What's this supposed to connect to??
 

Any idea how this is meant to connect and if it's the cause of any of my problems? Hopefully you can see the disconnected cable in the photo.

This car is new to me so I don't know if this has been like this for a while or if it's new.

Probably unrelated information :
Engine light has recently come on (Fixd can't read or clear the code)
Front brakes don't work... I assume it's the calipers and they will be replaced.
If rear brakes lock up the antilock system kicks in and I have no brakes at all.
It's a 4 wheel drive version 2000 ram 2500 without front abs
https://cimg2.ibsrv.net/gimg/dodgefo...48cc066f37.jpg

Transmission is overheating and I'll replace the coolant line with the ball valve.

Thanks for any help!

That's just your breather. Supposed to clip up to the frame. Wouldn't cause any codes or problems

Thanks Keith!

What motor?

I'm pretty sure it's a 5.9 v8
magnum

Yes, the photo of the hose is of the vent for the rear axle assembly. You can affix it back up on the frame and all would be well.

As for the codes, you can clear them by disconnecting the battery terminals, waiting a few minutes and re-connect them.

As for the brake issues, given the age of the truck, I'd check your metal brake lines carefully. They are prone to rust over the years and develop pinhole leaks, especially the brake line going to the rear brakes behind the fuel tank along the frame rail. Is the brake fluid in your master cylinder low?

There doesn't appear to be a brake fluid leak as the reserve remains full. I've got replacement flexible brake lines for the fronts that I'll change with the calipers.
I'll check the metal brake lines and replace if necessary too.
I cleared the code that way and it came back a few days later...

You can get the code(s) by doing the ignition key process and reading the check engine light flashes to read the codes. PERSONALLY, i find it easier to use a cheap OBD-2 scan tool that you can pickup most anywhere for under $20 or by going to an AutoZone or an Advance Auto store, where they will read your codes with a scanner for free.

I bought a reader but it's not reading it. I'll find out how to do the flashes and see how I go or go into autozone.

Check your fuses to make sure that a fuse isn't blown that provides power to your diagnostic port with regard to your code reader not working.