Electrical riddle (tilt and trim)

[Tacklebuster]

I got one I just can't seem to figure out.

Yami 150 4 stroke. Batts were pretty drained so I took one out and charged it. When that one was charged, I put it back in and took the other weak one out and put it in the charger. Now it get's interesting..... The boat I am looking at here to buy the motor lifted up and down just fine with a couple of drained batts. I decided to lift the motor up to check a few things out with just the one batt installed that was charged and the motor lifted up real slow. The insulation around the ground wires started to smoke and the wires were so hot you couldn't touch them. Took the way drained batt and hooked it up so all the batts were in place and everything hooked up and the motor lifted fine without issue. Why would taking one batt out make the ground wires so hot the insulation around them burn up but be fine when all the batts are hooked up?

[fishkisser]

The only thing I can think of is that a connection was loose ...
That would cause resistance and heat up the wiring ...
Are all your grounds tied together at a buss bar ?
Are your batteries run in paralell or switched ?
If both your negative terminals are daisy chained together...
And then run to a common buss bar it could be that the connection was loose at the #2 Battery position
Pictures Man We Need Pictures ....
Barney

[Tacklebuster]

The only thing I can think of is that a connection was loose ...
That would cause resistance and heat up the wiring ...
Are all your grounds tied together at a buss bar ?
Are your batteries run in paralell or switched ?
If both your negative terminals are daisy chained together...
And then run to a common buss bar it could be that the connection was loose at the #2 Battery position
Pictures Man We Need Pictures ....
Barney

Batt #1 was in place and the selector switch was on 1. Batt #2 was disconnected and on the charger. The cables were layed on the floor not touching anything. Motor would tilt real slow.... wires would burn.

Batt #2 was then put back in place and connected. Selector switch was still turned to 1 and all went well. I then turned the selector to 2 and all went well. It just happens when 1 batt is disconnected.

Since the insulation was burned off, does it really need replaced? It was only really covering 80 percent of the wire at best.

[fishkisser]

The only thing I can think of that makes sense is that the ground for the motor is connected directly to battery 2 ... and a partial ground for the motor is established by way of the transom or bonding strap while using battery 1
And then when you hook up battery 2 again all is well because a 100% ground is established again ...
It seems weird but there has to be a logical explanation for this ... I hope your not like Me , because this would drive me crazy until I figured it out ...
All the burned wires should be replaced , overheated copper does not carry current normally anymore and corrosion becomes a factor also ...
Barney :wave:

[chucks electric]

hello, how many wires are connected to the negative terminal post on the batteries? your only allowed 4 per connection also don't use wing nuts, use a regular hex nut and a wrench. you had a poor ground that is were the heat came from. my recommendation is to add a small ground buss and use a 4ga wire as a jumper to the buss the the buss. replace the terminal ends with uninsulated terminals crimp not solder and seal with double wall self sealing heat shrink.

[Tacklebuster]

hello, how many wires are connected to the negative terminal post on the batteries? your only allowed 4 per connection also don't use wing nuts, use a regular hex nut and a wrench. you had a poor ground that is were the heat came from. my recommendation is to add a small ground buss and use a 4ga wire as a jumper to the buss the the buss. replace the terminal ends with uninsulated terminals crimp not solder and seal with double wall self sealing heat shrink.

Both Batts have a main thick black wire and then another smaller wire in a conduit that connect to the negative posts. They did have hex nut. The smaller wires on the motor were crimped and attatxhed below either a grease zert or another bolt that went directly to the motor. Those smaller wires had some rubber insulation but they were only 80 percent (at most) covering the wire and you could slide the insulation back and fourth.

Barney,
I think you are right. I think somehow the motor is grounded to the second battery somehow. Even thought the batt was dead, it needed the wires hooked to it for it to work with batt #1 or the smaller ground wires on the motor would get hot. Makes no sense to me and it is driving me crazy.

Thanks for all the help guys:flowered:

[Highmark]

Question. When you removed the wires from the battery, Was there any
salts on the termenial fitting.. If so you may just need to clean the post
connectors and the battery posts and make sure you torque the attachment bolts. Here is why. if you are getting hot wires. most likely
there is a loose connection creating a high resistance in the current flow
that is why it got hot. find the restiction and fix it and your problems are
gone.

HM

[fishkisser]

Barney,
I think you are right. I think somehow the motor is grounded to the second battery somehow. Even thought the batt was dead, it needed the wires hooked to it for it to work with batt #1 or the smaller ground wires on the motor would get hot. Makes no sense to me and it is driving me crazy.

Thanks for all the help guys:flowered:

Makes sense if #1 is the house battery and #2 is the starting battery ...
A pretty common setup , you can solve the problem by bringing both negative cables from the batteries to a common buss... And then hook up your motor grounds to this same buss ... A bluesea #2106 is the one I just installed on my 2 motors 2 selector switch setup on my sled ...
Good luck ... Barney:wave:

[Green Machine]

I got one I just can't seem to figure out.

Yami 150 4 stroke. Batts were pretty drained so I took one out and charged it. When that one was charged, I put it back in and took the other weak one out and put it in the charger. Now it get's interesting..... The boat I am looking at here to buy the motor lifted up and down just fine with a couple of drained batts. I decided to lift the motor up to check a few things out with just the one batt installed that was charged and the motor lifted up real slow. The insulation around the ground wires started to smoke and the wires were so hot you couldn't touch them. Took the way drained batt and hooked it up so all the batts were in place and everything hooked up and the motor lifted fine without issue. Why would taking one batt out make the ground wires so hot the insulation around them burn up but be fine when all the batts are hooked up?

The boat I am looking at here to buy? Are you looking for another boat and did you sell your Seahawk?

I am no electrician by any means, but would you have the same problem with two new batteries? Seems like a partial load would put more heat to the wiring than a full load?

Green Machine