ISC 330 starter keeps runing

I sure hope you keep us up to date on how this turns out.
Not good, I fear.

First, Thanks to all for your assistance. Second, I found the solenoid. It doesn't look like a standard round type solenoid. See White Rodgers 120-105851. It is located behind the large black plastic box in the aft passenger bay, above the inverter. it is housed on a plate that also holds high amperage fuses and relays for grid heat. THX TB

TANDDANDBIGE wrote:
It resides behind a black plastic cover in the aft passenger bay above the invertor along with high amperage fuses and relays for the heat grid. White Rodgers 120-105851 THX TB

I think NOT.

That might be a "battery" solenoid but certainly NOT a starter solenoid. The starter solenoid is a part of the truck chassis and should NEVER be mounted inside the "house" part. Never.

The starter draws huge amounts of current.....and needs to be as close to the chassis battery and the starter as possible.

First, thanks to all for your help and support. Second, I found it. It doesn't look like a standard round solenoid, thus I didn't recognize it. It resides behind a black plastic cover in the aft passenger bay above the invertor along with high amperage fuses and relays for the heat grid. White Rodgers 120-105851 THX TB

OK, gotta ask:
If you can not FIND the solenoid, how do you know for sure that the other end of the wire you are disconnecting actually GOES there ??

Have you found the starter yet ? The fat usually red wire feeding the starter should go to the solenoid.

This might help for maybe a picture,

https://www.google.com/search?q=diesel+starter+relay&tbm=isch&source=iu&ictx=1&fir=FCBrb2yx3tTMKM%253A%252C87wm1kg1e1nnBM%252C_&usg=__flE1habH9y1chabUw_sct_6bzws%3D&sa=X&ved=0ahUKEwjphO2hyqbaAhXE2VMKHTJnBh4Q9QEIQzAA#imgrc=FCBrb2yx3tTMKM:

Verification complete. It IS the start solenoid/relay. My problem now is to find it. With the starter solenoid wire removed, it stays hot after turning key to start for about 15+ seconds until I hear a "click" and voltage goes to zero. I just cannot find the source of the click I have listened/looked high and low but no luck. Does anybody know where Holiday Rambler and/or Cummins would hide this thing and what it looks like? Any assistance would be greatly appreciated. THX TB

Passin Thru wrote:
Starter drive is worn out.

Could be.

But going to all of that trouble without FIRST checking the other possible causes would NOT be a wise thing to do.
Could be a LOT of time and money wasted.

Typically the starter solenoid is located on or near to the starter itself.

If there is another relay between the ignition switch and the solenoid, it could be most anywhere.

You need to VERIFY whether this is a starter relay that is continuing to supply power or whether you have a mechanical issue with the starter.

Either will cause the same symptoms.

I would start by doing a check on the electrical supply side (whether the starter relay is continuing to supply power to the starter after key is not in start position).

Starter drive is worn out. Pull starter, go to a starter shop and have it rebuilt. Fix it now for a smooth summer.
This guy is in central Wa.
http://soundstarterandalternator.com/