In prep for a upcoming road trip, I headed to the local shop for an oil change and tire balance, delayed by a day due to rotten weather. A mile down the road, I noticed no dash blower, wipers, or radio. The fans for the oil and tranny cooler wouldn't be working either, although prior experience showed that airflow was sufficient to keep the units well below danger. The instrument panel worked fine. Since I expected rain later, I returned home after 5 miles.

Since I had recently cleaned a bunch of grounds, I thought that could be the issue, but since nothing ran (Something should have with all the grounds I cleaned), that was suspect. Between rain showers yesterday, I determined that the power loss was on the hot side (jumped the IGN buss in the dash, and then the IGN relay coil in the battery compartment.) Everything worked normally in both tests.

So the problem is between the steering hub switch and the IGN coil. I removed (in Florida, that's "I took and removed") the steering wheel and discovered a split ring retainer for the switch plate impossible to remove without help. A visit to NAPA yielded the $10 tool necessary to depress the plate down to allow removal. That operation occurs tomorrow, and since I was bushed from my 4½, 7-stop shopping "spree"...

More as I get farther into it. As an aside, the IGN switch on older GM trucks is notoriously fragile.

quote:

As an aside, the IGN switch on older GM trucks is notoriously fragile.

as with many of their cars too....
especially when people hung a pound of other keys from them

Agree, but this is an entirely different design as are the related issues. The switch on these trucks is actuated by the ignition key, but is not integral nor tightly coupled.

Got the combination switch loose, but had to quit as the daily thunderstorms are approaching...

Will run a couple of more tests to be sure the switch is the issue (I'm beginning to suspect it's in the wiring, not the switch.)

Making (slow) progress; I've located the connector for the IGN switch on the steering column, and testing revealed there's a discontinuity in the wire to the coil on the relay. The wire is red from the IGN connector, but purple at the relay.

Rain and visits to the dentist and endodontist (pending root canal) have put things on temporary hold...kind of thankful I couldn't make the trip to SC, as the tooth flared up while I would have been on the road.

Still tracking things down...after tracing false leads. With all the connectors and wires on/in the steering column, I think GM stands for Galloping Mania.

Continuing gripe: I need to crawl under the Barth to get to the IGN buss relay, but thunder and lightning have been the order of the day - for weeks. Not going to be under a metal RV surrounded by trees...

Occam's Razor having been exhausted (the ignition switch has been replaced with no improvement), the issue is narrowed down to the IGN relay - which is on the frame rail, where, to access it, I'll have to remove several panels of the genset housing (already have some off).

I did discover that the videos on the 'net were inaccurate. The ignition electrical switch is actually mounted on the steering column, operated by a rod from the ignition lock, not embedded in the steering hub like it was in my '87 Ford E350. So most of the work on the hub was wasted...

I don't know if the P-3x chasses use the same system, but if they do, note that the switch for the tilt wheel (NAPA ECH KS6622) is different from the non-tilt.

Got access to the IGN relay today; it works from a hot lead. Why there's a blade fuse inline with a fusible link needs investigating. And I think it's going to take more time to stow the tools than actual manhours on the fix...

Discovered the relay is inop to to a bad ground - and that the blade fuse is 10A, should be 15A or 20A. I think it was added to fail before the fusible link, being easier to get to. I'll replace it with a auto-resetting 15A breaker. And the rear bus is powered directly off the relay, not through an in-dash bus.

I cleaned the local grounding bar, but the wire count is the same as original, so I don't know where the relay coil's ground wire goes, as it's in a sheath. Will check it out tomorrow with the signal tracer.

Since I had to partially disassemble the genset enclosure to gain access to the relay, it's impelled me to alter the area for easier access.

Really, REALLY sick and tired of the everyday rainstorms. Only 4 days of the last 7 weeks have been dry; river's up into the woods and starting to lap at the RV pad, so I moved the Barth onto the higher driveway.

At least I can still work on the few things left.

Geez Rusty I am happy to learn other folks love GM engineers as much as I do....My P30 electrical system is one holy mess. I hope you get it figured out soon, good luck.

The river's receded nicely, and the RV pad is drying. I plan to move the coach back to its spot Weds. Then I can start tracing the last wires, labeling the things I've identified, fixing the one last wire, and buttoning things up.

Returned the Barth to its nest - with the new issue being no power assist on the steering or brakes...The symptoms are that of a broken or slipped serpentine belt, but there was no "check gauges" light. The likely option is yet another broken shaft (the third) on the power steering pump. Will investigate tomorrow, being a swabbie, I reserve Wednesdays for Rope Yarn Sunday.

Oddly enough, the power assist took a couple of minutes to engage when I drove it up the driveway, but it worked fine. However, it's only about 150 yards.

Man it's like Rosanna Rosanna Danna said, "If it's not one thing it's another..."