I was troubleshooting an electrical problem in my B300 RV when I created a new trouble! :frusty:
While checking running lights to see if they worked, I bumped the unfastened instrument cluster and its electrical circuits hit the edge of the metal dash housing. Bzzzapp! The running engine "stumbled" but kept going. I shut it off, examined everything for burned or otherwise damaged components (including fuses - none blown) and tried to start the engine. Nothing - except a small burn mark at the point of contact with the dash.
This is one reason why I don't work as an automotive electric technician. :facepalm:
Everything one would expect to work with the switch in the "run" and "acc" positions works. Good thing the short lasted less than a second.
I got out my multitester, removed the ignition, and tested it according to the instructions in the Haynes manual.
IGN 1, key ON: FAIL (However, with the key turned to "start," current passes through)
IGN 2, key OFF: Pass
ACC, key ACC: Pass
ST(ART), key START: Pass (!)
The Haynes text reads in part, "[Turn key to Run], connect the [ohmmeter probes] to the B (battery +) terminal and either of the I (ignition) terminals - there should be continuity." Either terminal? Does that mean that only one or the other needs to allow continuity? I'd think it'd be both. Any thoughts?
Personally, I hope the internal switch connection is what got "fried," because it's easier to replace the switch than find wherever the circuit got broken.