I documented my starter issue this past week in another thread. Thanks again for everyone's help.
I also posted a picture of an insulation failure on the starter positive cable that I found while trouble shooting what turned out to be a failed terminal on the starter solenoid. I'm attaching the picture again. On my coach, the cable was routed in a loop up and over to the top of the starter. In doing so, it was centered in the 5" to 6" of space between exhaust manifold and the turbine exhaust. So it was constantly getting blasted by heat from two sides. It is fairly easy to see from the top side of the engine and I first saw it from the bottom, so it can be seen from there but it is harder to get in position to see.
I strongly recommend all 400 ISL owners check for the same insulation failure.
On my new starter, I was able to route the new cable out the side and down so that it only has to deal with the turbine exhaust pipe and not the manifold.
Hope this helps someone avoid a similar problem,
Rich
Very interesting read, Rich. I had an intermittent starting problem for a couple of months that I could not diagnose. Then one morning while on the road I turned the key and got nothing. One last try after a prayer and the ISL 400 fired up. Went directly to a Kenworth Service Center explaining the emergency and that I could not shut down. They squeezed me in an I had a worn 12V wire to the solenoid with a dead short to the metal case that melted just about everything around it. It had been chaffing against the case for years. New Delco-Remy and off we went. That whole assembly seems to be a vulnerable area. Tight bends and lots of heat. At that time I also rerouted my big cable away from the exhaust. I agree with you that owners might be well served checking those wires...heat shielding and chafe guarding as necessary. I thought my issue was a one off.
Thanks for information guys. I will be checking mine before dragging out again...
When new starter cables are installed, you might look into the possibility of adding additional heat protection to the cables. There are many products available in the HotRod industry to protect wiring and fuel lines from engine heat. They make tubular sheathing out of heat resistant woven material that slips over or wraps around the wire or fuel line. Anything that provides some extra insulation from heat sources would help. Some examples of this type product shown on page linked below:
Automotive Hose & Fuel Line Insulation | Shop Hose Heat Shield & Fuel Line... (https://www.jegs.com/c/Fittings-Hose_Hose-Line-Protection/201707/10002/-1)
Chuck,
Thanks for the link.
The negative cable should be fine and I've routed the positive as far from the heat as I can. At least now, it is farther away and only getting heat from one side, not two. I'll pursue the cable wrap when I get home next month.
Rich
The fire sleeve is great stuff. In the eighties i was involved with twin engine Cessnas and during engine changes all the lines would get trashed the fire sleeve always looked brand new. Wish i had kept some. Now I'm buying it. Again great stuff
This looks interesting. It doesn't seem to say anything about battery cables but there is no reason to think it wouldn't work. I would use a 1" size.
Any battery cables, particularly positive ones, should have abrasion protection anywhere rubbing is possible.
Perhaps a different type of lug would help with the cable routing. Added to my list to check out next time I am under the coach.