Volvo Power Tilt not working

[jeppsG8]

I've searched extensively and can't find the same symptoms I'm having. Hopefully someone has a suggestion.

2000 Mariah Shabah Z212
Volvo 7.4 Motor
Volvo Penta Duoprop Drive

I put the boat up for winter in September, everything was working fine. Today I got it out with plans to put in on the water tomorrow and the tilt will not operate. Tried both up/down and the switches on both the rear transom and the front throttle control. All inline fuses seem to be okay. Checked the relays and both seem to be okay. I measure 12v across the constant positive and negative on both relay sockets and I measure 12v between the wire coming out of each relay (blue/white from one and green/white from the other) and the negative terminal on the battery while measuring and pressing the tilt switch. So I really think the pump is siezed up, but I'd like some validation before I start trying to repair or replace it.

Does anyone have any ideas? Is there something else I can try?

 

[Bondo]

Re: Volvo Power Tilt not working

So I really think the pump is siezed up,

Ayuh,... Hot wire it from the battery, 'n See if it works...

If it Does,...
Clean the wiring ends... they're probably abit corroded...

 

[jeppsG8]

Re: Volvo Power Tilt not working

I hard wired it and the pump works fine. Both directions depending on the polarity of the connections to it. So I can rule out the pump itself.

I went ahead and replaced both relays this morning and it didn't help. I'm not sure how I can measure voltage at the pump connector when I press the trim switch, and I can hardwire into the same connection point but on the pump side and it runs. But when I connect the two and press the trim switch I get nothing.

I will try to clean the connectors again but this one has really got me perplexed.

 

[Don S]

Re: Volvo Power Tilt not working

To test the motor only, in the drawing below hook jumpers to connector C and go directly to the battery + and - terminals. It's a reversing motor, just reverse the wires to run the other way.

 

[Don S]

Re: Volvo Power Tilt not working

Looks like I was posting at the same time you were. Try this.

 

[jeppsG8]

Re: Volvo Power Tilt not working

Thanks Don. I will walk through this. One question is the 50a circuit breaker it is talking about. Is that the 50a red capped button on the front side of the motor? I think it is connected to the exhaust manifold.

 

[Don S]

Re: Volvo Power Tilt not working

It could be, what is the full model number of your engine, or the VP serial number.

Check at terminal G and see if you have power and ground.

 

[jeppsG8]

Re: Volvo Power Tilt not working

Engine is a 7.4GI PEFS. With s/n 4012011106 3869060

Just checked and I have 12v at connection G. Also verified that terminal G connects directly to the 50a breaker on the front of the exhaust mani so it is the one I thought it was.

 

[jeppsG8]

Re: Volvo Power Tilt not working

When I apply power directly to terminal C, the motor runs.

When I test voltage directly at terminal D, I get +12v with switch up and -12v with switch down.

When I connect terminal C to D the motor doesn't run in either direction. Could it be an amperage problem that I'm not catching when I test for voltage at terminal D?

 

[Don S]

Re: Volvo Power Tilt not working

Could it be an amperage problem that I'm not catching when I test for voltage at terminal D?

It could be. Are any of the connectors in the system corroded or loose?

 

[jeppsG8]

Re: Volvo Power Tilt not working

Are any of the connectors in the system corroded or loose?

I don't think so. I ran it up via direct connect to battery so I could get it out of the garage. I hooked up water and started up the engine with no problem. I've tested all other electrical that I can think of (bilge, hatch, anti-corrosion system, antennas, all lights, etc.). All work without any problems. But the trim still didnt work. So I know I've got plenty of battery and solid connections for ground and primary battery switch.

Is there a separate fuse behind the front trim control (the one on the throttle)? And if so, could that be a problem that would cause both switches to not work? I'm thinking there might be an amperage draw if one of the two switches are bad or not connected. Doesn't make logical sense to me, but I'm beyond my ability to think logically about this any more.

 

[Don S]

Re: Volvo Power Tilt not working

Give me some time to make up a troubleshooting chart to go with the picture. May make it easier than trying to follow the Volvo info.
How did you check the relays?

 

[jeppsG8]

Re: Volvo Power Tilt not working

I measured across the leads while they were out. Measured 75.9 ohms where the guide said it should be between 70-100. All other connections showed either continuity or no continuity where it should have. I did not do the tests that needed the relays to be plugged in while testing. But, I did replace both relays as a blind attempt to correct it. Same result.

 

[Don S]

Re: Volvo Power Tilt not working

Here are some abbreviations I will use. BV= Battery Voltage, R=Red, B=Black
You may want to print out the picture below, makes it easier to follow.

1. Hook up your meter for 12V DC B on the negative terminal of the battery, with the R lead, check relay sockets 30 on both the up and down relay. Should show BV. Next with the R lead touching a 30 terminal on the relay (doesn?t matter which one), with the B lead touch each of the 86 and 87a terminals in both relay. Should show BV on all terminals.
If this all passes, you have good power and ground from the battery.

2. Hook the B lead to any one of the 86 or 87a terminals. With the R terminal of the meter touching 85 of the up relay, have a helper push the trim up switch. You should see BV .
Repeat process on the other. Repeat with the down relay and the helper pushing down on the buttons.
If you show power on both, then the trim circuit is working.


3. Next you will need two jumper wires with male spade terminals on each end.
On up relay jump between 30 and 87, on the down relay jump between 87 and 87a. The pump should trim the drive up.
Next, On the up relay jump between the 87 and 87a terminals and on the down relay jump between the 30 and 87 terminals. Drive should trim down.

If all of the above checks out, you have a faulty relay or two.

 

[jeppsG8]

Re: Volvo Power Tilt not working

Thanks for the step-by-step. Much easier to follow than the manual.

I have walked through it twice but get strange results. The first time, Step 1 and 2 worked great. Step 3 failed. Aftery trying step 3, I went back and did step 2 again using the other trim switch (the one on the stern). Step 2 didn't work that time.

So I tried something different. I disconnected terminal C from D. Ran longer leads into terminal C and tried a few things. First I put one of the leads in socket 30 and one of the leads on the neg battery terminal. Motor worked. I moved the neg lead to engine block and again motor worked. I moved the neg lead to socket 86 and 87a and the motor DID NOT work. Upon further testing I could not get continuity between socket 86 or 87a (on either relay socket) and the engine or neg battery terminal.

So now I am thinking that I have a faulty ground connection to the relay sockets. I traced the grounding cable from the engine grounding post to a ground distribution block and all cables appear clean and tight. I have good ground on all connections there. So I wonder if I have a broken/shorted ground cable between the groudn distribution block and the relay sockets. I will need to remove the socket assembly to get a good look at it. But my back, knees, and shoulder finally gave out and it will need to wait until tomorrow. Great way to spend the 4th.

Thanks again for all of your help. If you have any ideas about where a likely failure point might be on the ground please let me know.

 

[Don S]

Re: Volvo Power Tilt not working

Have you noticed any corrosion on any connections? If they aren't a bright copper color, they are suspect.

 

[jeppsG8]

Re: Volvo Power Tilt not working

Have you noticed any corrosion on any connections? If they aren't a bright copper color, they are suspect.

I have noticed several that are more white/grey colored than copper. I will take the opportunity to clean as many of the connections as I can while I am tracking down any possible grounding issue.

 

[Don S]

Re: Volvo Power Tilt not working

White/Gray IS corrosion

 

[jeppsG8]

Re: Volvo Power Tilt not working

Hi Don. Happy 4th. I've spent my day again in the boat. Good news is I found it and got it fixed. Thanks again for all of your help. Ultimately it wasn't any corrosion, relays, or fuses. It was a damaged cable between the grounding point on the back of the engine block and the connection by the 50A circuit breaker. It had a good enough connection so I could measure 12V at connection D, but it couldn't draw enough amperage to run the motor. What a royal PITA!

I ended up cutting out the bad section and splicing it back together. I also rerouted it a bit and secured it hopefully to avoid this ever happening again. Thanks again for your help. I know more about the system now than I ever wanted to.