Old Motorhome Issue - Any Idea What This Could Be?

[jcliff]

I'm at a loss on this and so is my RV guy. I have a '71 Sportscoach. She's stored in Reno and only goes out once a year, just to the Burn and back, this will her 8th year. My RV Daddy runs her once a month, she's been running great for several years with no big issues. But, for the last two years all of her lights have worked fine for the whole trip up until I hit Gate line 2 years ago, and Gerlach last year. Both times the headlights haven't worked after I turned the engine off. The engine has started back up fine, all of the other lights are fine, but no headlights. The problem is that she starts to overheat if she has to sit and idle, so I have to shut her down sometimes when waiting for the Gate line to pulse. For 2 years I've driven from Gate and Greeters to my Village with no headlights. Any idea what this could be and how to correct it?

[Jackass]

I'd look real close like at the headlight switch and it's electrical plug and wires, also there could be a breaker somewhere in there for the headlights that's weak... Triple check all wires and terminals that connect to the positive side battery terminal and there could be a few wires that are fusible links getting voltage at the positive cable down on the starter too.

[Token]

Is it thermal? I.e. only after the rig gets to normal running temperature and is “hot” does a restart cause failure in the lights?

I’m wondering if there is some kind of ignition relay that cuts the lights during starter cranking that gets stuck once warmed up.

That would fit the rather strange symptom.

[Jackass]

That's why I was thinking fusible links at the starter, close to tons of intense heat.

[Canoe]

... some kind of ignition relay that cuts the lights during starter cranking that gets stuck once warmed up.

Possibly combined with the headlight switch runs a headlight relay, instead of the lights directly.

Long shot. I've seen weird symptoms when the battery ground cable connection to the body/frame gets corroded.

[motskyroonmatick]

Replace your head light switch and the high low button switch on the floor. Make sure the contacts are relatively clean when reassembling. Switch is corroded leading to intermittent failure. The next mode of failure is head lights going out while you are driving. I successfully got one headlight to work when this happened to me by unplugging the other headlight. The current then was not enough to cause the resistance to build up causing the circuit to open in the corroded switch. Please replace the switches. New headlight fuse at the same time.

[XPTom]

thermal breaker.png

Does your 1971 have ye olde thermal breaker like this? Hot temps under hood can make a weak one even weaker... There is a simple bimetallic strip inside that opens when hot and closes when your mechanic trouble shoots it later in cooler temps.

[Jackass]

thermal breaker.png

Does your 1971 have ye olde thermal breaker like this? Hot temps under hood can make a weak one even weaker... There is a simple bimetallic strip inside that opens when hot and closes when your mechanic trouble shoots it later in cooler temps.

That's exactly the kind I was referring to!

A faulty one of these can leave you scratching your head while chasing your own tail.

Link this thread to your RV daddy in Reno and tell him to get after it, time is ticking...

[Captain Goddammit]

You might wanna look into why it overheats when idling, that’s not right.
The three biggest things that put old RVs on the side of the road are old tires, transmissions, and overheating.
If you don’t take care of those three, Life Lessons are in your future.

The early-70s Sportscoach is a cool rig.

[Popeye]

For the overheating problem, get a can of spray condenser cleaner- I just saw them at Home Depot. Spray the radiator fins and wash out with a hose. You don't want to use a pressure washer. Check your fan belt tension and that the fan is not covered in gunk.

[jcliff]

Is it thermal? I.e. only after the rig gets to normal running temperature and is “hot” does a restart cause failure in the lights?

I’m wondering if there is some kind of ignition relay that cuts the lights during starter cranking that gets stuck once warmed up.

That would fit the rather strange symptom.

Sorry for the delay in responding! Yeah, this sums it up. Headlights only go out when she's running hot. I sent the thread replies to my RV guy in Reno. Not sure what he'll be able to figure out before this Wednesday! Just in case I got 2 high-powered tactical flashlights! We'll tape em' down in front if needed!

Thanks for the suggestions and I'll follow-up with what we come up with!

[XPTom]

Bump...… any luck with our guesses?

[Jackass]

Yeah, what happened?

[Jackass]

Sorry for the delay in responding! Yeah, this sums it up. Headlights only go out when she's running hot. I sent the thread replies to my RV guy in Reno. Not sure what he'll be able to figure out before this Wednesday! Just in case I got 2 high-powered tactical flashlights! We'll tape em' down in front if needed!

Thanks for the suggestions and I'll follow-up with what we come up with!

[unjonharley]

Old motor homes are notoriously a peace of shit, that breakdown in traffic.. How many can't make it back to Gerlach .. Do you really need the drama of a pile of junk .. It's a camping trip, get a tent ..

[Captain Goddammit]

Oh can it you old grouch... my old motorhome... oh wait, it broke down and died in Oregon on the way to ‘08 and that was the last time I saw it..

Never mind.