Tonight's Fun with the Allegro

[Jim Stoltz]

I'm headed to the Pocono Raceway next Friday for the NASCAR race. But before then, my daughter is having some friends over to camp out in the RV. I figured I'd move it to the driveway and level it. 

It won't start. Not getting any fuel.

I checked the fuel filter at the tank. It's full of fuel so I figure the pump is drawing it out of the tank at least.

I took the fuel feed off at the carb and cranked it. Nothing.

I unhooked the feed at the pump and fuel poured out. Pump isn't pumping up to the carb. Easy enough, right?

Installed new pump and it does the same thing.

I replaced the fuel filter. Same thing.

I unhooked the feed from the tank and dipped it in a 5-gallon can of gas. Fuel was drawn into the filter but not the whole way to the carb (again - new pump and filter).

I put compressed air on the line that runs to the pump. I hear sssssssssssssssssss somewhere. The line goes from rubber to metal at the tank, and then metal to rubber right at the fuel pump. The friggin hose clamp up by the pump had come loose and it couldn't draw fuel from the tank. Two turns of a screwdriver and it fired right up. Expensive lesson both in time and parts.

Great - it runs now. My relief turned to frustration when I needed to pump up the air suspension to get the butt off the ground. Pump won't run. I had just installed a new solenoid instead of a relay. It was working great, but not today. I jumped from the constant hot across to the hot side of the solenoid and the pump ran. Went up front and the controls for the air suspension are dark. Can't get air into the bags. Jumping the power across that solenoid back fed juice to the controller box. I found a baked ACC fuse but replacing it didn't fix it. 

I couldn't find my scan of the wiring diagram so I googled it. I came up with my own scan from a couple of years ago. Go figure. It looks pretty simple. Nothing really "electronic" to cook - all switches. I need to find out where the control box should be getting power from and trace it back.

Worst case I can manually air up the bags but that's a pain because the left one leaks. Grrrr.

Moral of the story: With the fuel thing look for simple stuff first. With the air suspension - don't go jumping wires until you're sure what the implications might be. I thought that the controller was isolated from that circuit.

[Rick Faunce]

Jim, Is this a Jet suspension? Mine just has an inline fuse feeding the panel with the switches under the dash. If that is the suspension you have I have the book on it.

Rick

[Jim Stoltz]

Yes it is a Jet suspension. I looked for an inline fuse - probably not hard enough- that has to be the problem. I had to rewire it when I first got it because the pump and solenoid had failed. It looks like the controller box is getting its power from a harness in the back by the pump, which is the circuit I jumped. 

[Rick Faunce]

Manual attached, Power goes all the way to the back. I remember having a problem with mine but for the life of me I cannot remember where the fuse was!

[Jim Stoltz]

Thanks!

Let the games (troubleshooting) begin!

[Rick Faunce]

I put a much bigger Viair 444c compressor on mine and also replaced the solenoid with a relay. Also ran a bigger ground cable directly to the frame.

[Rick Faunce]

Come to think of it, I ran a new 8 gauge positive cable all the way back to the compressor relay from the front. I knew the new compressor would draw more power then the original wiring could handle. I put the 30 amp inline fuse in that wire up front and if I remember correctly the control wire comes off of that one where it meets the relay. I will see if I can get under it tomorrow if you can't find anything.

[Jim Stoltz]

I did the same thing. The original wiring was too small. I ran 4-gauge cable with a circuit breaker mounted up by the battery. I also got a much bigger compressor. The 30-amp relays I was using were cooking so I replaced them with a beefy solenoid. I moved everything inside under one of the beds. 

I really don't remember what I did with the power for the controller. There is a blue wire that comes off the black harness that runs up from the back. Unless I really baked that controller (which I doubt) I must be missing some sort of power feed to it. The wires that come out of it are all in the same gray-coated bundle. I need to get under it to see what goes where. 

Thanks for your help so far!

[Jim Stoltz]

I have no power to the controller. It's a strange setup, but it gets its key-on power from a splice way back at the pump. There's a key-on wire plugged into the fuse box. That wire runs the whole way back to the pressure switch for the pump. It splits there and runs the whole way back up to the controller to power it. 

I'm trying to replay all of the events back in my head. The first thing that I *think* happened was my new solenoid stopped working. But if I jumped a constant hot across to the switch terminal it would run. And I *think* at that point I still had power to the controller. When I removed the jumper the pump ran as it should and the controller shut it off.

Last night when I went out I couldn't get the pump to run so I jumped it again. This time it wouldn't stay running and the controller had no power. Then I found the blown "ACC" fuse to which the controller wire is hooked up.

After replacing the fuse, I checked for key-on voltage back at the pump and there isn't any, so that means the controller isn't getting any power. I jumped from a constant hot to that wire and got a little spark meaning there's some load on it somewhere but the controller still didn't light up and the switches didn't do anything.

I took the controller out and pulled the cover off of it. As I suspected there's nothing in there to fry. There's just a few switches and none of the wires appear to be melted or even have gotten warm.

I took a look at the wiring and it's pretty clever but very simple. All the controller is doing is switching that key-on power from the switches on the box ("MANUAL" setting) or the level sensors in the back ("AUTO" setting). The ground on the box is just for the lights (the manual/auto switch is lighted and there's a light for when the pump is running). 

I hooked power up directly to the UP/DOWN switches and they operate the solenoids but the lighted switch isn't working (bulb must be out). Yes, I tested it earlier to make sure it really wasn't getting power and it wasn't just a blown bulb.

Long story longer, I got this solenoid: http://www.amazon.com/CONTINUOUS-SOLENOID-RELAY-CARTS-1114208/dp/B0...

All I can figure is that it is drawing too much power. It baked that ACC fuse. I have no idea why I can't get key-on power back to the solenoid control wire and therefore the controller. I need to check that next but at least I know the system works - just needs juice.

[Rick Faunce]

Jim, It appears that the power for the control box comes from the rear off of the same circuit as the pressure switch. It ties into the blue wire before the pressure switch and returns to the front and ties into the auto/manual switch. If you do not have power at the auto manual switch then I would look at the connection where they tie together between the blue and black at the pressure switch. Did you say you moved everything inside under a bed? Does that mean the compressor too? If so the compressor may be overheating and shutting down on thermal overload.

[Jim Stoltz]

Yes I moved everything under a bed. There is lots of ventilation under there and the compressor doesn't get hot. 

I checked where the blue and black come together at the back and it looks okay. I put the controller back together and plugged it in and now it works! I must have a loose connection somewhere on that blue/black run.

The compressor ran, the solenoid shut it off. I put some air in the bags and the compressor tried to run again and it tripped the 30-amp breaker. I reset the breaker and turned it back on and it was fine again. Not sure what that's about, but it's a totally different circuit and problem.

[Rick Faunce]

Check your ground connection at the frame and make sure it is clean, a dirty connection will create a lot of resistance.

[Rick Faunce]

What kind of compressor is it and what are the starting specs? Drawing too many amps at startup maybe?