releget Posted August 21, 2017 Posted August 21, 2017 When my trolling motor died and I was troubleshooting why, I tested the plug with a multimeter and it read 34.5v's. This is strange because I only have a 24v system. My first thought was the previous owner may have tied in the cranking battery. I completely unhooked the cranking battery and for some weird reason other then today is a solar eclipse I still was reading almost 36v at my TM plug. How is this possible? I admit I am not great on this subject so I asked to make sure I was using the multimeter right and I was. And no there isn't a 3rd battery I'm unaware of or it's invisible So any help would be greatly appreciated. Quote
Super User J Francho Posted August 21, 2017 Super User Posted August 21, 2017 Do you have a pic of the battery wiring? If you have a 24v system, then you should have three batteries: two deep cycle, and one cranking. Quote
releget Posted August 21, 2017 Author Posted August 21, 2017 1 minute ago, J Francho said: Do you have a pic of the battery wiring? If you have a 24v system, then you should have three batteries: two deep cycle, and one cranking. Correct. 1 crank and 2 deep cycle. Tried posting but said file was too big. I'll try again. Quote
Super User J Francho Posted August 21, 2017 Super User Posted August 21, 2017 https://postimages.org/ 1 Quote
releget Posted August 21, 2017 Author Posted August 21, 2017 9 minutes ago, J Francho said: https://postimages.org/ https://postimg.org/gallery/po11ep5c/ thank you 1 Quote
Super User J Francho Posted August 21, 2017 Super User Posted August 21, 2017 Hmmm. Can you disconnect all the 3-bank charger wires, and take a reading? I wonder if that's where it got screwed up. Quote
eddallen Posted August 21, 2017 Posted August 21, 2017 The straight up answer is you CAN NOT get 36 volts from two 12v batteries. Did you disconnect both cables from the crank battery? If so, try un-plugging the battery charger and see what it reads. 2 Quote
releget Posted August 21, 2017 Author Posted August 21, 2017 4 minutes ago, J Francho said: Hmmm. Can you disconnect all the 3-bank charger wires, and take a reading? I wonder if that's where it got screwed up. It's only a 2 bank charger Quote
Super User J Francho Posted August 21, 2017 Super User Posted August 21, 2017 2 minutes ago, eddallen said: The straight up answer is you CAN NOT get 36 volts from two 12v batteries. Exactly. This is weird. I don't really know what's going on here. 1 Quote
releget Posted August 21, 2017 Author Posted August 21, 2017 7 minutes ago, eddallen said: The straight up answer is you CAN NOT get 36 volts from two 12v batteries. Did you disconnect both cables from the crank battery? If so, try in-plugging the battery charger and see what it reads. I did completely unplug cranking battery and made sure it wasn't touching either post. Did you mean unplug the charger? If so I didn't have charger connected during test. Quote
eddallen Posted August 21, 2017 Posted August 21, 2017 1 minute ago, releget said: I did completely unplug cranking battery and made sure it was touching either post. OK sometimes if the charger is ON, when you disconnect one of two batteries the charging channel for that battery can remain open (supplying voltage). If you unplug the charger it will close that channel. Which two batteries is the 2-bank charger feeding? What all is on your boat? Might there be a house battery for your electronics? 1 Quote
releget Posted August 21, 2017 Author Posted August 21, 2017 Here is a labeled picture of what is on the 2 deep cells https://s3.postimg.org/oka5zswer/IMG_7693.jpg 2 minutes ago, eddallen said: OK sometimes if the charger is ON, when you disconnect one of two batteries the charging channel for that battery can remain open (supplying voltage). If you unplug the charger it will close that channel. Which two batteries is the 2-bank charger feeding? What all is on your boat? Might there be a house battery for your electronics? If there is it's very well hidden. The 2 bank is charging the 2 deep cells. I have a 2004 Nitro nx882 with 3 electronic units, motorguide TM, an annoying anchor buddy, couple lights, normal dash etc. Quote
eddallen Posted August 21, 2017 Posted August 21, 2017 Haha before you tear the boat apart looking for a battery, remove the pos from both deep cycle bats and the crank bat, then see if electronics will turn ON. 1 Quote
Super User Further North Posted August 21, 2017 Super User Posted August 21, 2017 4 hours ago, J Francho said: https://postimages.org/ Thanks for that - I've been looking for somthng since Photobucket piddled all over their customers and their own bed... 1 Quote
releget Posted August 22, 2017 Author Posted August 22, 2017 Why is it always the most simplest thing. I decided to start from the beginning and unhook everything to the bats and test them 1 by one. When I put my multimeter on it read 18-20v. Now I know something is wrong with my multimeter. Go buy another one. Also reads 18-20. Frustrated as hell I search car forums for odd multimeter readings and found out it was as simple as the 9v battery in he multimeter is dead enough to cause miss readings. I used the same battery in both multimeters so when I purchased a new battery and checked. Perfect. Hooked it all up and had my 24v at plug. So this was all due to a miss read and dead 9v battery. Why do I always learn the hard way. I really appreciate you guys working though this with me but consider this case closed. 5 Quote
eddallen Posted August 22, 2017 Posted August 22, 2017 10 hours ago, releget said: Why is it always the most simplest thing. I decided to start from the beginning and unhook everything to the bats and test them 1 by one. When I put my multimeter on it read 18-20v. Now I know something is wrong with my multimeter. Go buy another one. Also reads 18-20. Frustrated as hell I search car forums for odd multimeter readings and found out it was as simple as the 9v battery in he multimeter is dead enough to cause miss readings. I used the same battery in both multimeters so when I purchased a new battery and checked. Perfect. Hooked it all up and had my 24v at plug. So this was all due to a miss read and dead 9v battery. Why do I always learn the hard way. I really appreciate you guys working though this with me but consider this case closed. We ALL continually learn, if our minds are open to the task. Glad all is well. 1 Quote
Super User J Francho Posted August 23, 2017 Super User Posted August 23, 2017 Man, I'm glad you figured it out! Quote
Tim Kelly Posted August 23, 2017 Posted August 23, 2017 Well I think we've all learnt something there. Thanks for finishing the story. Quote
Super User Further North Posted August 23, 2017 Super User Posted August 23, 2017 On 8/22/2017 at 8:28 AM, releget said: Why is it always the most simplest thing. I decided to start from the beginning and unhook everything to the bats and test them 1 by one. When I put my multimeter on it read 18-20v. Now I know something is wrong with my multimeter. Go buy another one. Also reads 18-20. Frustrated as hell I search car forums for odd multimeter readings and found out it was as simple as the 9v battery in he multimeter is dead enough to cause miss readings. I used the same battery in both multimeters so when I purchased a new battery and checked. Perfect. Hooked it all up and had my 24v at plug. So this was all due to a miss read and dead 9v battery. Why do I always learn the hard way. I really appreciate you guys working though this with me but consider this case closed. OK, I'm gonna put that one in the memory banks...never woulda thought about that. Quote
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