When I use the 4CM, my amps volume controls won't work.

[ElectricRelig]

I have my Helix plugged in to a Fender Deluxe.

 

Guitar - Guitar In - Send 1 - Amp Input - Power Amp Out - Return 1 - Mono 1/4" - Power Amp In

 

But the volume controls on my amp don't seem to work anymore. Could someone explain this?

[rd2rk]

Is there a send/return/loop block in the preset?

[DarthHollis]

Do you have on the FX loop path #1 in the Helix on?  That's problem number one.

 

What most people don't understand is the that master volume on your amp controls the FX send level.  There is no level for the FX return.  This may not be all amps but most of the ones I have dealt with.  

 

Tip of the day:  I keep the master volumes for the two channels of my amp higher than I would probably ever need and then I use the Helix master volume as my overall volume.  When I use a preamp in the Helix and bypass the preamp on my amp (by turning off the FX loop #1 in Helix) I can set the preamp level to match the amp.  

[HonestOpinion]

I have my Helix plugged in to a Fender Deluxe.

 

Guitar - Guitar In - Send 1 - Amp Input - Power Amp Out - Return 1 - Mono 1/4" - Power Amp In

 

But the volume controls on my amp don't seem to work anymore. Could someone explain this?

 

Your cabling for the 4CM connections may not be correct. I can't tell from your path above what exactly is plugged into what. The connections you used are more easily understood when described in pairs and it should be clear which side of the pairs is the Helix and which is the amp. Nothing should be plugged into your amp's "Power Amp Out" other than the amp's speaker but perhaps you were referring to the Helix's 1/4 output?  

 

Here is a good video for 4CM setup with Helix. Keep in mind the alternate terminology used for amp FX loops used in this video and apply it appropriately to your Fender.

 

You should be able to use separate Send and Return Blocks (as demonstrated in the first video) rather than the FX Loop block preferred in this video.