Nobody

I just installed a XFM receiver, its a FM modulated unit so I play the XFM stations through my factory radio..thats all well and good- the prob is the antenna...XFM has its own so I would like to retract the factory one when the XFM is playing, but being a FM modulated unit the antenna extends even though I dont need it.
I'm sure there is a way to remotely retract the antenna (and extend) I'm under the impression that the relay sends a momentary 12V pulse to the antenna motor to retract or extend-or it may interrupt a ground..I'm not sure..witch lead on the relay should I tap into to achieve this?

Relay schmatic

yellowspeedracer

well your link doesn't work.

the antenna should go up when the 12v power antenna wire off the radio is hot. this happens anytime the radio is using the tuner (am/fm) so if your xm thing is fm modulated, you're using the fm tuner to hear the xm stations. therefore, the antenna will be up when you're using the xm unit.

i think you could hook up a relay so that when the xm unit is on then it interupts the signal going to the antenna. then the antenna would go down. you'd need to find a wire that's hot when the xm thing is turned on. perhaps if the modulating unit is seperate from the display there would be a power wire that would do that for you...i don't know.

you could also just hook up a seperate switch that would interrupt the signal going to the antenna.

Mystickal

Putting a switch in the remote power line would definitely be much easier than using a relay. Sure, you'd have to manually flick the switch to lower/raise your antenna rather than doing it happening automatically, but now that you have XM, how often are you going to listen to local stations anyway?

Besides, if you try the relay route, most likely you're going to have to open up the XM unit and tap into something there.

Just my $.02

~Bill

Nobody

This is my goal..I'm not sure if the relay sends a turn on pulse (like a sub amp) or supplies the 12V to it..I could start 'testing' leads on the relay but im afraid of frying it.

Maybe this will help

Mystickal

Find the wire that is going to pin 8 on your diagram. Cut it. Route the new ends to either side of a switch.

Then, when that switch is closed, the circuit will act as normal (antenna goes up when radio is on, goes down when radio is off).

When the switch is open, it will interrupt the signal going to the relay, and the relay will *think that the radio is not operating, then antenna will go down.

The above is assuming that the antenna is up when your radio is playing and goes down when your tape deck is playing.

It doesn't send a 'pulse' - it produces a constant 12V, low amperage signal.

~Bill

Nobody

Definitely! - I don't mind the antenna up on the hiway..but on the trails ill rip it off, and it would be nice to have the XM rockin while wheelin!

Nobody

CUTTING

I feel like Ed Harris in the Abyss when he was cutting the wires to the nuke!

Duffdog

you have to be careful about that, because the factory antenna out of the radio has 2 wires which make it stay up--when you put in an aftermarket deck, the harness has a jumper that goes from one wire to the other to make the ant. stay up. or you could stop being cheap and install an aftermarket radio with a direct connection which would give you real cd-quality sound instead of FM and raise and lower the antenna automatically.

T

Mystickal

Yeah, from the diagram that Nobody posted it looks like the antenna relies on wire 7 to see that the headunit is powered up and wire 8 to see that the radio section is on. So if he interrupts the signal on wire 8 then the antenna will see +12V on wire 7 (headunit on) but 0V on wire 8 (radio off) and thus the antenna should not raise.

If the relay logic is OR'd then he'd need to interrupt both, if the relay logic is AND'd then he can interrupt either one. Based on the way it operates though, there cannot be OR logic present otherwise the antenna would stay up while listening to tapes.

~Bill

Nobody

Success!!

But cutting #8 dident work - the antenna still went up and down on its own - However taping into #1 did the trick! the switchwhen turned on raises the antenna - I can switch it off and it stays up-butkeeping it on and selecting either CD or TAPE lowers the antenna at that point I can switch it off select TUNER and the antenna stays down- just a quick flip of the switch at any time and the antenna raises!

By the way if anyone installs this mod- when you blow the fuse on lead #1 replace the fuse in the engine compartment labled 'Dome' (took me a 1/2 hour to run that down!)


Thanks for the replys Mystickal and Duffdog...gave me the encourgment to dive in and start cuttin

Mystickal

Congratulations

That's strange. Your picture shows that it should produce 12V when the radio is ON and the cassette is OFF, but show nothing when if the radio is OFF or the cassette is ON, or if the ignition is in LOCK. That would seem to then be the sense wire that determines if the antenna needs to be extended or not. Unless there's something behind it in the circuit, though I can't imagine what. . .

Ahhh, master power interruptus. Wire 1 must be the constant power that is routed to the motor when the relay closes. If you turn the switch while the antenna is in the process or raising or lowering does it stop where it's at?

~Bill

Nobody

Yes it does

Thought for a minute(make that 9/16 of a sec) there that it wasent going to compleatly extend when I fliped the switch back on after 1/2 a sec it extended

Mystickal

One of those heart-stopping moments when you think to yourself "#@$&, I should have just taken this thing in and paid someone instead of #@$&-ing with it myself"

Followed quickly by the "I AM THE #@$&-ING MAN!" when it does actually work.

Sorry about the bad advice on wire #8 - there must be some other logic in there that kept it from reacting properly. It'd be interesting to find out exactly what other logic is there (and why!) but at least you've got the results you wanted.

On a final note - make sure that the switch you are using has a decent rating. I don't know how much current the power antenna motor draws (it really shouldn't be TOO much, but some switches can't handle very much at all - you can probably check by noting the rating on the fuse in the engine compartment that you had to replace) but if you're on the power going to the motor just make sure the switch can handle that much current.

~Bill

Nobody

No prob - I was just as willing to cut #8 as you were to suggest it-just a quick solderless connector... and it did kick in a few more brain cells to try #1 - constant power....hmmm

Used a 10amp 125V swich.