The coax cable from my mast head antenna to the connection at the base of the mast has water inside it. I need to replace the cable and need to know how to ensure a water tight connection when I install the new fittings.

Important! Please give copies to all your VW Technicians C 91--99--07 E 1999 Volkswagen of America, Inc. 1 Subject: Model(s): Group: Number: Date: AM Radio, Poor Reception 1999, 2000 91 99--07 New Golf, New Jetta, Aug. 2, 1999 New Beetle, Passat Condition AM reception is poor. May be caused by: ? An incorrect antenna mast installed for the antenna base equipped with the vehicle ? Poor ground at the antenna base or radio ? Poor battery ground to chassis or engine ? Poor antenna cable connection at Radio ? Corrosion at the antenna coaxial connectors at radio or antenna Service Vehicles are equipped with either a Bosch or a Clarion antenna base mounted on the roof and (for shipping purposes) the appropriate matching mast is located in the luggage compartment. If radio antenna masts are removed from vehicles and stored until vehicles are sold, there is a chance that an incorrect mast can be installed at the time of delivery. Note: Mismatched antenna mast and base will cause poor AM radio reception. The antenna base and mast can be identified visually as follows: (Cont. on Page 2)91-A260 requires gloss finish antenna mast 57mm 49mm Bosch 91-A261 requires matte finish antenna mast 61mm 41mm Clarion 91-A262 Technical Bulletin Important! Please give copies to all your VW Technicians C 91--99--07 E 1999 Volkswagen of America, Inc. 2 Bosch antenna ? Base (although oval) is more circular in shape (approx. 57mm x 49mm). ? Made in Germany stamped on underside of base. ? Two screws on underside of base are unpainted. ? Requires gloss finish antenna mast. Clarion antenna ? Base is more oval in shape than Bosch (approx. 61mm x 41mm). ? Two screws on underside of base are painted. ? Requires matte finish antenna mast. If antenna mast matches the antenna base correctly: -- Check antenna coaxial cable connections --arrows-- for corrosion and clean if necessary (DO NOT apply stabilant). Passat coaxial cable connection for radio is under the carpet on right side of tunnel near shifter. -- Ensure that coaxial cable is firmly seated in radio (Passat cable connection, see previous step). -- Check ground at the antenna below roof Nut --4-- (torque = 7+1 Nm) must firmly secure antenna to roof). (Cont. on Page 3)Technical Bulletin Important! Please give copies to all your VW Technicians C 91--99--07 E 1999 Volkswagen of America, Inc. 3 -- Check ground for radio behind radio on cross member (On Passat models as of Nov. 1998 beginning VIN: XE285000 ground for radio is on right side of center tunnel). -- Check engine compartment ground, left side, below battery tray; frombattery GND to body. -- Check engine/transmission ground on transmission, near engine block. -- If all grounds and antenna mast are OK. -- Replace antenna and coaxial cable assembly

Mercedes preferred supplier of aerial masts is Hirschmann. There is a connector to the top of the box a coax aerial connection to the mast root, an earth lead strap and a bolted bracket to the base. The aerial mast exits through the car skin in a rubber fitted sleeve. You say that you can hear the motor running but that the mast refuses to emerge. The beauty of Hirschmann is that their motor drive antenna assemblies are readily disassembled (and reassembled). You will need to take the mast assembly out of the vehicle; disconnect the wiring plug socket, remove the bracket bolt, earth strap and unscrew the coax cable connector. Pull the mast firmly down and out of the body work sleeve. The outer aerial mast is driven up by a toothed plastic flexible inner rod normally stored in a coil within the motor assembly. Remove the torx screw in the middle of the rounded end and separate the two halves. At the top is the electric motor set horizontally which drives a rubber belt to a helical drive immediately below it lying parallel. If this belt is broken this would give rise to the motor running but not engaging . The helical drive engages with the edge of the storage drum feeding out and retrieving the coiled rod to raise and lower the antenna. If the helical drive or the drum edge has missing teeth then the aerial cannot function. All these components can be be bought from Hirschmann spares or through your Mercedes dealer.

How do I install a new antenna on my GMC 05 2500 Sierra. I have to replace the base because it broke off. I've taken the dash off. But cannot seem to fish wire through the firewall.

Try a new antenna temporarily--just hold the mast base in your hand. Water can enter the antenna cable from outside which shorts it out. Hope this helps!

1. Disconnect negative side of battery.
2. Wait at least 2-minutes to de-energize the airbag system
3. Remove the glove box from the dash.
4. There will be a coax cable towards the top of the opening. Disconnect the antenna cable lead.
5. Remove the right kick trim panel. There should be no screws just clips.
6. Loosen the rubber grommet insulator from the door hinge area. This is a rubber accordian style guard for wires located between the "A" pillar and the door.
7. Pull the antenna cable out of the dash area to the hinge area.
8. Jack up the front right of the vehicle. Support with Jack Stands. Do not use only the Jack! Use the jack as a back-up in case of Jack Stand failure.
9. Remove the right front tire.
10. Remove the right front wheel housing splash shield. There should be 3-push type retainers and one 10 mm bolt below the bumper.
11. Slide the plastic cover (on the base) up on the antenna mast.
12. Use a open end wrench to unscrew the antenna mast at the base and remove the antenna mast.
13. Remove the plastic cap from the base nut on the base and remove the base nut.
14. From underneath the fender: pull down the antenna base. And pull the cable towards you - out from the door hinge area into the fender area.
Good Luck! Installation is reverse of above.
If this helped or you need clarification or additional help: let me know at fixya.com

Remove old Antenna

1. Activate the antenna switch to the up position.
2. Using the wrench or needle-nose pliers, loosen and remove the original retaining nut on the base of the antenna mast.
   
3. Gain access to the underside of the area of the trunk where the antenna is located.
   
4. Remove the bracket or brace that is below the hole and holding the antenna in place.
   
5. Remove the mast.
   
6. Find the motor that controls the antenna mast. Generally, power antennas will have a constant 12-volt lead and a ground lead. The ground lead will be grounded to the panel next to the motor.
   
7. Remove the ground lead from the panel.
   
8. Pull out the antenna coaxial cable.
   
9. Unplug the coaxial from the extension coaxial cable.
   
10. Remove the original antenna coaxial cable. Note the route the cable follows.
    

Install new Antenna

1. Inspect the fender area where the antenna mast will be mounted for rust.
   
2. Clean the area before installing the new antenna.
   
3. Plug the new antenna coaxial cable to the extension coaxial cable.
   
4. Plug the new antenna's coaxial cable into the radio's chassis antenna jack if there is no extension coaxial cable. Tie or tape the string you put on the extension cable to the new antenna coaxial cable. This assures that the 2 cables stay together as you route them to the antenna mount in the fender.
   
5. Connect the power lead of the antenna to the power antenna lead on the radio.
   
6. Connect the 12-volt constant lead to the antenna to a 12-volt source or to the ignition switch.
   
7. Direct the new antenna cable via the same route followed by the original antenna cable on up to the hole in the fender in which the mast will be mounted.
   
8. Ground the ground lead from the motor to a clean metal surface on the metal panel near the mount.
   
9. Insert the mast into the hole. Face the serrated side of the plastic cable on the bottom of the mast toward the motor side. The plastic cable can be inserted freely to about 12 inches and will stop.
   
10. Turn on antenna switch to down position until the plastic cable goes down and catches into the gear mechanism of the drum housing. If the plastic cable does not gear into the mechanism, twist the cable slightly until the cable contacts into the gear mechanism while the motor is in operation.
    
11. Stop the motor after the cable goes into the housing 12 to 25 inches.
    
12. Secure the bracket or strap to the bottom of the antenna mast and to the metal fender.
    
13. Replace the retainer nut to the base of the antenna mast and secure tightly.
    
14. Replace the panel that covers the antenna mount area.
    

Man...you have no idea what a job this is! Go to a car stereo shop and pay somebody to do it!
Good Luck

Give these instructions a shot. Might be too generic but might be enough to get you going. Removing Original Antenna
1. Step 1 Activate the antenna switch to the up position.
   
2. Step 2 Using the wrench or needle-nose pliers, loosen and remove the original retaining nut on the base of the antenna mast.
   
3. Step 3 Gain access to the underside of the area where the antenna is located.
   
4. Step 4 Remove the bracket or brace that is below the hole and holding the antenna in place.
   
5. Step 5 Remove the mast.
   
6. Step 6 Find the motor that controls the antenna mast. Generally, power antennas will have a constant 12-volt lead and a ground lead. The ground lead will be grounded to the panel next to the motor.
   
7. Step 7 Remove the ground lead from the panel.
   
8. Step 8 Pull out the antenna coaxial cable.
   
9. Step 9 Unplug the coaxial from the extension coaxial cable.
   
10. Step 10 Remove the original antenna coaxial cable. Note the route the cable follows.
    Installing the New Power Antenna
11. Step 1 Inspect the fender area where the antenna mast will be mounted for rust.
    
12. Step 2 Clean the area before installing the new antenna.
    
13. Step 3 Plug the new antenna coaxial cable to the extension coaxial cable. (On some General Motors and Ford cars you may need an adapter to mate the 2 cables together. Car audio retail stores sell such an adapter.)
    
14. Step 4 Plug the new antenna's coaxial cable into the radio's chassis antenna jack if there is no extension coaxial cable. Tie or tape the string you put on the extension cable to the new antenna coaxial cable. This assures that the 2 cables stay together as you route them to the antenna mount in the fender.
    
15. Step 5 Connect the power lead of the antenna to the power antenna lead on the radio.
    
16. Step 6 Connect the 12-volt constant lead to the antenna to a 12-volt source or to the ignition switch.
    
17. Step 7 Direct the new antenna cable via the same route followed by the original antenna cable on up to the hole in the fender in which the mast will be mounted.
    
18. Step 8 Ground the ground lead from the motor to a clean metal surface on the metal panel near the mount.
    
19. Step 9 Insert the mast into the hole. Face the serrated side of the plastic cable on the bottom of the mast toward the motor side. The plastic cable can be inserted freely to about 12 inches and will stop.
    
20. Step 10 Turn on antenna switch to down position until the plastic cable goes down and catches into the gear mechanism of the drum housing. If the plastic cable does not gear into the mechanism, twist the cable slightly until the cable contacts into the gear mechanism while the motor is in operation.
    
21. Step 11 Stop the motor after the cable goes into the housing 12 to 25 inches.
    
22. Step 12 Secure the bracket or strap to the bottom of the antenna mast and to the metal fender.
    
23. Step 13 Replace the retainer nut to the base of the antenna mast and secure tightly.
    
24. Step 14 Replace the panel that covers the antenna mount area.
    

Make sure the broken mast is in the same state as the replacement mast (most likely fully retracted). There will probably be two connections on the unit, motor power and radio signal. Examine the latches on the motor power connector to see how the work; most likely you have to squeeze in a pair of plastic tabs while pulling on the connector (don't pull on the wires!) in order to unlock the connector.

Check the gasket around the antenna base. If it is hardened, and the replacement antenna does not have a good gasket with it, apply an automotive-grade body sealant or caulk to keep water from getting into the car body. (Many of those I've seen use a rubber base without a separate gasket; often this is hardened and will not seal without help once it's been removed.)

If the radio cable has a screw-on connector, put it on snugly finger tight. Cranking it on with a wrench may break the terminal inside (I've seen a number of TV tuners destroyed this way). However, most car antenna connections I've seen resemble over-sized phono plugs and jacks - push on and pull off. Often there is a protective sleeve or boot over the connector; you may have to pull it back along the cable first. Again, pull on the connector, not the cable. If that doesn't work, it may be a bayonet-style connector that you have to push in and rotate a quarter-turn counter-clockwise, then pull it off (I don't recall ever seeing that on an antenna, but it's mechanically possible).

You access the ariel via the left hand wheel arch.
1. Remove left wheel mud guard. It is held in with a bunch of press studs which can be difficult to remove. I found pulling on the plastic mud guard whilst turning the screw helped.
2. unbolt the electric ariel assembly. There is an earth strap that needs to be unscrewed as well.
You should be able to get the ariel out far enough to work on it.
3. Remove chrome plated nut to top end of mast tube.
4. With great anger and force, remove the dead ariel and drive cable from the mast.
It's difficult to get the mast to work unless it's earthed properly.
5. Get you hand inside the wall and remove the ariel face plate. Swear if you have to.
6. Put the ariel mast assembly back into the wall and hook it all up minus the new ariel.
7. Switch your radio on, then put the new ariel into the mast. Gears facing the rear of the car. Switch the radio off, it should retract. If not you may need to push it in a little further.
8. Remove the ariel mast again and slip the chrome nut to top end of mast tube and tighten securely.
9. Ask the spouse to close up whilst you have a beer.