Almost all motorhomes have such a button. It's really intended for use if the engine starting battery runs down, not for a specific starter problem.
Hot starting problems are a different topic. Does your MH refuse to crank, the starter just generally overheat, or crank and not start?. While there are known problems of insufficient air flow to starters on 8.1 L chassis, there was a different problem back in the 70's and 80's. We had a '76 Midas Mini on a GM class C chassis, and sometimes it wouldn't crank when hot. It turned out that GM had undersized the wire leading to the starter solenoid, and it wouldn't carry sufficient current when hot (since resistance increases with heat). The wire ran from the battery, to the ignition switch, to the neutral start switch on the transmission, then to the starter, and was barely sufficient to carry current when cool. We sometimes waited 1/2 hour or more for the thing to cool down so the starter would crank. Before that, the starter solenoid wouldn't even click. I installed a relay to run current directly from the battery to the starter, and later found that GM had a factory bulletin to add such a relay for GM class C and A motorhome chassis.
If your engine cranks, but doesn't start when hot, it may be something else. A '91 may still be a carburator engine, and these things need rebuilding after many years.
Originally Posted by sportz
We bought a 91 Fleetwood Searcher Class C on a Chevy G30 chassis. It has a "Emergency Start Button" under the dash that engages the coach battery. It's there because the starter is too close to the exhaust manifold. I have installed a metal heatshield I got from NAPA. Did'nt help! I was told, and I've seen it, that there's a RamAir system for the 8.1L Chevy Workhorse engine because it has the same problem although the 8.1L is mounted on class A M/H's. Has anyone used this Chevy retrofit that they deny having or, have you made your own to blow air on the manifold/starter? This problem only occurs after driving more than 3 hours.