CAT 7 Diesel Pusher (Freightliner) Engine/Electronics Issue

[willmoon]

Hello, everyone,

I'm brand new to this forum and a new RV'er. I just bought a 2005 Alpha See Ya in great condition, less than 10k miles and barely used. I bought it from a dealer in Charleston, SC, who bought it at auction in Florida. He drove it 400 miles from Florida to Charleston and said it ran great. I drove it home to Lugoff, SC from Charleston (about 110 miles or so) and it "ran great". Being a new RV'er, my wife and I took it up to the high school parking lot on Sunday to practice backing up (it's a 40 footer). After about 45 minutes of practice (the engine barely got out of idle the whole time), everything on the chassis died: engine and all electronics, including the dashboard. This happened just as my wife was opening the entry door and I was putting the tranny in neutral and putting on the air parking brake. I'm not sure as to the order of things, but suddenly it all died. After about 10 minutes of "oh my, what do we do now?" hand wringing, on a whim, I pushed the accelerator peddle all the way to the floor and heard a click, and everything came back on! Thank God! It drove home just fine. The engine did not seem overheated when the problem happened, there were no warning lights, no warning at all, just bang, it all shut off. Has this ever happened to anyone else? Does anyone have any idea what might have happened and why or if my pushing the peddle down reset something? Now I'm a little worried it may happen again, this time on the highway. Any help anyone could give would be MUCH appreciated. I've been all over the internet forums, freightliner web site, Caterpillar web site, etc., etc. and found nothing.

[Big_Katuna]

A short version with what you did to fix might help the rest of us.

[RayChez]

WillMoon, I had a similar problem like you described many years ago and it turned out to be the ignition switch. I pulled the switch out of the dash and noticed that the back end of the switch had sprung out some. I pushed it together and secured it so that it would stay together and I never have had the problem anymore. Apparently every time I would hit a bump it acted as if somebody was turning the switch off. That is what let me directly to the ignition switch.

[tporter]

I sent you a PM. I might be able to help you but it will take too long for me to type all the symptoms that I had as well as how I fixed the coach.

[wolfe10]

willmoon wrote:
Brett,

Thank you SO much for responding to my post. Let me see if I understand what you are saying in your first sentence: are you saying that if everything works when the ignition switch is ON (transmission shift pad, dash HVAC fan, gauges, etc) the likely suspect is the ignition solenoid (more likely), ignition switch or wiring between the two? If nothing works when the ignition switch is on (no instrumentation at all, no transmission shift pad, no dash HVAC fan, no gauges...) then it is NOT the solenoid or ignition switch? Because the latter case is the situation I experienced. Absolutely no power to the chassis at all. Turning the ignition switch from OFF to ON or from ON to START did absolutely nothing (instrumentation did not respond). I could, however, start the generator and use any coach 12v power (lights, fans, etc.).

Thanks,
Will

If NOTHING works with the key on that normally works with the key on, the ignition switch or ignition solenoid is the likely suspect (i.e. bad).

Your symptoms would suggest a bad solenoid, though checking battery connections and voltage IS a good idea. Clearly the solenoid will not work if battery is dead. But with everything returning to working, unlikely the battery is bad-- yes, could be a loose connection, but few batteries go from completely dead to good enough to start the coach a little later.

[Mandalay_Parr]

You may have bad batteries.

[willmoon]

Brett,

Thank you SO much for responding to my post. Let me see if I understand what you are saying in your first sentence: are you saying that if everything works when the ignition switch is ON (transmission shift pad, dash HVAC fan, gauges, etc) the likely suspect is the ignition solenoid (more likely), ignition switch or wiring between the two? If nothing works when the ignition switch is on (no instrumentation at all, no transmission shift pad, no dash HVAC fan, no gauges...) then it is NOT the solenoid or ignition switch? Because the latter case is the situation I experienced. Absolutely no power to the chassis at all. Turning the ignition switch from OFF to ON or from ON to START did absolutely nothing (instrumentation did not respond). I could, however, start the generator and use any coach 12v power (lights, fans, etc.).

Thanks,
Will

[wolfe10]

If everything that only works when the ignition switch is ON (transmission shift pad, dash HVAC fan, gauges, etc) is not working the likely suspect is the ignition solenoid (more likely), ignition switch or wiring between the two.

Freightliner may be able to help you locate the ignition solenoid.

To test:

Will have two large lugs-- one reading chassis battery voltage all the time. The other should read the same voltage when and only when the ignition switch is on.

There will be either one or two small terminals. If only one, it will be the signal wire from the ignition switch. If two, the other will be ground. If only one, the ground is through the metal body.

If you do not get chassis battery voltage at the "other" large lug when the ignition is on, check for voltage at the small positive signal wire (should have 12 VDC positive). If that is what it has, but the other large lug doesn't have chassis battery voltage, the solenoid is BAD. Tapping on it may work short term.

If no voltage at the small signal wire with the ignition on, remove the small wire and use a jumper wire from the chassis battery large lug to the positive small signal wire. Small wire is fine-- it takes less than one amp to close the relay.

Emergency work around: Label all the wires on one large lug. Remove then and ADD them to the other large lug. All you have done is manually done what the ignition switch and solenoid do for you. Be sure to return wires to original position when you stop.