How to test a P80 sedan radio mast/motor?

Post by **scot850** » 18 Feb 2023, 16:58

Ok all you electrical marvels, how do I go about testing a Volvo mast off the car? The connector has 3 wires. 2 red and one black. One of the reds I think is red/something.

I remember testing mast years ago but no longer have a sedan. I thought it as a simple case of a ground, one power line for up and one for down. I just tried that and a big nothing using a 12V power supply. Strage thing is the power supply did showed 12V but 0A? Not sure why that is.

I have no idea if the unit is good and can take it apart to clean a verify the mast is good and not seized.

Thanks,

Neil.

Post by **MoVolvos** » 18 Feb 2023, 17:07

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If my memory serves me right I replaced the mast on the 98 S70 T5. Here is Robert on another forum.
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https://volvoforums.com/forum/volvo-s70 ... nna-43304/

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Post by **BEJinFbk** » 18 Feb 2023, 18:06

The antenna receives constant power via fuse 16 on a Green/Red lead.
Ground should always be present on the Black lead.
A 12 volt signal from the HU on the Blue/White lead raises it.
Take that 12 volts away and it will retract.

If you have different colors, it probably isn't an original unit,
but the principle of operation should be the same.

Post by **scot850** » 18 Feb 2023, 19:06

That is great help except my wires are different at the antenna end. Pictures below:

: Antenna wiring colors - P80 S70; PXL_20230219_021244500.jpg (267.39 KiB) Viewed 268 times

This is a genuine Volvo unit based on the picture with the motor cover below:

: Volvo ID on P80 antenna; PXL_20230219_021249949.jpg (345.17 KiB) Viewed 268 times

I believe the colors you may be talking about are the ones for the wiring harness from the head unit? I believe the wire from there is blue/white if I recall. You can see it here in this picture at the harness at the back of the head unit

: Wiring harness at head unit; PXL_20201130_003712717.jpg (187.86 KiB) Viewed 268 times

Looking at your info, I would see it as:

I need constant 12V on the Red/Green wire and a ground on the black, but then a switched power signal to the solid Red wire? Does that sound about right? I can easily do that with my power supply for my audio test kit and run 2 switched power wires. Switching the Red/Green on first and then the Red which should then power the antenna to raise. Switching the Red wire power off it should lower. Seems simple enough............!!

Many thanks!

Neil.

Post by **BEJinFbk** » 19 Feb 2023, 14:09

Just be careful with that thing...
You could put your eye out!
.

: RedRyder Kit.png (54.7 KiB) Viewed 253 times

Post by **abscate** » 19 Feb 2023, 14:39

My diagram shows power up on green red , ground on Black , and control signal on Blue White

Post by **scot850** » 19 Feb 2023, 16:22

The blue-white wire possibly goes to the ignition switch. The main thing is I know the Green.red wire is the constant power and black is the ground. So that hopefully means the solid Red is the switch wire.

I'll try that and see what happens, what could possibly go wrong..................!

Neil.

Post by **scot850** » 19 Feb 2023, 18:56

Well it worked. Well sort of. I used some crocodile clips and wires and connected to my switches and when the red/green wire was switched on Nada, nothing. Then turned on the Red wire and the motor hummed but not much happened. Switched it back off and it hummed again. So I am assuming either the mast is stuck or the plastic toothed drive cord has stripped a few teeth. I have a spare MTC mast so I can install that.

I should have cut the other part of the connector off as it would be easier to work with to make up a connector wire system.

Thanks for the help guys.

Post by **scot850** » 26 Feb 2023, 16:12

As I mentioned in my other thread on re-building the power antenna mast (As used on S70's, 850 sedans and possibly more) I have tried to figure out why when I am powering the antenna, it seems to work in reverse to what I expected.

viewtopic.php?t=101833

Still trying to figure it out, but at least realised from Abscate's wiring diagram above, that the GR (green)/R (red) wire is a constant power line which runs directly to the antenna.

The BL (blue)/ W (white) wire runs from the back of the head unit and not from the ignition switch as I assumed.

The only other wire remaining is the SB (black) wire which is the ground wire.

Now that I have an antenna extension for the wireless signal connection, I will get back to this tomorrow as I want to connect the Blue/white wire from the head unit directly to the antenna without another switch and see what happens when I use the on/off switch on the head unit to raise/lower the mast.

I'll update accordingly as I also intend to see what happens with the 2 x $8 power antennas I got on clearance from Canadian tire operate and if they do in the same way. They have the same part numbers but are physically different. One has a black control boa mounted to the mast similar to the OE antenna, but the other one does not. Curious to see if it works in the same way.

Neil.

Post by **BEJinFbk** » 26 Feb 2023, 16:32

Different HUs signal the antenna to raise in several ways.
Some raise the antenna as soon as the HU is powered up,
Some only send 12 volts when the tuner is selected.
I've never had a P80 with a power antenna, but
it'll probably be one of this two sequences.

If you're curious, you could put a meter
on the power antenna lead from the HU.