HELP! It won't START!!

[theserver2]

After reading your posts for several months (and learning TONS I might add, thank you very much ), I find myself needing help with an electrical issue that the local mechanics and I just can't solve.
Have a '96 Signature that, when the ignition key is turned on, the only display that lights up on the dash is for the brake; the fuel gauge registers but really nothing else. You can hear a solenoid click when the key is turned but nothing's happening, none of the usual bells and whistles that serenade ya when the key's turned on and obviously, the coach won't start.
I replaced the Allen-Bradley power supply unit today after finding there was power coming in but nothing going out. I don't know what caused that to happen, maybe a faulty relay, solenoid, or power surge? I know I don't want to have to replace very many of these power units. Wow! Expensive!
At least there is now power going through the unit to the CPU et al. but still nothing with the ignition.
We replaced the ignition relay in the front electrical panel, checked all the fuses in the front and rear run panels (didn't find any blown fuses), as well as the solenoid (accessory, I believe) that's in the front electric panel (equal volts in and out). The chassis' battery cut-off switch shows equal volts in and out, and there is power going into the back of the ignition where the key goes.
There is an ignition relay in the rear engine compartment but which one it is is anybody's guess. The schematic I got from Monaco doesn't match this coach's engine compt. design. I thought maybe someone had another suggestion before I start replacing all 15 of those relays.
Any suggestions? Is there another solenoid somewhere that I'm missing? There are only 2 in the rear engine compartment - a large one that we think is for the starter and a smaller one that goes to the house's battery cut-off switch. There is equal volts in and out of each of these.
Any thoughts? The coach went in for routine service and the guys at the shop are scratching their heads since their specialty is diesel motors, not motorhome electronics.
Thank you for reading this and any suggestions you might have.

[Pusherpilot]

Did you try the boost switch? Also what voltage are you showing out of the chassis batteries? What happens to that voltage when you turn the key to start?
Ron

[oldvectra]

This rig is in that prime age where all the grounds that attach to the frame probably have some corrosion on them.

[theserver2]

I did try the boost switch because the coach will not start w/o using the boost. Never has, even though more than one mechanic has tried to figure out why.
You can hear the solenoid "click" when pushing the boost button but nothing else happens.
The engine batteries are new. Not sure what the voltage is but will check Monday.

[itdave]

I love IRV2 also, but here is a group called Monacoers@yahoogroups.com that have a lot of knowledge about older Monaco Coaches. You have to have a Yahoo ID and request membership to be able to view their message and post threads. Go to Yahoo.com select groups and then search for Monaco.

[theserver2]

Thank you!!

[theserver2]

Put in a new Allen Bradley power supply yesterday, most dash gauges came on but not the ignition. Went thru fuses today and found an ignition relay fuse had blown. Replaced it, everything came on, it tried to start but sounded almost like the engine batteries were low or the starter wasn't quite engaged. Left the chassis and house power on. By the time my son-in-law the mechanic got to where the coach sits, we were back to no power going through the Allen Bradley power unit, no ignition, nothing. Turned chassis cut-off switch off for a minute, thinking it might reset something, and still nothing at the dash. No red light indicating that the power unit's on. The fuse that AB puts in the 1746-P3 did not blow. Can a circuit board get fried w/o blowing the fuse?
Do you know anyone in central IL that makes house calls?? :(