2004 T5 C70 aerial issue ( not the normal issue ) Topic is solved

[NathansC70]

The schematic above is from Mitchell. I think Mitchell got it wrong.

This from Volvo TP3943292 which, according to Volvo Tech Info, Cover 2000 S70, 2000 V70 and 2000 - 2004 C70.
Looks like Scot850's suggestion is the first port of call.
You might try pulling the SC901 out, disconnect the harness, for voltage on Power Antenna motor wire.


2019-04-14 (5).png

2019-04-14 (6).png

Ok novice auto electrician here, pulled out stereo wire fine no damage and plugged in. The stereo pin connected to the wire, when read with a multimeter between it and ground reads -4.4v. The wire with car on reads 12.3v, if the wire unplugged has 12v isn’t that the supply going into the stereo? Checked fuse 16 (30amp and is fine) also all main fuses look ok the big 50amp ones.

Not sure which relay to check, or which wires to check between the aerial end. Due to the control box on the aerial. Also doesn’t the car shut the aerial off if you open the boot?? Help

[RickHaleParker]

Look at the Volvo schematic. The signal wire from the radio to Antenna is marked Blu-Y (Blue-Yellow).

Colors
BK, Sb = Black
BN = Brown
BU, BL, Blu = Blue
GN = Green
GY, GR = Gray
LGN = Light Green
OG, OR = Orange
PK, P = Pink
RD, R = Red
VT, VO = Violet
WH, W = White
YE, Y = Yellow

[NathansC70]

The schematic above is from Mitchell. I think Mitchell got it wrong.

This from Volvo TP3943292 which, according to Volvo Tech Info, Cover 2000 S70, 2000 V70 and 2000 - 2004 C70.
Looks like Scot850's suggestion is the first port of call.
You might try pulling the SC901 out, disconnect the harness, for voltage on Power Antenna motor wire.


2019-04-14 (5).png

2019-04-14 (6).png

ok there are two wires coming from the motor into c/bc which im assuming is the pub on the aerial itself. one wire through pin 3 is bl-w turning into bl-y to the stereo ok getting to my point. the other in pin 4 goes to 23/422? and 31/12? then via a sb wire goes to the cd changer? i removed my cd changer years ago should this be the issue does it need another voltage through cd changer or a ground?

[RickHaleParker]

Pin 4 on Connector C/BC, 23/433 and 31/12 is the ground for the Antenna motor and the CD changer. That symbol at 31/12 is a ground symbol.

Pin A-3 on the back of the radio would be the first to investigate. That is make sure the radio is putting out the signal to raise the Antenna. If so make sure the signal is getting to the Antenna motor. This signal is also at pin 3 on Connector C/BC.

Put your probe on C/BC pin 3 then pin A-3 on the back of the radio, turn the radio on and off see if it changes. Report the measurements.

The Antenna motor needs three things to operate. Power, Ground and Command.
You need to determine which of the three are missing.

[NathansC70]

ok many thanks to all those who helped and for the wiring diagrams. after pulling out the stereo and the yatour iPod connector and reinstalling the no longer present cd changer connector the aerial started working. i thought that can't have been the issue but maybe this lead is creating a better ground and making the aerial operate. so i re installed the yatour only for the aerial to stop working. what i then noticed is the issue all along. one of the cables from the main connector on the rear of the stereo would not stay in the plastic block and was pushing itself out when i reconnected it. once this cable was reconnected properly the aerial now works ever time. the blue and yellow wire! so check that first! 3 years and finally its sorted. time to sell the car now lol thanks again to all