E450 Jayco no power, no start, possible causes?

[Patchworks]

Hi, I'm hoping someone can help me figure this one out.

I have a 2006 Jayco Grayhawk on a Ford E450 Triton V10.

Just purchased from private party. It was having issues with the inverter not working, so we found a cable loose in the coach battery compartment, it had a tiny piece of white tape with what looked like a tiny - symbol on it. So we hooked it to the neg post on the battery.

It only took about 3 minutes and there was the nasty burning wires smell from the engine compartment, the truck died and we hastily unhooked that coach battery.

Now there is no power from the cab ignition at all. No lights, bells, nothing. Turn key, dead stick. Meter says truck battery is OK.

There is a solenoid type thing on the firewall above the air filter that got very hot, hot enough to fry the rubber boot over the post. It has a tiny gray circuit breaker box thing (I think?) next to it.

I'm thinking we (OK, I) reversed the cables on the coach battery, obviously, but what is the downstream damage I should be looking for? Main fuses in engine box all look OK. Maybe a fusible link?

I'm afraid I know what I fried, but hope springs eternal someone has a happier, less expensive idea.

Thank you!
Sue

[westend]

Are you having problems with 12V? That would be the converter that is charging the battery and powering the system, not the inverter, that inputs 12V and outputs 120V.

Quick troubleshooting: Connect to shore power. Measure voltage at output of converter (this should be 13.5 V or higher). Measure voltage at battery. It should be close to converter voltage measured.

[Patchworks]

Not sure on the inverter, haven't got that far. I'll check tomorrow.

For today our "dead truck" problem is solved! It was right near the battery as said! The big fusible link went from the battery positive along the top wall in front of the radiator and over to the main fuse box. That whole wire had to be replaced.

The local Ford dealer said he could get one from Denver in 4 days for $210.00. We went to Spaldings truck salvage yard here in Spokane and got one for $19.95. Put it in, fired right up. Huge sigh of relief!:B

I'll take a look at the inverter in the morning. Basically it's not putting out power to start the gennie or move the slides. They start/move fine on shore or engine power.

I'm a-scaired to go mess with it again after this adventure!:E

Thanks for all the help guys!

Sue

[pianotuna]

Hi Sue,

What are the inverter problems? Make and model?

[Patchworks]

I do believe we found the problem, directly under the battery compartment is a fusible link. It is one very crispy critter.

Off to Autozone again.....

Hmm, make that the Ford dealership. 😞

[westend]

Sue,
Got meter?

[Patchworks]

pianotuna wrote:

Very nicely put where you can't see and there is little room to work. Check them all.

Ah yes, been doing the fuse box limbo under there - my bad luck to be the smallest person here. So far no joy. :h

Thank you for the help! Back at it in the morning.

Sue

[pianotuna]

Hi Sue,

There is a fuse box near the brake fluid container on my 2004 V-10. The "house" solenoid is fused at 60 amps inside that box. There are also relays there for the 7 pin trailer connector. There are other relays as well. I would do a continuity test on all the fuses.

There are another set of fuses under the dash on the drivers side. Very nicely put where you can't see and there is little room to work. Check them all.

There are at least two solenoids--on my 2004, one for the starter is in by the passengers side headlight area. Another is down below the battery--that is the one for the house batteries.

You can try jumpering across each solenoid, but be careful.

[Patchworks]

OK, we will check that tomorrow. So that isolator is separating the chassis and coach batteries? And the reverse polarity cooked that?
(My job was driving, not fixing! Motor pool did that!)

I did pull that solenoid part off and took it to Autozone, they had no clue what it was, said it must be a RV thing. Well, yeah.:R

I put it back.

Hopefully we can get it started. Once it is running again it goes to a shop to figure out the inverter problem.

The $4.99 voltage meter says the main engine battery is good but it's been wrong before on batteries.

Thanks for the quick response!

Sue

[westend]

That solenoid type thing is probably a battery isolator and you may have burnt the contactors by the sound of it. The circuit breaker may have been damaged also. Best recourse for all of this is to see where you have continuity from the chassis battery to the various circuits (ignition, aux power, etc). I think you'll find your major problems close to the battery.