Low Voltage

[tomloans]

Thank you Leon. A thought occurred to me. The voltage drop is not as severe as when it is running. I think I am having another part in the motor eating voltage while the motor is running. Is there a way to test the low/high pressure fuel pumps? There is quite a bit out in these forums pointing to a pump using up volts and the trim/tilt just simply frustrating the matter further.

[tomloans]

Leon what do you mean by "console"?

[lpugh]

Yes with a quailty ampmeter connected in series with the pumps or using a low current probe, though I would be very surprised if they were causing your problem as you described. Also keep in mind the low voltage at the dash gauge may not even have anything to do with how the motor runs. What is important is the voltage at all the electrical points for the motor. It wont take long to drop test at the various powerpoints.

[lpugh]

Leon what do you mean by "console"?

The dash area

[EuropeanAM]

Thank you Don and thank you Leon.

OK so an update. I put the meter on the battery and at full charge, it is reading almost 13.5 volts. When I hit the trim, it moves about 1/2 volt, the same goes for the hydraulic motor ( which frankly appears to be the exact same motor ). They load the battery identically so I don't think this it is my trim motor as it is drawing exactly the same amount as my one year old BoB's motor for my hydraulic jack. At the same time, my dash gauge shows about a 1.25 volt drop for the trim and about a 0.25 volt drop for the hydraulic jack. Remember my handheld voltmeter is showing an identical relatively minor drop for both and perfectly normal while the gauge is showing a serious drop just for my trim motor. I tested it with two different meters with the same results. I turned the key to the on position to see if there is a difference and same results.

What's happening here? Total confusion in the brain at the moment. lol I just removed all the cables and cleaned them with a wire brush as you suggested above. They were super clean already because I cleaned them about 6 months ago. I will take a look at the electric plate too.

The results were excellent on the load test as I compared the starter battery to 3 other batteries as a base and all four batteries produced excellent and nearly identical results. Hardly can tell the difference between the results. I don't remember the numbers Don.

Good grief is all I got to say. Let me check the plate and I will be back to you soon. I did search here and here is what happened to one guy who is on this site....




What do you think about this Don? Can there be a draw from another part of the engine reducing the voltage to a point where when I kick in the trim it is just too much. Why doesn't the hydraulics motor cause as much trouble though. Same motor and draw!

All of the readings you are getting at the console gauges are coming from the engine in one form, fashion or another.

Voltage drop on analog gauges may be significant as there are dozens of feet of extra cable involved there.

Smartcraft voltage comes from the lower of MPR voltage or PCM Wake circuit (Ignition PURPLE wire) voltage. The later also has significant lengths of cabling involved.

Look at the items I recommended checking, especially the engine grounds. But definitely ALL of those items. This type of problem can easily get you bogged down in highly technical circuitry tests when the end result is almost always a simple, poor connection.

[lpugh]

Find the problem yet TOM

[tomloans]

Leon,

I can't find anything wrong. Bought a new trim motor and put it on. I thought maybe under load and in the water the trim motor is drawing too much. Otherwise I am virtually dumbfounded. All connections are super clean and tight.


Hope to take it out and give it try this week. We will see if this solved the problem.

Thanks for asking Leon. I appreciate that. I will post again once I get results.

[tomloans]

OK here is the latest. Took the boat out with my new trim motor and it works great and is virtually identical to the hydraulic jack motor. BUT no change. Here is the bottom line my hydraulic plate and trim motor according to my multimeter is draining 0.50 volts. They are exactly the same. Yet my analog and my digital smart craft is showing a 1.5 volt drop on my trim and 0.50 volt drop on my jack. My jack voltage on the smartcraft concurs with my multimeter but the trim does not. Low voltage alarm is coming on and killing the engine if I start trimming to early. At 4000 rpm no problem as the alternator overcomes the massive voltage drop at those rpms.

Is the motor relying on the incorrect readings of the smartcraft to respond? Smart craft is showing 11.2 when my multimeter is showing 12.3.

Help I am tired now. Lol

[Jtreed99]

I had similar findings on battery vs smartcraft. When I check at the motor leads the multimeter reads identically to smartcraft.

[tomloans]

I had similar findings on battery vs smartcraft. When I check at the motor leads the multimeter reads identically to smartcraft.

Did u have the low voltage alarm going off?

[Jtreed99]

I did not. I only checked because it was turning over slower and the battery was checking ok. As far as I can tell it was just the 26 degree mornings because mine seems fine now.

[lpugh]

Tom I just called you and it went to a message, call me 916 813 0321
If You want to take a 1.5 hour drive to sacramento tomorrow, I will be glad to take a look at it with you, bet I can isolate the problem in less than a hour. As well as give you valuable pointers on diagnosing and voltage drop testing. It really us very easy and quick to do. But it is so much better to watch it being performed and explained in person. No charge for this at all, be glad to help.

[tomloans]

I did not. I only checked because it was turning over slower and the battery was checking ok. As far as I can tell it was just the 26 degree mornings because mine seems fine now.

OK thank you.

[tomloans]

Will call you soon Leon.

[tomloans]

OK guys! Pay close attention to this post before you do anything else if you have a voltage drop due to the trim motor. Problem has been solved because of repeated attempts by Don to get it through my head. I missed a step! A very crucial step. Tonight I started doing searches for a cure for this issue (again). Here is what kept popping up....

-Common ground point on electrical plate (just left of relays): Clean and restack. Remove 3 bolts securing place and ensure the surfaces are clean/grounding well.

and again this from a different post....

-Verify ground wire connections for the trim harness (bundle of ground wires below ECU, at the back of the electrical plate) are clean, and tight- with no paint or liquid tape "leached" in between the connections.

and many other posts fROm Don.

This comment was popping up everywhere and I hadn't done it. This is where the ground wire for your trim motor is located. Bad ground here and you are done.

Took ground wires off the plate and there was a small film of corrosion at all connections.IT IS HARD TO SEE THE CORROSION - BRUSH ALL CONTACT POINTS ANYWAY. Removed the 3 bolts holding the plate against the block and there was corrosion. Took a brush to all sides of the 3 areas of where the plate connects to the block and to the 3 ground wires and where they connect. As you do this you will see white dust which is the corrosion coming off. Tightened everything back and should be good for another 10 years of this motor.

Perfect voltage now. All is well. Now I can fish in peace. In this case the problem was a bad student of Don's.

Thank you all for your help and a special thank you to both Leon for encouragement and Don for sharing all his experience here. I would have missed the spring bite if it weren't for this forum and his input.

Tom

[SilverFox579]

This is why I'm a member here, the incredible knowledge, and willingness to share it, from the best. Happy to hear you got it resolved Tom.

[EuropeanAM]

Glad to hear you managed to get those cleaned up and it resolved your problem. Real easy to overlook that area, but it's critically important in a polarity-reversing, relay-driven DC circuit.

Good job!

[lpugh]

Just like Alka Seltzer used to say in their adds (Oh what a relief it is) Good job Tom

[tomloans]

Thanks guys again for your help. Took it out today and already forgot I had that problem. But checked the voltage drop with both the hydraulic jack and the trim running at the same time. Less than a 1 volt drop!

Plus oddly it appears that the voltage is higher across the band. My digital is up a little over 14 when running at higher RPMs and my analog is also showing close to 14.

Nevertheless, Leon, (OH WHAT A RELIEF IT IS).

The next issue I will tackle will be the loss of fuel pressure when the motor sits overnight. Never had that issue until a few months ago. Once it starts it is fine for the rest of the day. Starts up perfectly after the first start of the day. Let me do some searching first before a post. Maybe I can find it myself. Thanks again guys.