Need help to rewire antenna for 308/328

I hope I don't get roasted for cross posting this but I didn't get any response in the 308/328/Mondial section so maybe I'll have more luck here.

I know this is an old chestnut on this board but I have been through the archives and couldn't find the help I needed.

I've got a generic automatic antenna I'd like to convert to a semi-automatic type but not using the diode method. I've followed as much advice as I could from this post by Wolftalk:

http://www.ferrarichat.com/forum/showpost.php?p=135084253&postcount=9

Unfortunately, I think this antenna is slightly different from that one, not sure whether it's to do with that curious resistor and capacitor on the bit that shuts the power off (illustrated). I've tried connecting the red and blue wires straight from the motor to the ferrari wires and had no joy (shouldn't that have done something at least?).

Can anyone have a look at the diagram I've scribbled together and maybe suggest a way to make this work? I'd be very grateful. Many thanks.
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I can help you out, but I need to know more.

1. What is this generic antenna? What did the instruction manual say about the wires, and the polarity of the voltages applied across the terminal, in order to get the thing to move up, and or down?

2. What are the 3 terminals?

3. The resistor and cap, are those things you added? What for?

4. What do you want to do ? Wire it to the antenna swith so that you can manually make it go up and down, or wire it to the radio so it goes up and down as you turn on or off the radio?

 

Thanks for your reply. I don't know nothing about electronics so I'm not entirely sure but:

It's just a generic 'fully automatic' antenna. It had a relay in it which had a positive and negative wires coming out of it. I want to convert it to a 'semi-automatic' so I chopped out the unnecessary relay.

Do you mean the thing with the three things on it? As far as I can tell that's a thing that stops the power when the antenna is either all the way up or down but I'm not sure.

I didn't add those. I don't know what they're for.

yes, just like the original one.

Any help very much appreciated, thanks.

 

Overall picture of automatic operation:

The radio must have an 'antenna' connection which requests the antenna to raise.
A relay at the antenna does the thinking.
The antenna will have 3 wires: ground, +12v, and radio connection.

If you still want involvement of the original antenna switch, I withdraw.
If your meaning of semi-automatic is elsewise, I withdraw.
Hate posting without help but think need agreement on terms first.

 

Thanks for your reply. The antenna is currently fully automatic, I would like to convert it to semi-automatic so I can raise and lower it buy using the switch on the centre console.

It is generally believed that this conversion is trivial but I can't get it to work despite following advice posted on the forum over the many years leading me to believe this 'fully automatic' antenna is slightly different from the norm. I'm sure there's a simple solution. Hopefully someone who understands electronics can look at my diagram and recommend what I need to do.

 

I got it now.

The 3 wires are as below:

yellow: power, +12V, you connect it to +12V, non switched, always on.
white: ground, you connect it to ground.
Blue: is the ignition (or the radio antenna signal) that is 12v when you turn the radio on.

In order for you to wire it so that you can control it with the Ferrari Antenna switch, you need to wire the blue wire to the middle terminal of the switch on the console,

The Ferrari switch is a 3 terminal device, one is +12V, one is Ground, and the middle terminal is a wire to the antenna (like that blue wire in your picture). When you press on the console, it will either apply 12V to signal the motor to turn in one direction raising the antenna until you let go of the switch and the motor stops. You apply ground to the same pin to tell the motor to turn the other direction until you let go of that switch.

Good luck.

 

The 308 and 328 antenna switches are different. The 328 is a double pole switch, that switches both plus and ground to two antenna motor terminals. In one position, it applies power and ground to the two antenna motor terminals. In the other position, it reverses the connections. In the center position, nothing is connected.

The 308 switch is single pole. As I understood it, the 308 antenna was a center tap motor. Apply power to one terminal, and it raises, apply power to the other terminal and it lowers. The center tap is ground. The switch connects power to one of two wires, going to the two operating terminals of the antenna motor. (If the 308 was a plus or ground switch as described, where would the antenna get power when the switch is ground?)

On your "automatic" antenna, it was the relay that controlled up or down movement, by reversing the polarity across the motor. The built in switch will be a notch gizmo -- the white wire will be connected except when fully up (or down) and the yellow wire will be connected except when fully down (or up) -- you'd have to check which is which. Are you sure that's a resistor inline with the capacitor, and not a diode?

If you're not worried about the automatic limit stop, you could ignore the switch, and run to the red and blue wires. Power to blue, ground to red would either raise or lower the antenna while applied. Power to red, ground to blue would be the opposite motion. The yellow and white wires both connect to the red wire, except one is disconnected when the antenna is fully raised, and the other is disconnected when the antenna is fully lowered. (As in wolftalk's post, if you wire the white and yellow wires together, you'll have a permanent connection to the red wire regardless of antenna position.)

Presuming the yellow wire is the "fully down" one, then if you connect power to the yellow wire and ground to the blue one, the motor will turn when it's not fully down. (If it tries to extend, then it would have to be power to the blue, and ground to the yellow to get it to retract until it's down.)
If power to yellow / blue to ground causes the antenna to fully retract, then to exend the antenna, you'd apply power to the blue wire and ground to the white.

So you have to figure out whether the white or yellow disconnects at fully up or down, and figure which way the motor moves with power on the blue (and ground on the red via the switch). Then you need a relay to switch the terminals around depending on whether you want the antenna to raise or lower.

On a 328, the double pole switch swaps power and ground for you, and you could hook one pole to the blue and the other to both the yellow and white wires. But with a 308, the single pole switch only redirects power, and you need a relay to move ground around for you, if you don't have an original type center tap antenna motor.
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Very excellent and very detailed explanation.

Decampos, if you truly have a fully automatic antenna like you said. These are $59.95 antenna one buys from Kragen (I did), then you only need 3 terminals. One to 12V, one to Ground, and the 3rd for control.

Get a Digital Multimeter, pull up the switch from the console, figure out which pin has its voltage switched from 0V to 12V in one position, and back to 0V in the other direction (and no connect in the center position). Then wire your control wire to that. Push one direction to make it go up, the other to make it go down.

If you have some other antennas with different wires and relays, etc.. then disregard everything I say here. Follow what the poster above says to do. He is the pro, I am a hack.

 

Thanks for taking the time to help out guys. Really helpful stuff. I'll put this thread to bed with a dummy's guide to this modification when I've finished it.

 

Trying to install a new antenna into my 87 328.

I bought a new antenna that has two leads, red and blue. Also has a black ground wire.

On the car side, there are two white wires with red stripes, both feeding the antenna power.

Are these wires equal? Does it matter which one is connected to the two antenna wires? I suspect one is up, one is down.

Another issue, I'm having a hard time getting the thing to actually work, and I suspect it's a bad ground. There is a grounding strap coming from the car. I need to test this for good ground. I have a digital multi-meter; can anybody suggest a method to test this strap wire for ground? I suppose I can find another chassis ground source nearby, maybe the screw stud coming out of the wheel well intended for mounting the base of the antenna.

Any advice appreciated.

Greg
87 328 GTB

 

Your 328 (like mine) is wired for a semi automatic antenna in a different way than the early 308.

The 2 wires (white/red) have 12V across in one position, and 12V in reverse polarity in the other position. It works only with a semi automatic antenna that also expect 12V in one way, and reverse polarity in the other direction.

I don't know how your new antenna works so I can't say. What did the signal names say on the box?

 

The antenna I bought is a Metra Antenna Works, Fully-automatic AM/FM antenna.

Apparently the red wire is to be connected to a constant hot (unswitched) 12V source, and the blue wire is to be connected to the blue radio wire, signaling the antenna to raise.

Not sure if this is gonna work with my 328, with the console-mounted antenna switch.

The car ( I bought it a couple months ago) has a nice Alpine radio, I suspect from about 8-10 years ago. I don't see a blue wire run from it to the antenna compartment in rear.

The guy at Woody's Custom Shop on Ebay said this would work with my 328, here's the link:

http://www.ebay.com/itm/NEW-Replacement-Option-Bosch-Autojet-AM-FM-Electric-Power-Radio-Antenna-/360422980034?pt=Motors_Car_Truck_Parts_Accessories&fits=Year%3A1985%7CMake%3AFerrari%7CModel%3A308+GTB%7CSubmodel%3AQuattrovalvole&vxp=mtr&hash=item53eae239c2#ht_1707wt_919

During testing today with my multi-meter, I was able to get power to the unit and make the mast move, not sure what I did--I think I created a ground with the negative probe while touching one of the connectors...Got dark and couldn't recreate it..

??


Any ideas out there?

Greg

PS--the Ebay ad shows that this unit will not work with the 328, but WILL with the 308--BUT the business owner assured me it would. I assume this is down to the differences in the console antenna switch.

 

Here is an idea.

Pull up the antenna switch, remove the connector, and some how wire the 12V from one of the input wires one of the 2 output wires so that that red/white wire always have 12V. A jumper wire is what i would do.

Go back to the antenna, connect the now 12V wire to the antenna Red wire. Ground is chassis and easy to find.

Your Alpine has at leas 1 blue wire. You need to find that wire and run it to the area where the antenna switch is, and connect it to the remaining red/white wire. Back at the antenna, connect that remaining red/white wire to the blue antenna wire.

This will work, except that you no longer use the antenna switch on the console to raise it. You still can leave it in the console.

 

Thanks Yelcab. Alternatively, is it possible for me to leave the switch wiring alone, and simply connect the antenna to the existing setup in a certain way? I know I can get the mast to move, I found it briefly yesterday but couldn't do it again. I was enlisting the help of a friend to depress the switch as I tried different connections and grounds.

I guess I'd prefer to have the antenna controlled manually from the console switch.

Greg

 

Did the manual that you received with the antenna describe anything about the signal needed on the blue wire or other wiring details? If it needs to be a constant signal (like "when the blue wire is at +12V = the antenna stays in the up position" or "when the blue wire is at ground = the antenna stays in the up position"), by using a cluster of relays (in a self-latching way) you can convert the momentary signals from the stock 328 antenna switch to a constant signal that would put "X" on the blue wire when the 328 switch is momentarily moved to the up position and keep it "X" after the 328 switch is released to center; and then put "Y" on the blue wire when the 328 switch is momentarily moved to the down position; and keep it "Y" after the 328 switch is released to center -- but this assumes the blue wire needs a constant signal and not just a pulse.

Alternatively, do you have a model number for the Metra antenna you received?

 

Steve, I appreciate you responding here, as always. If anybody can figure this out, you can!

The Metra model is: 44-PW22

The instructions offer 2 wiring schemes, one for radios with a switched antenna wire (blue) and one for radios without the switched blue wire. For this type, it instructs the user to remove the radio from the dash, remove the top or back cover and solder a blue wire to the radio volume control/power switch. Then run that wire to the blue wire at the antenna. Seems complicated!!

I suspect my fairly recent Alpine head unit has a blue wire, just maybe wasn't run to the back of the car, for the obvious logistical reasons. I suppose I could pull the radio and have a look. I sure wish there was a simple way to connect this thing without having to do all the suggested gyrations--plus I prefer having manual control of the mast with the console switch.

I did use the DMM to confirm that the 2 car-side white/red (they appear identical) wires receive 12V when the console switch is activated. One for up, one for down. Neither appears to have a constant hot 12V. Not sure why an antenna would need a constant hot 12V wire anyway; only when you depress the switch would be preferred, no?

So, the magic question again is, how to connect the 2 car-side wires to the blue and red wires of the antenna. ???

Puzzled in Houston,
Greg
87 328

Thanks for any help!

 

The schematic on page two of your installation instructions confirms that:

red wire = +12 always
when blue wire = +12V = antenna up and working
when blue wire = 0V = antenna down

This is not possible (because, as you noted, the signals coming from the stock 328 aerial switch are only momentary; whereas, your Metra antenna needs constant signals on the red and blue wire). You will need to either:

1. Run a new, always +12V, wire to the red wire; and run a new wire that is +12V when the radio is "on", and 0V when the radio is off, to the blue wire (as you noted, your radio may already have such a wire) -- the mast will be up whenever the radio is on and down whenever the radio is off), or

2. Add a cluster of relays between the red/white wires in the trunk from the stock 328 switch and the red and blue wires; and add a new wire to bring always +12V to these relays -- when the 328 switch is moved to the up position and immediately released, the antenna will go to the up position and stay there; when the 328 switch is moved to the down position and immediately released, the antenna will go to the down position and stay there. NOTE: Although this is very similar to how the stock 328 system works, it is not identical as the stock antenna only moves while the 328 switch is actuated and the stock antenna can be stopped in a mid-position (but your new antenna can never be stopped in a mid-position). If you'd like a schematic for this modification (using two ...113 relays and one ...101 relay) let me know.

 

Wow, I was afraid of this reality. Makes sense, Steve.

I'd like to see a diagram of the relay cluster you reference, if you have a moment.

When I get time this week, I'll pull the head unit out and have a look for the magical blue wire.

Any advice on where to possibly find a nearby constant +12V source near the antenna mount location??

Thanks!
Greg

 

If you have a US version 328, the (relatively) large wire connected to terminal 30 of the protection relay is connected directly to the battery so that would be a good place in that area IMO (but also add a fuse in series to whatever you add since that line going to terminal 30 is completely unfused).

A euro version 328 will be more difficult.

I'll post a proposed schematic tonight or tomorrow.

 

Get the blue wire from the dash into the console, then pick any of the old radio antenna control wires to "be the blue wire" back to the antenna location.

 

Greg

Out of curiosity, why don't you buy a Hirada semi-automatic antenna like I did and it just pop it in? It seems that if you have a fully automatic antenna, you should use it that way, no ?

 

Steve,
Pardon my ignorance, where is the protection relay? Must be in the engine or trunk compartment?

BigTex,
Good idea, will be easier than running a wire all the way back to the trunk. Wait, didn't Steve say the blue wire must be constant +12V hot? The momentary console switch won't provide that. (?) Or do you mean, bypass the switch and have the constant blue wire direct from radio into antenna (with a splice at the switch)? That would make sense.

Yelcab,
I suppose I could return this antenna and get the right one, but I first wanted to see if there was a feasible way to use this fully-automatic one. Jury's still out!

Greg

 

Your radio has a 'blue antenna wire" it provides the power when the unit is on.

Yes, disconnect one of the existing switch wires from console to antenna and use IT as the new "blue wire".....

So using that, the antenna will go up and down as required.

 

Yes, it's the relay with the built-in 10A fuse mounted on the rear trunk floor panel with the injection ECU (if you have a US version 328 -- you have not confirmed/denied this).

 

I think it is US car Steve, it came from West Texas.....