2010 Speedster 150 255 Electronics overheating

[skeet88]

This has now happened to me twice, both time while pulling a tube at a low speed of about 20 mph. The boat suddenly completely died. The digital display went blank and the engine would not crank. No beeps or warnings or error codes. The bilge pump and blower still worked, so there was electrical power. After about 10 minutes sitting dead in the water, when I attached the lanyard to the start key, the display would come up normally, but then go blank again after about 3s, then doing this again in another couple of minutes the display would come up and go blank after 10s. This repeated, the display coming up for a longer period each time until after about ½ hour the displayed stayed on, the engine started and the boat ran fine back to the launch ramp.

Seems some electronic component is over-heating and then self-heating beyond some temperature limit until it is finally cool enough. The shop manual does not have a wiring diagram (Would like to find one?), but it seems to me that there are really only three electronic components on the boat, the digital display, the voltage rectifier, and the engine ECU. I replaced the voltage rectifier after the first event, but that was not the problem. Seems like the only other thing it could be is the engine ECU. The engine bay was very hot. The boat will cruise at 40-50 mph without a problem; pulling the tube seems to cause the over-heating of something. Does the ECU have over-heating protection causing it to turn off? Any other ideas of why this is happening and how to prevent/fix it?

 

[Joe Starbuck]

Hmmmm, I see why you think it is temperature dependent, because it slowly gets better. However, I would ask myself, "what parts can cause those symptoms?" Can the EPCM shut off the digital display? I don't know for sure, but I would have guessed not. Can the voltage regulator? It could fry it, but don't think it could shut it off, and it can't stop the engines. I have heard of digital displays shutting off, with the engines still running, so not sure the display is the likely root cause.

Things that can cause these symptoms include: safety lanyard circuit, battery switch (maybe, on my boat the bilge auto circuit goes around the battery switch, but the bilge blower and bilge manual do not).
Sorry, I don't have experience with this specific problem, but sometimes widening your field of investigation can be helpful.

The tubing situation is inciteful (as long as it is not a coincidence). You noticed the engine compartment was way hot when tubing, but I wonder why it would not be equally hot when running 40-50 mph (similar power output, and power should equal heat). Perhaps the breeze at 40-50 is enough to keep the bay cool.
I know you want an answer without risking a recurrence, but if you go tubing again, try running the blower while tubing, I know that keeps the engine bay a lot cooler (for troubleshooting, not as a solution).

 

[skeet88]

Thanks for those suggestions. I'll look into some of that. Yeah, I'm not sure if the ECM can shut off the digital display; that is one of my questions. Running with the blower to cool the engine bay is a good idea; I'll try that. I know the engine starts and runs with the display unplugged, so I know the display is not the problem.

I'm thinking that at the lower speed, the convective heat transfer rate from both the hull and the radiator will be lower than at high speed, so that may be a contributing factor to higher temperatures in the engine compartment.

Thanks again!

 

[Joe Starbuck]

Thanks for those suggestions. I'll look into some of that. Yeah, I'm not sure if the ECM can shut off the digital display; that is one of my questions. Running with the blower to cool the engine bay is a good idea; I'll try that. I know the engine starts and runs with the display unplugged, so I know the display is not the problem.

I'm thinking that at the lower speed, the convective heat transfer rate from both the hull and the radiator will be lower than at high speed, so that may be a contributing factor to higher temperatures in the engine compartment.

Thanks again!

Convective heat transfer, now you are speaking my language! I suspect that delta temp between the engine water (190 deg. F. ??) and the lake water (70 deg. F. ??) is roughly identical when traveling 15 mph and 45 mph. At zero mph I might entertain some increase in the lake water temperature right around the radiator plate.

Inspect your wiring around the battery and battery switch closely for corrosion. These high-current circuits can exhibit heating and temperature-dependent problems when corrosion gets in the joints.

 

[skeet88]

Thanks Joe! I'll look at the wiring. Next time out I'll take a volt meter with me to check if there is a drop in voltage in the wiring harness if this happens again.

Yeah, the boat speed won't affect the delta temp, but the convective heat transfer coefficient (h) between the lake water and hull will be higher at higher speeds, but I'm not sure how significant that is. I also attached a finned heat exchanger to the engine ECU; that might help if the ECU is the problem.

 

[Joe Starbuck]

Thanks Joe! I'll look at the wiring. Next time out I'll take a volt meter with me to check if there is a drop in voltage in the wiring harness if this happens again.

Yeah, the boat speed won't affect the delta temp, but the convective heat transfer coefficient (h) between the lake water and hull will be higher at higher speeds, but I'm not sure how significant that is. I also attached a finned heat exchanger to the engine ECU; that might help if the ECU is the problem.

The thick fiberglass hull is an excellent insulator at any speed. Good idea to put fins on the ECU.

 

[skeet88]

Yeah, you are probably right that there is not much heat transfer through the hull.

Thanks!

 

[pretex]

If you suspect the ECU is the problem with shutting down due to excessive heat, bring a can of circuit freeze. We used to use it in the old days to troubleshoot intermittent transistor and IC's when we suspected thermal issues. Lightly spray the ECU fins and see if comes back to life. What doesn't make sense, you say it died, no display, doesn't crank, but bilge a blower work. It's almost acts like the lanyard for the DESS was pulled out. The DESS goes to the ECU as well as the main relay in the fuse block. When you turn on the key with the DESS attached, it wakes up the ECU and Display. Those relays are known to go bad and are easy and cheap to swap out. Worth a shot.

 

[skeet88]

Thanks, some great ideas. I was thinking about putting some ice on the ECU, but the freeze spray is probably safer and more convenient.

The lanyard for the DESS was definitely not pulled out except that I pulled it out between each try to get the display to function again.

I had not thought about relays, but those are active components that might be susceptible to overheating and self heating. I should check how many and where they are. I guess I could try the freeze spray on those as well and perhaps check the downstream voltages.

Thanks much!

 

[pretex]

I checked the wiring diagram on yours and you only have the one in the fuse block that I am talking about. It is a little plug in black one, just like an automotive relay. You can tap on it too and if it flakes out, otherwise the coil might be marginal when it gets hot it de-energizes.

 

[skeet88]

That's a big help. I may just change out that relay.

Thanks!

 

[pretex]

You only have 3 relays in the boat, main relay that I am taking about, a gauge backlight relay, and the starter relay. See below which shows the wiring of the DESS and Main relay.

 

[skeet88]

Great, I got it. The wiring diagram is extremely helpful. I was not able to find that online.

Thanks again!

 

[DooGuy]

If it’s happening with tubing, ie lots of sharp turns etc, my thoughts are something’s loose, bad ground or loose battery cables, maybe at back of the on/off switch etc. always like to start with easy stuff before diving deeper etc. heat can generate quickly with loose cables.

 

[skeet88]

Always a good idea to check the easy stuff. A possibility, but I doubt it. The tubing was pretty much in a straight line, not too much turning. Did a lot more sharp turns while not tubing, however.

Thanks.

 

[POPPS]

Check all your connections,,,especially at the battery,,,connections at the battery,,,fuse holders,,,and grounds to the motor,,,a bad connection when the motor is warm will trip the ecu,..test the lanyard,,,could be that,,,and test out the dess post,,,lanyards are more prone to failing...

 

[skeet88]

Good idea. I'm going to figure out what some good test points are and keep my DMM with me.

Thanks!

 

[MacSeaDoo]

I would start with your DESS post. If the magnetic Reed switch does not operate, you will have no power to anything as described.

 

[skeet88]

Thanks, that's another thing to consider. I suspect it is something in the engine bay, however, because that is where it is really hot. I ordered a new main relay and I attached a heat sink to the engine ECU. We'll see if that solves the problem (yes, I know the blower should be pulling the fumes off the bottom of the engine bay, but think it will be fine this way if I run it long enough before starting the engine).

 

[cirrhosis]

This has now happened to me twice, both time while pulling a tube at a low speed of about 20 mph. The boat suddenly completely died. The digital display went blank and the engine would not crank. No beeps or warnings or error codes. The bilge pump and blower still worked, so there was electrical power. After about 10 minutes sitting dead in the water, when I attached the lanyard to the start key, the display would come up normally, but then go blank again after about 3s, then doing this again in another couple of minutes the display would come up and go blank after 10s. This repeated, the display coming up for a longer period each time until after about ½ hour the displayed stayed on, the engine started and the boat ran fine back to the launch ramp.

Seems some electronic component is over-heating and then self-heating beyond some temperature limit until it is finally cool enough. The shop manual does not have a wiring diagram (Would like to find one?), but it seems to me that there are really only three electronic components on the boat, the digital display, the voltage rectifier, and the engine ECU. I replaced the voltage rectifier after the first event, but that was not the problem. Seems like the only other thing it could be is the engine ECU. The engine bay was very hot. The boat will cruise at 40-50 mph without a problem; pulling the tube seems to cause the over-heating of something. Does the ECU have over-heating protection causing it to turn off? Any other ideas of why this is happening and how to prevent/fix it?

Did you notice any cavitation/vibration?
I just had a automatic shutdown when I noticed a rapid temperature rise on my dash and “sensor” warning when putting the dess back on . Floated for 10 min and eventually made it back to ramp. Had a very small stick stuck behind the impeller that likely messed up the Venturi intake for cooling.
Removed—-> all aok again.

 

[Joe Starbuck]

Thanks, that's another thing to consider. I suspect it is something in the engine bay, however, because that is where it is really hot. I ordered a new main relay and I attached a heat sink to the engine ECU. We'll see if that solves the problem (yes, I know the blower should be pulling the fumes off the bottom of the engine bay, but think it will be fine this way if I run it long enough before starting the engine).

You will have the coolest ECU on the lake.

 

[skeet88]

Did you notice any cavitation/vibration?
I just had a automatic shutdown when I noticed a rapid temperature rise on my dash and “sensor” warning when putting the dess back on . Floated for 10 min and eventually made it back to ramp. Had a very small stick stuck behind the impeller that likely messed up the Venturi intake for cooling.
Removed—-> all aok again.

No, no cavitation or vibration evident, and no warnings. In fact, at the moment it died we were idling, picking up the tuber.