battery power cutting off while going down road

chevy chassis

ok.my first problem was that i discovered my ground wire to the starting battery was loose and i twisted it to get ready to tighten it up.the terminal end broke in half in my hand.at that point i grabbed hold of the positive cable to check it and it was very hot.i guess that is because i ran for a while with a bad ground connection!so,i replaced both terminal ends and checked voltage on both batteries...house and starting and both were good...12.2 and 12.4....coach will start and run now but every once in a while,service engine light will flash once and acts like transmission slips and coach acts like it loses power.drove coach the previous day about a 30 minute trip and had none of these issues...any ideas on what might be causing my problems?

"motor home dying while going down the road "

Is the charging system sitting at a bar, somewhere tossing down a few when this is going on?

You have an intermittent fault at a MAJOR harness junction point OR a low battery plus an intermittently operating alternator (not likely).

Start tracing the positive AND negative battery chassis cables right from the chassis battery. There is a major junction somewhere and it may even be the primary feeder to the vehicle under-dash fuse block.

The intermittent connection junction is passing a lot of current so the bad connection should show signs of major arcing and overheating.

Don't forget the chassis negative ground wiring.

You can proof this point by running a new BRIDGING wire directly from the alternator output stud to battery positive.

A bad connection that cuts power to the ignition - alternator CONTROL circuit would leave the battery dead as a doornail and when you disconnect the jumper battery the engine would die. Not the cause unless you mis stated the symptoms in your post.

johnandbren wrote:
1992 monterrey by cobra class a motorhome

NEED CHASSIS INFO!!!! Ford? Chevy? Freightliner? John Deere?
Not Workhorse as they were not building in 1992. Doug

Get a multimeter, and with engine running check the voltage at both sides of the charge control isolator relay, sometimes called a, bird..bidirectional relay
Both sides a :) a big terminals should be 13~14v with engine running
You might have a solid state aka Diode based battery isolator center post comes from alternator, left side and right side goto chassis battery and house batteries

My cable leading to the starter had the insulation burned off by the headers. Sometimes going down the road or on a hill or taking off from a stop the engine would die. I discovered the insulation problem when I wiggled the cable to see if it was loose. The cable shorted against the frame, bunch of sparks. As the engine would move due to torque the cable would short against the frame causing the engine to die.

Bad battery, and the alternator is keeping it going after you jump it.

The dead battery will hurt the alternator after time, and jumping it (almost) every time will be annoying.

You do need to provide more information, as much as possible, to get a better answer! (as mentioned above)

Whose Chassis is this Class A riding on? The main power feed to the chassis (engine) part is done quite differently on the two.

Easy Steps:
Have the battery load tested at any auto store.
Buy a voltmeter and check that it's being charged.
Remove and clean terminals.

Take pictures first.

It is quite possible that you have a bad solenoid. Usually found on engine compartment firewall.