| Author |
Message |
Verell Boaen (Verell)
Intermediate Member
Username: Verell
Post Number: 1065
Registered: 5-2001
| | Posted on Saturday, August 09, 2003 - 11:17 pm: | |
The strap goes up & is bolted to one of the frame box members. I seem to remember that it's the box that goes across the top of the front of the luggage area. Anyway, it's a proper frame ground.
The metal outer barrel of the antenna is what shold be grounded.
BTW, there should also be a ground wire or strap between the motor & the metal outer barrel. On one of my antennas, the strap went from a motor mounting screw head to one of the screws that clamps the outer barrel to the drive body. Unfortunately, that clamp screw was a tad too short & wasn't grounding the motor! Talk about a problem driving you nuts! Only found it by accident. |
dave handa (Davehanda)
Intermediate Member
Username: Davehanda
Post Number: 1526
Registered: 5-2001
| | Posted on Wednesday, August 06, 2003 - 11:48 pm: | |
On the 328 antenna, the braided ground strap is attached directly to the metal shaft of the antenna just above the black plastic motor housing, NOT the mounting bolts from below. Where this ground strap goes back to, I have no idea, as I did not trace it. All I know is that replacing my antenna fixed the terrible static I was getting on AM. |
Verell Boaen (Verell)
Member
Username: Verell
Post Number: 986
Registered: 5-2001
| | Posted on Monday, July 21, 2003 - 8:56 pm: | |
BTW, the brass insert in the bottom of the plastic motor case that's used for bracing the antenna IS NOT grounded to the antenna.
Here's something to try:
With the engine off, see if turning on the vent fans degrades reception. If it degrades, then noise is coming into the radio via it's power lead. Especially if AM is very noisey & FM is vy quiet. In this case, get a 20A radio noise flter from Radio Shack & put it in series with the radio's power lead. Make sure the filter's ground wire is as short as possible & connects to something thats tied back to the frame. (Assuming that the radio doesn't draw more than 20A (few will - 20a @ 12V = 240 Watts RMS!! ). If it draws more than 20A, it's time to go to an automotive audio specialty shop for a vy high powered filter! |
DGS (Dgs)
Junior Member
Username: Dgs
Post Number: 200
Registered: 5-2003
| | Posted on Monday, July 21, 2003 - 3:25 am: | |
The 328 still uses a tube frame, I believe, rather than a "unibody". The ground should, ideally, go to a frame component which is electrically common to the frame that the engine grounds to.
The primary concern, though, is that there is as little resistance as possible between the antenna ground plane and the stereo's ground.
This may be as much an issue with the stereo's ground as with the antenna's. |
dave handa (Davehanda)
Intermediate Member
Username: Davehanda
Post Number: 1347
Registered: 5-2001
| | Posted on Sunday, July 20, 2003 - 8:39 pm: | |
The ground can go anywhere there is clean, metal to metal contact with the chassis. With most antennas, the antenna is grounded by the very aspect of it being bolted to the body. Often times with motorized antennas there is an additional ground wire that is attached to something convenient. On the 328 there is a braided ground strap that attaches to the antenna, which with the antenna bolted to the body, completes the ground connection. |
john roberts (Jr328gtb)
New member
Username: Jr328gtb
Post Number: 48
Registered: 5-2003
| | Posted on Sunday, July 20, 2003 - 8:24 pm: | |
at the risk of being an idiot, where on the fender does the ground get mounted? do you have a picture of yours
thanks
john |
dave handa (Davehanda)
Intermediate Member
Username: Davehanda
Post Number: 1328
Registered: 5-2001
| | Posted on Saturday, July 19, 2003 - 11:03 am: | |
john,
Cheap test. Go to auto supply store, buy a $10 fixed antenna, and plug it in from the trunk, ground it out and start the car and see what happens. If that solves it, go and buy a new antenna with the link I provided. Your existing antenna must be grounded, the ground is completed when it is mounted to the fender! |
john roberts (Jr328gtb)
New member
Username: Jr328gtb
Post Number: 46
Registered: 5-2003
| | Posted on Saturday, July 19, 2003 - 10:38 am: | |
DGS
i have only had the car for a few months but it is not as simple as the antenna not being raised.
i have run a few different tests where the only changed variable is the car running.
with the car off and antenna raised, I get good reception of stations and the seek function picks up stations rather easily.
with the car running and antenna raised, i get poor reception of the same stations and the seek does not work well at all.
maybe a ground problem???
any more thoughts |
DGS (Dgs)
Junior Member
Username: Dgs
Post Number: 190
Registered: 5-2003
| | Posted on Saturday, July 19, 2003 - 7:16 am: | |
It can depend on your reception area. It's a matter of signal/noise ratio. If you have strong radio signals around, the engine noise may be insignificant. But if the signal isn't all that strong, the noise may become a problem.
If the radio works with the engine off but has "very poor" reception with the engine running, then either the signal is too low or the noise is too high.
The signal could be too low because of a bad antenna (or one not raised), or a deteriorated antenna cable, or (in my case) a big honkin' hill between me and the local radio stations.
The noise can be too high because of a poor ground between the stereo and the antenna, or because of engine ignition noise. Or from stray signals leaking from a local industrial plant. (My garage door opener used to have problems before HP/Compac took over and revamped the DEC chip plant a couple of blocks over -- which may be just a coincidence as there are lots of other tech businesses around here.)
The only parts the individual car owner can tweak are the antenna, wires, ground, and the car's own ignition noise. But it's not something easy for the shadetree mechanic to diagnose except by trial and error. |
dave handa (Davehanda)
Intermediate Member
Username: Davehanda
Post Number: 1319
Registered: 5-2001
| | Posted on Saturday, July 19, 2003 - 12:31 am: | |
DGS, I don't think it matters on the 328. I have non resistor extenders (factory), and non resistor plugs(factory specified), and no interference on the radio. The problem I had was directly attributed to a defective (bad) Bosch antenna. |
DGS (Dgs)
Junior Member
Username: Dgs
Post Number: 189
Registered: 5-2003
| | Posted on Friday, July 18, 2003 - 10:00 pm: | |
How long have you had the car? I know this may sound dumb, but I had my 328 for a couple of weeks before I realized that I had to manually raise the antenna using the console switch. I was used to automatic ones. [chagrin]
If it works with the engine not running, you might need to check the grounding on your antenna and radio, or check if you have resistor plugs or extenders. (See thread on extenders) |
dave handa (Davehanda)
Intermediate Member
Username: Davehanda
Post Number: 1314
Registered: 5-2001
| | Posted on Friday, July 18, 2003 - 11:40 am: | |
I had a similar problem, it was cured by replacing the antenna (simple proceedure). The only hard part was finding a suitable replacement. I went to www.antennaworld.com and found a semi-automatic antenna with a black mast,black cap and tip. The original antenna is chrome mast, black cap and tip (and Bosch no longer makes it either). NOS when found is about $500! |
john roberts (Jr328gtb)
New member
Username: Jr328gtb
Post Number: 44
Registered: 5-2003
| | Posted on Friday, July 18, 2003 - 11:10 am: | |
my 1989 328 has an alpine radio/cd player installed. It gets very poor radio reception while driving...antenna appears hooked up correctly etc.
i noticed today that it gets decent radio reception while turned off and parked in the garage (rain today)
any thoughts??? |