Isolator

[FW]

Hi; If a battery isolator (solenoid type) fails, can this cause melted insolation
on battery cables?

Thanks

[palehorse89]

Hello , I would say no to your question, when melting occurs in 12 DC it is due to bad connections or a wire that is not sized and fused right for the load it has on it. I have always been to by old timers that another way to explain DC voltage is DC = Destructive current. Check all your connections where this is happening and make sure there is a good connection.

[bruceisla]

Originally Posted by FW

Hi; If a battery isolator (solenoid type) fails, can this cause melted insolation
on battery cables?

Thanks

Not impossible but very unusual. Can you describe the location of the melting and/or provide pictures?

The only example of a failed/failing isolator relay causing cable insulation damage (that I can think of) would be if the chassis battery was low, you used the boost switch, cranked the engine for "awhile" and the contacts inside the isolator were badly corroded.

Insulation failure is caused by a high resistance to current flow and the melting usually occurs at the point of highest resistance ... for instance, close to a lug that is either loose or corroded.

[Old Bounder]

Originally Posted by FW

Hi; If a battery isolator (solenoid type) fails, can this cause melted insolation
on battery cables?Thanks

If the melting insulation is right at the cable connections to the isolator solenoid, then 'YES' the internal solenoid contacts are probably corroded and and causing a heating problem. If the melting is at another location, then look for a loose and/or high resistance connection nearby. The resistance can also be in the cable, where it is crimped to the terminal connector, as well as the bolted connection.

[FW]

Hi; I'll try to post a picture. Never tried this before.
I guess you have to check in galleries for picture.

[Dr4Film]

Nope, no gallery needed. Use your own photo that has been reduced in pixel size to meet the upload requirements.

Then when posting use the "Manage Attachments" feature located below the message box under Additional Options

Dr4Film ----- Richard

[FW]

Hi; Maybe like this?
Well thank you!

[MSHappyCampers]

WOW! That's scary!

[YC1]

Holy smokes batman! Darn near burned the outhouse down.

The lower red cable looks like it goes behind the solenoid. If that rubbed through and shorted to the cabinet it could have done that.

In 40 years of installing thousands (in my business) of solenoids, I have never seen one short to the housing. There is always a first.

I do not believe it is due to a bad or weak connection. Cables of that size take a tremendous amount of current to melt.

I also believe you may have had a tiny fire that went out. Looks like split wrap insulation melted away.

A few more pictures would help diagnose.

[Old Bounder]

I'm with YC1, that's some serious melting. I'm guessing that the solenoid was not involved at all unless someone reversed one of the attached battery banks. It would take a direct short to ground to produce that mess..

[YC1]

Originally Posted by loulong

I'm with YC1, that's some serious melting. I'm guessing that the solenoid was not involved at all unless someone reversed one of the attached battery banks. It would take a direct short to ground to produce that mess..

With the picture my guess is the wire that goes behind the solenoid shorted and the solenoid was engaged at the time. Hence, current flowed through both cables towards the short. One through the solenoid and the other directly to the short.

[Jimooo]

Obvious over current wires got real hot and made a small fire which spread to adjoining wires , maybe the solenoid is not the cause.

Good Luck,

James

[TQ60]

With a phone screen it looks more like fire than hot wire melt.

Hot wires ooze or get dark, flowing black crispy looks like fire damage.

May have been arcing and or heat to get plastic wet melted, at this point it can ignight, that stuff looks good but is risky and falls apart over time.

You likely had a bad splice, connection or something with high resistance, this caused the plastics to melt, then catch fire.

You were lucky.

Tear it down and look for the source.

Then repair properly, good fuses and properly rated materials

[FW]

Hi; Originally the wiring had black and ground rubbing together. After
4 years and rough roads insulation rubbed through. Solenoid checked
OK, and with new, rerouted wiring, I feel confident all is again right with
the home.

Thanks