Limping home when alternator belt fails.

I awoke to a flat start battery in my Tiger (Silverado chassis) one AM in an Oklahoma rest area on I-40. Since I had just re-done the house battery to change it from 1 underhood to 2 in a DIY'd rack under the rear, I knew what wire did what. I carry a jumper wire with small alligator clips on both ends to help me do one-man trouble-shooting.

I had just enough juice in the start battery to get the Onan running, so I jumped from the old front underhood positive house battery wiring over the engine to the positive post on the start battery. I went back in and fixed and ate breakfast, and voila, the start battery was up enough to crank the 8.1.

I had planned to remove the underhood house battery's wiring, but that event convinced me to leave it. I also now carry a heavier-gauge wire with bigger clips. Yes, I'd rig this up again if I had a alternator failure, and keep the Onan running.

Jim, "Mo' coffee!"

My coach and house batteries are in the same bay, so jumping from one set to another is simple. The downside though, is that my converter doesn't have a high enough charge rate to keep up if too many accessories are running. My fix for that is the 110-volt outlet in the bay that with the generator running lets me plug in the 30-amp battery charger I carry with us.

Well well well…. posing the question the way I did certainly resulted in solutions that I had not thought of. The most usable for my situation with a broken belt senario is my set-up with the A/C compressor belt alternator belt being the same. The compressor seized up on my unit and my concern, after I disconnected the electrical connection so that it would not be activated by mistakenly turning on the defroster, is the seizing up of the clutch assembly pulley bearings. If that occurred the belts would burn up and hence no alternator. Using the generators 110 circuit to drive a small charger connected to the engine battery as suggested, is the better option for me. That will at least get me home for a more complete repair to be done by my preferred repairer. Thanks all.

As a further enhanced solution to my previous post, couldn't I use the gen set to charge the house battery which is connected to the isolator, but does not go any further. This set up allows the isolator to direct the current from the alternator to where it is need the most. If I jump the isolator by bridging the house battery posts to the engine battery posts, wouldn't that power up the engine battery in the senerio I described?

tpi wrote:
Maybe..

You have to determine what isolates the house 12 volt system from the vehicle 12 volt system. Some have diode, others have relay, and some may have a switch or no isolation at all. The diode would be problematic for backfeeding.

My class C uses a relay which clicks in when ignition is on,

Possibly not. The "relay" in our MH is powered from within the alternator.

connecting the two systems. Getting engine started, then start generator and power converter should work. Probably best to operate least amount of vehicle accessories possible. I'm counting on it as a backup to alternator electrical failure.

But you could "jump" across the relay input and output.

Interesting thread since I'm going thru a similar situation presently. Alternator quit working for whatever reason and need to drive to my dealer 10-12 miles to get it looked at. Plan on running my genny which will keep the battery charged as I drive. On my coach, the converter will charge both house and chassis batteries when on shore power. Conversely, the alternator will charge all batteries as well while underway. Newmar uses a "BIRD" system = Bi-directional Isolator Relay Delay, which allows the multi-function charging I described. Suspect many other coaches use that or a similar system as well.

Dating my self, but years ago when I had a belt break I was able to get to help by tying a pair of panty hose around the pully's. Probably won't work with todays motors, but this thread brought back memories...

for standard V groove belts
there is an "emg belt kit" you can buy at auto stores

it is a cut to fit system adjustable in size

to use to get you to a repair facility

chainegang wrote:
Can you back feed on board generator power through converter to engine battery when alternator belt fails so as to limp home? Water pump and power steering on separate belt.
Dodge B350 w/ 360 engine.

If you know what you are doing it will work fine.

3 dog nights wrote:
Dating my self, but years ago when I had a belt break I was able to get to help by tying a pair of panty hose around the pully's. Probably won't work with todays motors, but this thread brought back memories...

Wrapped the hose around the pully's what?