Pin in back of receiver broke off

First off, using a Ground post driven into the soil is important. The best ground post procedure is to SLANT a 6 or 8 foot rod into the soil at an angle (not directly down). The angle allows for a greater ground surface and is more effective. If a Ground rod is cut off because it cannot be driven deep into the soil; this defeats the need to ground electronic or other devices.
12G wire is OK for an antenna if 8 or 10 are not available. Copper is best, but aluminum will work. The Grounding bock is attached to the mast, usually near where the antenna if affixed to the mast. Simply drill a small hole into the Mast section using the block as your guide. Using a hex driver and small hex screws, tighten the block to the mast. Good contact is necessary, so tighten all attachments. I suggest getting Rubber Boots or Covers to protect the connectors on the block from corrosion. The reason I attach blocks to the mast is to ground the Mast first and Antenna second. Not a critical feature. You may also use petro-jelly to cover the nuts, bolts, and screws to prevent corrosion or binding.

Hello, is the broken pin on the back of the unit or is it on the antenna cable plug? If it is on the unit and not the cable, you would most likely need to replace the connector that is attached to the PC board inside, which extends through the back of the case. This would require knowledge of soldering / desoldering pc boards, etc. and would be best performed by a "bench technician". There are no "user replaceable" plugs available.

Your antenna pin solder joint on your dock connector is bad. I've seen this problem a lot (I buy returned sirius radios, fix them, and resell them). The antenna connector is on the right of the dock connector. It has 1 n-shaped pin (connected to 2 pads on the PCB), and 1 middle pin. The middle pin's solder joint has cracked, and needs to be resoldered. You can use any soldering iron to do it, just use flux and be careful not to bridge the pins.

The remote control door lock receiver (rcdlr) antenna and receiver are the most likely cause of your problem. If you remove the A pillar molding on the drivers side you should see the antenna attached with a push pin against the paint. You could try attaching the antenna ground to the pillar by cleaning the paint off and using a real screw to attach the ground.

The other fix is having the rcdlr, antenna, and transmitters replaced which will cost you some money. This bulletin number will help if the dealership will print it for you. 07-08-52-001C

one of 3 things, either your antenna is not insight of a skies view to receive the signal, or its wire is broken at the antenna, but if you remove the antenna connection frequently it pulls the center wire out of the connection on the end that fits into the radio when its plugged in push on the conductor at the back of the plug and see if this helps,alos if connection is loose take a safety pin and carefully between the outer plug case ans the ground fingers around the center pin push these in so you get a better ground, and lastly try another substitute antenna, I have re-soldered my connections numerous times to fix this issue, delphi doesn't make a very rugged product, good luck

Are you missing the center pin, by chance (which often snaps if the plug isn't lined up correctly or if you wiggle the lead to connect or disconnect)?
I fixed mine by inserting a 1.5CM piece of very thin but stiff copper wire into the dimple. You may have to 'coax' it a bit with needle nose pliers.

Crat

facing the back of the 7940 the top left corner is pin 16 the top right corner is pin 9. The bottom left is pin 8 and the bottom right is pin 1. Only a few of the 16 pins are used due to this unit only having pre-outs, no internal amplifier on this unit. Pin 1 red (ignition), Pin 2 pink/black (interrupt), Pin 3 orange (Illumination), Pin 8 black (ground), Pin 9 blue (power antenna), Pin 10 blue/white (remote turn on), Pin 16 yellow (battery).

how do I fix this?

If you are looking at the external connection end with it in a "V" position, on the right - the upper one is green & the lower one is red. On the left - the upper one is yellow & the lower one is black (or the big bunch of copper wires). Be sure you are reconnecting an exact pin set up - an s-video is not the same (unfortunately). If you found a replacement antenna or a correct replacement part, please let me know where. I have to repair mine too.

Best idea would be to get that son back on the job - he should remember where he de-soldered it from!!!