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MrMark52 · 09-22-2021, 04:20 AM

Coming home from a 4 day weekend adventure about 40 miles away, with about 16 miles left to go, I started smelling a faint electrical/insulation burning odor coming from the dash of the coach.
As I had passed my last opportunity to exit for the next 2 miles, I kept the coach at 60 thinking if I don’t see smoke or flames, and the engine keeps running good, I should be OK to the next exit, or maybe even home.
Smell got a little worse, never saw any smoke. But with 1/4 mile to go to get to an exit, the “Check Gauges” light comes on. Temp gauge hadn’t moved from where it is normally (although that’s not a reliable indicator).
Didn’t have a ScanGauge or OBDII scanner hooked up. Dash A/C running on Max and cooling good.

Engine dies somewhere on the downward sloping off ramp. I get to the Stop sign and hope to restart and make the corner - it starts and runs for about 2 seconds. Try again, nothing. Dash is lit up, Fuel Gauge is pegged to the right at about the 2:00 position. Try to restart, nothing but a solenoid in the BCC on the firewall thumping.

Still no smoke, no fire. I get out of the coach, walk around to the hood, no indication of smoke. No signs of burned wiring. No “snap, crackle, pop” or groaning of an overheated engine.

Plugged in my OBD scanner, won’t communicate with the computer.

Pulled doghouse cover, nothing obvious wrong. Nothing burned, no heavy smell of burned “something” under the doghouse. Radiated heat about normal for a 95ish degree day in North Texas.

9 hours later after a 14 mile tow to the wife’s brothers house, we head the 7 miles to our home.

Spent today trying to figure it out -

Snooped around all the wire looms best I could looking for burned wires - none.

Checked all heavy cable battery and ground connections - all tight and secure. None corroded.

Checked battery voltage to starter, to both chassis ground and starter case ground - good.

House batteries are good because I can start the genset - have attempted using the Emergency Start switch while trying to start engine - no change in engine start

Using the WorkHorse electrical diagrams, I’ve checked the 40 amp fuse 49 in fuse panel - it’s good.

Swapped the starter relay with one of the other like relays in the firewall fuse panel - no change. Noted relay leads on all three like relays had plating wear. Tested the one relay that was installed as the Starter Relay - it was good.

Noted one of the solenoids in the BCC energizes when the key is turned to start the engine. Don’t recall having heard that action previously.

Both slides are tightly in place, pulled in. Don’t recall if ignition switch is tied to slides in some manner but would think dash wouldn’t light up and I could still communicate with the computer thru the OBD port, but I can’t.

Sorry for the scatter shooting of info. I’ve looked at and checked more but figured the above was enough to stimulate others thoughts as to what to look for.

My key concerns (other than the motorhome is dead) - is the dash light that says “Check Gauges” is lit up, the Fuel Gauge is pegged all the way to the right, and that I cannot communicate with the computer thru the OBDII port.

MrMark52 · 09-22-2021, 09:35 AM

Morning update -

Found PCM/TCM 10A fuse blown. Checked all remaining chassis fuses both under the hood and under the dash. All good except the one noted.

Replaced fuse, climbed in coach, turned key to On. Dash gauges light up normally, Fuel Gauge moves to its proper location (1/2 tank of gas, where it should be). “Check Gauges” light no longer illuminated. “Service Engine Soon” light illuminated.

Plugged my FoxWell scanner in - no set or pending codes for engine or transmission.

Attempted to start engine - nothing. Released the key, then reattempted - engine turns over and starts but sputters for about 2 seconds and dies. Get out to check fuse, blown.

Am thinking failed PCM. but need to do a thorough inch by inch inspection of the wiring PCM wiring harness.

Any thoughts would be appreciated ��

Ultra RV Products · 09-22-2021, 09:53 AM

Most likely the Transmission computer (module on the top). Unplug connectors going into it and try starting. If fuse does nit blow, you’ve found the issue as a failed TCM…

MrMark52 · 09-22-2021, 10:00 AM

Quote:

Originally Posted by Ultra RV Products

Most likely the Transmission computer (module on the top). Unplug connectors going into it and try starting. If fuse does nit blow, you’ve found the issue as a failed TCM…

Thanks Jon! I was just looking around for a phone number to call you.

I’ll go check it out and keep you and the thread posted.

MrMark52 · 09-22-2021, 03:40 PM

Well -

Things won’t be as gruesome financially as it was beginning to look.

After disconnecting the TCM from the coach which required removal of the doghouse once again, I replaced the fuse and started the engine. It sputtered momentarily and then ran normally. But hearing a weird bearing like rubbing noise coming from the area of the AC compressor, I saw the big 1-1/4” wire bundle that runs down the left hand side of the engine rubbing on the AC compressor pulley.

Quickly pulling that away as best I could, then reached up to kill the engine.

A bulk wire clamp on that wire bundle was never anchored anywhere. When nearing the RV Park last week, there was a deeper than expected hump in the road that likely jostled that wire bundle into the AC pulley. We only had about 2 miles to go to the park where the coach sat idle for 3 days.
It took about 30 miles of driving in 95 degree weather to soften the wire insulation up enough to let the bundle fall into the AC pulley.

So far it looks like 5 16ga and 1 8 or 10 ga wires affected. Can be spliced with butt connectors, wrap in tape, find some more loom covering to protect, and then replace and anchor the wire clamp.

Oh, reconnected the TCM - engine continued to run without issue. A little wire repair and hopefully life will be good once again as Mama will be happy as she pays the $600 14 mile tow bill we got Sunday to get the coach to a safe place.

Ultra RV Products · 09-22-2021, 07:42 PM

Nice find! Thanks for sharing.

George Schweikle · 09-23-2021, 07:14 AM

Thanks for posting. I'm gonna examine the wiring harness right away

And, Coach-Net would have towed your MH if you had previously bought a membership. "Closing the barn door after the horse is gone", etc.

Quote:

Originally Posted by MrMark52

.....life will be good once again as Mama will be happy as she pays the $600 14 mile tow bill we got Sunday to get the coach to a safe place.

MrMark52 · 09-23-2021, 09:01 AM

Quote:

Originally Posted by George Schweikle

Thanks for posting. I'm gonna examine the wiring harness right away

And, Coach-Net would have towed your MH if you had previously bought a membership. "Closing the barn door after the horse is gone", etc.

Thanks George! We had looked at Coach-Net - of all the “Roadside Assistance” plans out there it seems for every one that you hear good things about, you hear bad.
My view of it was/is - Sunday morning, lack of skilled staff who are following procedure rather than putting themselves in our shoes, comprehension, etc., etc. - issues that any of the Roadside Assistance services face these days.

It’s like my old days (‘80’s) of manufacturing industrial equipment - we had a Quality Control Department and they were often pleased when our companies quality issues were calculated at less than 2% - problem was, if you were one of the recipients of the failed piece of equipment, it was a 100% failure to you.

Same logic flows with Roadside Assistance responsiveness - except with our motor coaches the risks for life and property is far greater.

George Schweikle · 09-23-2021, 09:58 AM

Mark, I just checked my MH wiring for rotating elements interference and everything looks good. Thanks again for the suggestion.

Regarding roadside assistance plans. Several decades ago our first experiences were not good; for the first they couldn't even find us on a US highway. The second was an attempted scam to tow us 250 miles home, then charge us, when our plan was only "to the nearest service opportunity". This was with Good Sam where others have had good service. Fast forward to 2018 when Coach-Net towed both the motorhome, and our car trailer, 20 miles to an excellent service center.

I guess the last/best experience stays in one's memory but, from an overall statistical view, we didn't fare well overall. I did however renew with Coach-Net.

Quote:

Originally Posted by MrMark52

Thanks George! We had looked at Coach-Net - of all the “Roadside Assistance” plans out there it seems for every one that you hear good things about, you hear bad.
My view of it was/is - Sunday morning, lack of skilled staff who are following procedure rather than putting themselves in our shoes, comprehension, etc., etc. - issues that any of the Roadside Assistance services face these days.

It’s like my old days (‘80’s) of manufacturing industrial equipment - we had a Quality Control Department and they were often pleased when our companies quality issues were calculated at less than 2% - problem was, if you were one of the recipients of the failed piece of equipment, it was a 100% failure to you.

Same logic flows with Roadside Assistance responsiveness - except with our motor coaches the risks for life and property is far greater.

MrMark52 · 10-08-2021, 04:33 AM

As a new follow up on this experience -

The other day I went to my BIL’s house to retrieve the coach and bring her home. After my previously mentioned repairs, I had started the engine a few times and allowed to idle for at most 5 minutes.
I pulled out of his driveway and got about 2 blocks before a scraping metal sound began emanations from the engine area.
Pulling over and killing the engine, I removed the doghouse cover and restarted the engine.

The AC clutch was coming apart. Apparently the arcing of the alternator wire did some nasty damage to the clutch assembly.

I took my chances and easily drove the 5 miles or so to get the coach home.

New Sanden 4440 to replace the Delphi CA0120, filter drier, and idler pulley’s ordered. Looks like another project I store for the weekend. ��

George Schweikle · 10-08-2021, 06:34 AM

Mark, if you have an 8.1 engine, the serpentine belt tensioner is underneath the engine and its kinda awkward using a 3/8 breaker bar to release the belt tension. I needed to do this and someone mentioned using a small ratchet strap to hold the breaker bar against the tension. A great suggestion that made things easier when I just wanted to change the idler pulley.

Quote:

Originally Posted by MrMark52

...New Sanden 4440 to replace the Delphi CA0120, filter drier, and idler pulley’s ordered. Looks like another project I store for the weekend. ��