Antenna Base Upgrade

I've searched high and low, but haven't been able to find a definitive answer. Has anyone replaced the basic stock antenna base (1J0035501F) with the combo antenna base (1J0035501G)? Car is a MKIV Jetta TDI Sedan.
I need to add a GPS antenna for an aftermarket head unit, and would prefer to not mount something on the dash. Does anyone know specifically what kind of connector is on the GPS antenna lead on the combo base (1J0035501G) so that I can also get the correct cable and adapter(s)?
To be clear, I'm not looking to add satellite radio, or TV, or anything else. I'm JUST looking to use GPS navigation and AM/FM; I would be leaving the third lead on the combo base disconnected. Thanks in advance, I apologize if this has been asked and answered before.

I haven't used that antenna so I can't answer your question directly. When I upgraded to an Alpine head unit a few years ago, I installed a MK5 antenna base on my MK4 Jetta. It easily conforms to the roof. I might have a photo somewhere. There are a few different versions of the MK5 antenna base with 2, 3 or 4 wires. I used the 4-wire version which supports AM/FM, GPS, GSM and SiriusXM. The part number is 5N0035501B. The connector for GPS is a FAKRA connector and depending on your head unit, it may plug directly into the port on the back or you may need a FAKRA-to-GT5 connector if it is an Alpine head unit. While some resellers label 1J0035501G as GPS, I don't think that is correct. I am more than 50% sure that is the GSM antenna for the cell phone integration.

The wires are color coded. You might be able to use the 2 or 3-wire one instead, I'd need to look up the colors again. This is what it looks like mounted on a MK4 Jetta:

The colors are:

Grey = AM/FM
Green = Satellite Radio
Blue = GPS
Red = GSM

The 2-wire base 5N0035501A is grey and green (AM/FM and SiriusXM) so no GPS. The 3-wire version 5N0035501D is grey, red and blue (AM/FM, GSM and GPS) so that might be the one to do what you want to do.

Side note, from what I understand, the GSM antenna isn't really usable anyway because it's optimized for 800MHz only I think.

Thank you benmarks! You've answered my question perfectly; I think the 3 wire is the way I need to go. Follow ups: Will I need to get the "stubby" antenna, or will the original "whip" style fit? Is there any signal loss with the AM/FM, and how significant? Will I need to purchase a gasket, or is that typically included?

You can re-use your original antenna.
I got a stubby Sharan-style antenna purely for cosmetic reasons.
I haven't noticed any signal loss and I don't see why there would be.
The gasket comes with the antenna base.

Awesome, it looks great, BTW. Thanks again!

ereeves said:

Will I need to get the "stubby" antenna, or will the original "whip" style fit?

Click to expand...

There are at least 2 different thread sizes.
I found this when I changed the base on my 03 wagon.
Got a good used one off a wreck.
Base looked new.

wonneber said:

There are at least 2 different thread sizes.
I found this when I changed the base on my 03 wagon.
Got a good used one off a wreck.
Base looked new.

Click to expand...

My research shows within the MKIV & B5 models, the masts come with 2 different thread sizes. The larger should be for/from a car with OnStar.
I had hoped to use the OnStar style base & mast to support an old style MFD, but couldn’t find an easy way to connect/adapt the connections in the mast.

As benmarks suggests using MKV or similar are the easier way to go.

"I need to add a GPS antenna for an aftermarket head unit, and would prefer to not mount something on the dash. "

-Another option, remove gauges, and mount GPS antenna UNDER dash (on the round crash bar, with zip ties). I did that, GREAT reception, even on cloudy days, super easy to do! I added a "shark fin" to cover the factory base, just for looks, but I never use FM anyhow...WAY to much commercials, Pandora only now.

VincenzaV
Does the crash bar continue behind the radio?
Don't know if my 2014 Jetta is similar but I would like to try the GPS antenna under the dash.

I already have Delirious radio in the factory radio so I think that antenna should plug right into my interface.

Yes, in my MK4, it is structural and goes all the way across the car. I don't think you can see it as easy from behind the radio, but all I needed to do was unscrew two screws to get to the area behind the gauges (and unclip the gauges). It was right there. Plenty of length with my GPS antenna wire, I just looped it and zip tied the excess.

Thanks VincenzaV
I'll swap the radio in my 2014 Jetta in the near future.
Will check if I see the bar then.
Don't know if I'm going to replace the speaker at the same time.

Here's a pic wonnerbear, again I already had the dash completely out for the blend door repair, but you can easily access this crash bar via two screws on the MKIV chassis. If you look closely, my magnetic GPG antenna slide down slightly on the crash bar (I did zip tie it once, as a preventative measure). When I noticed it doing the blend door repair, I added an additional skinny zip tie to the center of the antenna to prevent this in the future. Either way, even with it sliding down, I NEVER had any reception problems.

Don't think I ever noticed that bar in mine or didn't realize what it was.
Only had the radio out and the dash display once.
Thanks.

I have the OEM Triplex antenna on two of my MK4s paired up with the OEM MFD navi. The correct cable for the GPS is FME female to SMB female right angle. I think I got 12ft for the Jetta, and 15ft for my R32. I'm not 100% sure on the lengths, I just remember I had to replace the AM/FM cable on one of them, and I ordered the GPS cable in the same length as the old AM/FM cable.