Cub Cadet Volunteer fuel pump relay

[jrobert]

Hi, My 2008 Cub Cadet Volunteer with 31 hp Kohler Aegis EFI engine will not start. When the key is turned the fuel pump does not run to pressurize the fuel system. Talked to the local dealer and he would start at the fuel pump relay. I cannot find a complete electrical schematic for this unit but downloaded the service manual from Kohler. There is battery voltage at relay terminal #30 with the key off as there should be. With the key on there is only about 2 volts at terminal #85, it should have battery voltage according to the manual.
Anyone have a similar problem or know where I can find the wiring diagram?
thanks

 

[SpudHauler]

Here is a typical wiring diagram for a relay.

Make sure you have 12 volts on the input 87, and that can be 12 volts with the key on or off depending how they wired it.

When key ON, 85 will have 12 volts to energize the magnets to make the contacts work.

Bad ground on 86 can cause relay switch to fail.

Pin 87 is sometimes not used at all.

Then 30, the output, will have 12 volts to run what ever it is hooked to.

If you put a jumper wire between 87 and 30 the fuel pump should run because you've just by passed the relay.

If all that checks out its possible the fuel pump is bad.

Hope this helps.

 

[jrobert]

Thanks, I will look at this later in the week. When reading the service manual Cub Cadet may be set up differently.

 

[SpudHauler]

J,
Just understand that all relays work the same. The magnet is powered by 85 with ground on the 86 terminal. Power 85 and with a good ground on 86 the relay should click or make contact between 87 and 30. So when the magnet works, putting power on 87 should in turn put out power on 30.

So in you case if the key is ON and any other safety switches set right, that may be a problem as well, you should be getting 12 volts to the relay magnet and it should snap the contacts shut. And with 12 volts on 87 you should see 12 volts on 30. Which would mean the relay is working.

Hope this helps.