MEXICOWANDERER wrote:
I get passed on highways by cars running on emergency spare tires at 80 mph. Just because I don't see them do somersaults off into the canyon does not mean the practice is the most intelligent. Hell my uncle in Montana controlled a pedestal grinder with a foot dimmer switch, and down here an English National Geographic magazine stands a good chance of being dismembered in an outhouse. A friend loaded his '50 Chevy pickup with three and a quarter tons of asphalt and limped six miles to his house to pave his driveway. IT WORKED! Is this abuse "recommended"?
Relays have ratings. The ratings including duty cycle should be obeyed. The only constant duty 12-volt relay I know of rated for 400 amperes break costs around two hundred dollars. "It Works!" is probably the biggest screw-up in the English language. It leads to "It Doesn't Work!" and that is guaranteed to happen at the worst freakin' possible time.
Do it right por favor. Find the ratings and obey them. BTW a hot non gear reduction starter motor starting say a 454 Chevrolet engine at 20 degrees can draw in excess of 400 amperes inrush and break. Guesswork leads to disappointment.
Motorhomes last 35 years
1. use a BIG BOY solenoid, rated at 200 amps continuous duty and is found on almost ALL RV Diesel motorhomes
2. The simple Ford(starter solenoid) looking Silver solenoid (NOT FORD but looks like it), can have either 4 posts or 3 posts, rated at 100 amps. COMMON on almost all Gasoline Motorhomes and some older Diesels. THIS solenoid is rated at continuous duty and the LARGE amp draw to start a chassis engine for a few seconds.
3. IF you look at a Auto parts catalogue, you will see hundreds of silver solenoids that all look the same, the problem is, they ALL have different specs and ratings and operation. Just buying a solenoid that "looks" like the one you have without knowing what its rating is will be a cause for failure. THIS IS A COMMON PROBLEM I SEE.
4. Except for very few large Diesels, all the Battery disconnect relay's are rated at no more than 100 amps continuous duty. That is why you never connect an Inverter or the emergency start circuit thru one.
4. Mexwanderer, I don't know if you are posting stating that ALL motorhomes are not designed right or you are just shooting your knowledge out there. Doug
