Dan_the_fisher Posted February 5, 2017 Posted February 5, 2017 I was on the lake today and went to start the boat it started and quit(cold nature), then when I went to start it again nothing had any power. After a hour of trouble shooting I figured out that the fuse was blown and when I put a new fuse in you can work the trim fine, but as soon as you cut the switch on it blows the fuse. It has a straight ground on the the load side of the fuse when the switch is turned on. Anyone ever experienced this before? Fuse location shown in pic Quote
Super User iabass8 Posted February 5, 2017 Super User Posted February 5, 2017 Check your wiring on the back of your gauges for starters. Any loose ones touching the wrong post will blow your main fuse when you turn the key. I had it happen twice on my old boat. Had a couple loose ones make contact /w the back of the tach posts. Could be a short in the fuel pump or coils too. hopefully way2slow will be along to assist Quote
Super User Way2slow Posted February 6, 2017 Super User Posted February 6, 2017 A couple of problems with my help. I don't know the mercs like I do the OMC's, there are a whole bunch of 225 Mercs and there's not enough info there for me to offer much help. A year model would help, and I can't tell by that picture what's the fuse. The fist thing I would suggest is getting a schematic. Identify the fuse on the schematic and then see what all it provides power to. Then disconnect as many of those items as you can and try it again. If it doesn't blow, then start connecting one connector at the time back and trying it each time until you find the one that causes the fuse to blow. I it does blow, then you need to keep looking for points to disconnect. Connecting an ohm meter between then engine side of the fuse and ground would probably help find the source of the problem. Sometimes the ohm meter doesn't help because it may be something going through a relay. When you turn the key on, the relay energizes and then the fuse blows. Situations like that, you have to get on the other side of the relay and disconnect or take ohm readings. Quote
Dan_the_fisher Posted February 6, 2017 Author Posted February 6, 2017 13 hours ago, Way2slow said: A couple of problems with my help. I don't know the mercs like I do the OMC's, there are a whole bunch of 225 Mercs and there's not enough info there for me to offer much help. A year model would help, and I can't tell by that picture what's the fuse. The fist thing I would suggest is getting a schematic. Identify the fuse on the schematic and then see what all it provides power to. Then disconnect as many of those items as you can and try it again. If it doesn't blow, then start connecting one connector at the time back and trying it each time until you find the one that causes the fuse to blow. I it does blow, then you need to keep looking for points to disconnect. Connecting an ohm meter between then engine side of the fuse and ground would probably help find the source of the problem. Sometimes the ohm meter doesn't help because it may be something going through a relay. When you turn the key on, the relay energizes and then the fuse blows. Situations like that, you have to get on the other side of the relay and disconnect or take ohm readings. It's a 99 225 merc efi, I would love be to find a schematic of it then I would be able to find the problem fairly easily. It's not through a relay, I busted a fuse and put the stabs in so I could ohm it and I'm getting short all the time with no power applied. As for the pic of the fuse it's on the top right hand side of the box with the warning label on it, you can see the stabs of the fuse sticking out of it. Quote
Super User Way2slow Posted February 6, 2017 Super User Posted February 6, 2017 Here's a link to a 98, check it out and see if it's close enough to yours, may be identical http://files.motorka.org/plm/mercury/service_manual/mercury_2t/mercury_225_225EFI_250EFI/2a.pdf Also, check this one out. http://www.mdmotors.ru/netcat_files/216/180/MERCURY__2.4L__2.5L__3.0L_V6_EFI_Tehnicheskoe_ustroystvo_dvigateley.pdf If you know how to troubleshoot electrical, between these two, you should be able to find it. Identify the fuse and I can look at them and help you if needed. A word of caution, the first thing you need to do before poking around the ECM with an ohm meter is to unplug it. The voltage from the meter in the ohms mode is more than a lot of the 3 to 5 some of the stuff going to it and an blow an ECM. That's any ECM, cars also and do not try taking ohms reading on ECM terminals. Also, after you unplug it, check for your short, the ECM could be the cause of it. If it is, that'll ruin your day. I just realized, something is wrong. Here I'm telling a guy how to trouble shoot the electrical on his 225 EFI Merc. Another post I'm telling a guy how to rewire his TM. Another I'm telling a guy how to reload bullets. Another how to build an tack driving rifle. then how to roast and brew coffee, and on another, how to bake a cake and all about flours. ?????????? Something don't seem right here. 1 Quote
Super User OkobojiEagle Posted February 7, 2017 Super User Posted February 7, 2017 On 2/6/2017 at 2:40 PM, Way2slow said: I just realized, something is wrong. Here I'm telling a guy how to trouble shoot the electrical on his 225 EFI Merc. Another post I'm telling a guy how to rewire his TM. Another I'm telling a guy how to reload bullets. Another how to build an tack driving rifle. then how to roast and brew coffee, and on another, how to bake a cake and all about flours. ?????????? Something don't seem right here. Renaissance man... oe Quote
Super User Fishing Rhino Posted February 8, 2017 Super User Posted February 8, 2017 2 hours ago, OkobojiEagle said: Renaissance man... oe Years ago, Yankee Magazine had a man who answered all manner of questions on just about any topic. The title of his page was, "The Oracle". edit for correction. It was, Sayings of the Oracle. The Bass Resource Oracle has a nice ring to it. https://newengland.com/today/living/new-england-environment/sayings-of-the-oracle/ Quote
Super User Way2slow Posted February 8, 2017 Super User Posted February 8, 2017 I am a old fart with many talent's simply because I've always felt there was nothing I couldn't do, and not a lot of I haven't done, and I've always said "if man made it, I can fix it" but don't think those titles fits'. I think it's more from growing up a poor a** country boy that if I wanted something, I had to learn to do it myself because I never could afford to pay someone else. Now that I've gotten this post a mile off subject, I wonder if the OP has had any luck finding his short. 2 Quote
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