Side-Power Bow Thruster Troubleshooting and Maintence

I've been having some issues with my Side-Power SP75 bow thruster lately. I had trouble finding helpful information on the website or in the manual so I called IMTRA and discussed what was going on. The tech sent me some really good guides for maintenance and troubleshooting. I've attached three PDF's here to share with the group.

Tom
IP 420-35
La Vida Dulce

Here's one more. This was a list of suggestions sent to me by the tech at IMTRA.

Do This First – Troubleshooting Tips for the Side-Power Bow Thruster:

• Check the operating voltage on the batteries, it should be 1 to 1.5V higher than at the thruster, a larger voltage drop then 1.5V should be looked into.

• Check the rated CCA of the batteries, at the rated 1045 CCA at zero degrees Fahrenheit, operating volts at the batteries should be in around 11 – 11.5V.


• Remove the motor from the boat and blow it out with compressed air (use respiratory protection).

• Check to make sure none of the brushes are sticking.


• Remove the prop and bring it to the surface for complete cleaning and anti-foul painting.


Tom
IP 420-35
La Vida Dulce

Thanks for the information, will do this soon.

Wow, this last guide really helped out. Spent a good part of the day opening things up and found the main fuse for the thruster had gone. Trip to West Marine and got lucky to find the large fuse. Smiled, replaced it thinking all was good. Still no operation.

Original owners manual is really fuzzy on the parts/connections on the motor, and the current location of the unit in the bowels of the boat makes it no easier. Went through the steps identified here and found the solenoids bad.

my voltage at the batteries drops from 12.7 to 11.2 when running the thruster, is that too much ? do I need new batteries ?

Did you leave the motor installed when you checked the brushes? I would think you could remove them and just cove below then with cloth. Is that possible? Thanks! guy

I have checked the brushes with the motor in place but it's worth taking the extra time to pull the motor to blow out the carbon dust.

Tom

Capjules....I think that voltage is still within the safe range. The thruster motor is a huge draw on the batteries and that is one reason you want to make short bursts during operation. It's also why you want to have the engine running at the same time. As long as your battery voltage goes back up you're probably OK.
Tom

anyone know how much oil the SP75T takes ?

Thanks.

We took a test sail of an Island Packet 420 last week that we are considering purchase of. Upon manouvering onto a mooring, the guy at the helm said the bow thruster cut out after he had it pressed on for 10 seconds or more.. Left to recover, it came back and worked again, but something we need to look at when we go ahead. It runs off it's own battery, so is it because it needs a little lighter treatment? i.e. bursts of a couple of seconds? Have looked at the troubleshooting guides helpfully posted and couldn't see anything obvious apart from maybe needs a clean/service/oil etc. Where is the motor located in the IP 420? Is it easy to get to? 

The earlier advice from Tom of IP 420-35 is excellent as well as the PDFs from IMTRA. Download them and keep them available on the boat.

Let's start with simple solutions first. If this boat has been in the water for awhile with little use it is likely that the thruster props and the tunnel are covered with barnacles. This will vastly reduce thruster performance, cause the current draw to rise, and potentially kick the breaker or thermal cutoff on the motor itself. The thruster needs at least annual maintenance out of the water where the two zincs, then the props are removed, the tunnel and props scrapped clean including the metal gear/shaft area for the props, and then all coated with bottom paint. Carefully tape off the metal shaft and area where the props seat so they do not get painted. Similarly, tape off the center area of the props before painting. After 5 winter months in the lower Chesapeake my thruster is barely useful, but then I am motoring a few miles to haulout. 

I would also do a complete drawing and inspection of how this Side Power is installed. It is under a front bunk where you will find the motor and tunnel, local batteries to help it, a circuit breaker and fuse. You want to note the exact wiring, wire sizes and battery type, switches, breaker, fuse and so forth on your drawing. Depending on model you will also find a reservoir of gear oil with hose. The gear oil should look clear and up to level. You should check all connections - clean and tight. Be careful to not over tighten the battery connections they strip easily. Finally you should see how the front batteries are charged, note their present no load voltage and find hepefully that they connect back to your main house bank with likely a 2/0 cable. These front batteries are likely used to power your windlass as well since thrusters and windlass are not often used together. I will stop here. fyi - Side Power on our boat for 16 years, no problems so far and same for several friends. Have helped folks pull the motor and clear some stuck brushes.

If you reach out to me by sending a private message via this site I will reply with a phone number/email should you continue to consider my help. You could as well post your email address and I will reply to you. I have helped a number of others avoid throwing expensive parts at this and often still not resolve things.

Thanks for this and sorry it took so long to reply (we've been buying a boat )

We located the oil reservoir for the bow thruster in the locker behind the forward shower and it was completely out of oil, so the first thing we have done is top that up. We will do an oil change on next haul out.

When it was hauled out for survey a couple of weeks ago, there wasn't a lot of growth on it, but gave it a bottom wash and scraped off any barnacles. Since taking ownership of the boat, we have only used the bow thruster a couple of times, and it hasn't cut out on us - but we have been using it on short blasts.

We will check out the battery config etc next time we are up there. I know they have different switches.

I would be suspicious of finding no lube oil. In 15+ years I have never seen the reservoir down at all. Watch this one for awhile. To drain the unit with the boat out of the water, there is a removeable plug (hex fitting) at the bottom of the gearleg and you can fit a small catch pan under it. I never fully drain the reservoir, just enough to get the out old stuff and then top off.

You have a great boat - enjoy!!