt and trim up switches. Trim will not work on its own. I am thinking I might have a bad sending unit. Has anybody ever ran into this issue? The boat in question is a 97 Chris Craft 27 Concept 7.4 Gsi/DP-S drive

 

[Don S]

Re: Trim up only works when tilt is pressed. Volvo DP LK

Test the sender, doesn't matter if someone else has had the problem or not, you do.
Do you have a trim gauge? Does it work?

 

[slimfitz]

Re: Trim up only works when tilt is pressed. Volvo DP LK

Yes the gauge works.

 

[slimfitz]

Re: Trim up only works when tilt is pressed. Volvo DP LK

It is starting to rain outside tonight. I will test the sender tomorrow if we are not getting the hurricane rain when I get home. I am reading the Volvo manual now. It does not give any way to test the trim limiter. How do I test the limiter?

 

[Don S]

Re: Trim up only works when tilt is pressed. Volvo DP LK

If the gauge works, the sender is fine. Sounds like a black box problem. No way of testing it that I know of.

 

[slimfitz]

Re: Trim up only works when tilt is pressed. Volvo DP LK

Do you know if there are any volvo manuals that discuss how that black box operate? Im not even sure on how to set it. I did a quick search to see if I could buy one. I didnt see any. THey are listed as obsolete. What would the drawback be of just wiring it up like a SX drive? I see that they dont even use it on their wiring diagram.

 

[Don S]

Re: Trim up only works when tilt is pressed. Volvo DP LK

I know I had something on setting those things, but so far I haven't been able to find it. About to head into the other computer and see if it's in a file I missed putting on this one.
There isn't anything in the manual, and you were just looking at the wrong wiring diagram.

This is it from the manual

View attachment 7797362 LK Ign, Electrical 81.pdf

 

[slimfitz]

Re: Trim up only works when tilt is pressed. Volvo DP LK

Yes thats the wiring diagram i have. The black box is right in the middle. I was just curious how to set it or adjust it? If all else fails i will cut it out and wire it the same as the SX drives are wired. I am trying to figure out what its purpose is? Is it to just stop the drive before i hit the swim platform?

 

[slimfitz]

Re: Trim up only works when tilt is pressed. Volvo DP LK

Just wanted to say i appreciate your help

 

[Don S]

Re: Trim up only works when tilt is pressed. Volvo DP LK

The DP drives needed the trim limit so people didn't trim too high. You could trim too high and still be running good without loosing speed or gaining rpm, but there was a tendency to cavitation burn on the duo props, so they put a trim limit on them. If you just trim up to best speed and rpm, and then trim down until you just start to loose one or both, then you will be fine, it's when you keep going up higher without gaining that the problems start. If the drive will hit the swim step, you can get spacers for the trim cylinders. That is how it's done now. There is no more black boxes.

Having said that, I did find the file on this computer, just under the wrong kind of drives. So, if you want to try resetting, here is how it's done.

View attachment DP-S Black Box.pdf

PS: I had a DP, without the trim limit, never had cavitation burn either. Just paid a little bit of attention.

 

[slimfitz]

Re: Trim up only works when tilt is pressed. Volvo DP LK

Thank you. This is what i was looking for. I will give it a shot and see if i can reset it first. If not no big deal. I will just chuck it in the garbage. Thanks again Mike

 

[slimfitz]

Re: Trim up only works when tilt is pressed. Volvo DP LK

Quick question. On the wiring diagram. What is the round thing with terminals that the tilt switch (9)runs to? It is directly above the gauge on the diagram. Thanks again. Mike

 

[Don S]

Re: Trim up only works when tilt is pressed. Volvo DP LK

Back of the ignition switch.

Here is a better picture of one from a much newer diagram. Wire colors may vary, but the switch is the same.

 

[slimfitz]

Re: Trim up only works when tilt is pressed. Volvo DP LK

Well it defenitly the black box. I just tried to reset it. I now have movement both ways with the trim switch. I however do not seem to have an upper limit anymore. So I guess I will leave it as is and just watch the gauge. If I have issues I have a jumper wire that I will leave in the boat to jump the motor to make it go up or down. Thanks for your help. Mike