3126 no start issue

[VanDiemen23]

1999 Beaver. Last started about six weeks ago. I had done some electrical work (R&R the inverter, fixed a broken wire in the solar harness) but the coach started fine after all of that.

Today, when attempting to start, there was no pre-heat indication, no cycling of the pac brake, and the transmission controller doesn't come on. Turning the key results in no starter engagement. Both banks of batteries are showing 13.6v.

Big boy relay actuates, generator starts, various other electrical functions seem fine.

electric step goes nuts. I usually see that as a low voltage indication, but there's no chattering relays like Ive seen before and the voltage isn't that low.

Thoughts?

[Skip426]

Yours is best described as a " no crank " condition . No start is cranking but not running .

The root of your problem will be the shift pad not lighting up . If the control modules don't see neutral the starter engagement is not allowed.

There is an inline fuse that provides battery power to the Cat ECM , but I'm sure that wouldn't shut down the shift pad.

There may be on your chassis a VIM ( Vehicle Interface Module ) with fuses and relays related to power to the trans control module .
Below are pictures of my VIM and the fuses and relays inside , look around your coach for a similar module. It's about 5 " square and 3" high and mine is in the engine compartment. Yellow circle.

[VanDiemen23]

The beavers have this aluminum box with a bunch of weatherpack fuse holders and a couple of relays on it. My low voltage problem originally was caused by a break inside this box not delivering solar to the chassis batteries. I bypassed all of that and thought I had it licked. In working on the box I had everything pulled off. I bet one of those relays is the culprit. I'l re-seat it as well as all the connectors on the trans controllers.

There's no schematic for this year beaver and I've patched a lot together from other years and models, which kind of gives you a general idea, but stuff like this is not there at all.

They potted that box solid and it has three long cable bundles that go to god knows where, so hopefully it isn't something else in there!

Many thanks!

[ronster]

If there is no power to the Allison control module engine won't crank as the nuetral safety switch switch is inside it.Most of the time the hot and ground wires go directly to the batteries,with an inline fuse holder.

[VanDiemen23]

well last weekend I finally got serious about this thing.

I chopped the "Aux box" out of the harness and buzzed everything out. whatever problem was there that caused me to wire around the solar issue was now gone.

i started eliminating all the knucklehead muti-splices that Beaver/Safari put in, added a terminal strip to make the connections and put it all back together.

Fired right up.

One of my good friends used to call stuff like this "female problems". As in - it just wants you to pay attention to it.

After being frustrated for about the third of fourth time in trying to find cables in all the mess of cabling, most of which is a good tow feet or more longer than what is required to do the job, I've gotten serious and pulled all the big conductors out to get some room and i'm spending a week shortening long cables and re-routing stuff.

The knuckleheads even used OEM CAT fuel lines that are easily 18" too long and just looped them about rather than shortening them.