Hydraulic Relay Question

[Lndeatr]

2013 300C – It’s been a while since I posted anything here. I posted a different issue in the Cyclone garage section as well as the plumbing section.

I have scoured through the hydraulic posts and my issue is not uncommon though I have a little more detail that I couldn't find. Basically since shortly after I bought the unit (new) the 50 amp relay on the hydraulic pump would open when pulling in the main slideout or lifting the front legs. I have just dealt with it up to now but it is now taking 5 or 6 resets to get the legs up. Thinking it was a bad relay, I swapped it with another 50 amp relay from another circuit and it did the same thing. I am hesitant to bump it up to 50 since the pump works fine for some functions.

I got to wondering why it will lift the trailer with no problem, why the main slider goes out with no problem, and why the bedroom slider is never an issue (I assumed it wasn’t putting as much of a load since it is half the size). As noted above, it only has an issue lifting the legs and bringing in the main slideout.

Unfortunately a garbage can against the rear of the trailer caught fire and now it is back at the dealer where I bought it for repairs. I bought the Route 66 extended warranty from them so I thought I would have them look at it. My concern is there is a problem and installing the 80 amp relay will just mask it. Since it is a warranty issue now, I want to make sure it is resolved completely. I know they will likely want to make the easiest repair.

Any thoughts on why the relay only opens when it does? Has anyone had the same symptoms and how did you resolve it?

 

[danemayer]

The breaker can trip repeatedly for multiple reasons including:

Weak breaker
Low battery voltage
Loose, dirty, corroded battery terminals
Loose, dirty, corroded ground connections
Loose, dirty, corroded connections at the pump
Mechanical binds

Since you've already changed the breaker, it's probably not that.

I'd look real hard at the connections, especially including the grounds.

 

[Lndeatr]

The breaker can trip repeatedly for multiple reasons including:

Weak breaker
Low battery voltage
Loose, dirty, corroded battery terminals
Loose, dirty, corroded ground connections
Loose, dirty, corroded connections at the pump
Mechanical binds

Since you've already changed the breaker, it's probably not that.

I'd look real hard at the connections, especially including the grounds.

Went through all the connections. Cleaned and tightened and new ends on some. Confirmed voltage was good. I work on precision agricultural electronics (farm machinery) and bad connections, bad grounds and low voltage are the #1 problem we find. That was the first thing I did. 12 volt lights got brighter but no change on the hydraulics. Is this a 2 direction pump or us the reverse direction controlled by valves?


Sent from my iPhone using Tapatalk

 

[danemayer]

It's a 2 direction pump. The slide rocker switches reverse the polarity of power to the motor to reverse direction.

 

[Lndeatr]

It's a 2 direction pump. The slide rocker switches reverse the polarity of power to the motor to reverse direction.

Seems to me the issue is when the pump is running in the direction that raises the legs and pulls the main slide out in. Not sure it is related to load. The bedroom slide is small and narrow and probably doesn't run the pump long enough to open the relay. Hopefully the service department where I bought it has a working knowledge of hydraulics.

 

[wdk450]

Since you have gotten some good advice, have good experience in repairing complex ag equipment, and still have your problem, I think you need to do some in depth diagnosis. I suggest cliping on a DVM to the relay coil terminals, and closely monitoring the voltage there as the loads are applied to see if the coil drive voltage drops. Unless the replacement relay you installed has the exact same problem as the previous one, this seems to me to be the area to check. Another way you could check this is to take the coil inputs out of the trailer circuit, and try driving them with an external source of 12 volts DC like a separate battery or battery charger, and seeing if the relay/pump dropout still happens.

Good Luck!!!