Head unit not working

[PrOxIMPURE]

Hey guys,

Just randomly after using the radio this morning, my head unit has stopped working and will not power on anymore. I have a pioneer head unit installed and I have tried reinstalling my stock stereo and that too has no power when car is on and off. I have tried changing fuse number 42 but still no luck. Does anyone know what the problem could be or has anyone experienced something similar?

Thanks

[pinchies]

I guess check the other fuses, or measure the voltage on the supply pins at the radio head unit connectors with a multimeter when the accessory power is on.
Edit: some headunits have a fuse on the back of them, perhaps check those as well. Once you find the problem, then it will be easier to fix and prevent from reoccurring.

From the diagram below, looks like you'll want to check the voltage on pins 7 & 8 on the black connector.

[PrOxIMPURE]

I guess check the other fuses, or measure the voltage on the supply pins at the radio head unit connectors with a multimeter when the accessory power is on.
Edit: some headunits have a fuse on the back of them, perhaps check those as well. Once you find the problem, then it will be easier to fix and prevent from reoccurring.

From the diagram below, looks like you'll want to check the voltage on pins 7 & 8 on the black connector.

[ATTACH=CONFIG]5923[/ATTACH]

Thanks for the information, I think there might be a problem with pins 7 or 8 but if that is the case how would I resolve this issue? I don't think there is much, if any power going through these pins into the head unit.

[pinchies]

Just check em and see what the voltage is. If there is no voltage at all (most likely I think if both h/u are not working!) its 99% certain to be a fuse somewhere else, but if there is a voltage then its something else probably to do with another wire, and you would need to find someone else who knows more about it than I do.

Your battery hasn't run flat recently or anything like that?

[PrOxIMPURE]

Just check em and see what the voltage is. If there is no voltage at all (most likely I think if both h/u are not working!) its 99% certain to be a fuse somewhere else, but if there is a voltage then its something else probably to do with another wire, and you would need to find someone else who knows more about it than I do.

Your battery hasn't run flat recently or anything like that?

No my battery hasn't run flat, everything else inside seems to work fine except the head unit. Hopefully the problem lies within another fuse.

Thanks anyway

[pinchies]

I'm too busy at the moment with uni, or I'd offer to help you out personally -- if not sorted in a few weeks, let me know. If you don't have a multimeter, I would highly recommend getting one, as they are handy for all electrical stuff, will save you time with this kind of thing, fairly cheap, and easy to learn how to use.

[PrOxIMPURE]

I'm too busy at the moment with uni, or I'd offer to help you out personally -- if not sorted in a few weeks, let me know. If you don't have a multimeter, I would highly recommend getting one, as they are handy for all electrical stuff, will save you time with this kind of thing, fairly cheap, and easy to learn how to use.

I'm in a similar position with year 12 exams coming up but thanks for the offer. I did just recently purchase a multimeter but hasn't delivered yet but will be sure to check out the pins and fuses as soon as it arrives.

[pinchies]

Ok! Well good luck with school, and once the meter arrives can walk you through what to do.

[MCiN7]

Try fuse 42 (25amp) (panel of the right of the dash)

http://www.mikegabriel.net/vw/bentley/mk4/9%20Electrical%20System/97%20Wiring%20Diagrams,%20Fuses%20and%20Relays/97%2001-15%20General.pdf

If you already have the head unit pulled out, plug it back in and bridge the red & yellow wires (this will confirm the fuse is toast if the unit switches on)

[PrOxIMPURE]

Try fuse 42 (25amp) (panel of the right of the dash)

http://www.mikegabriel.net/vw/bentley/mk4/9%20Electrical%20System/97%20Wiring%20Diagrams,%20Fuses%20and%20Relays/97%2001-15%20General.pdf

If you already have the head unit pulled out, plug it back in and bridge the red & yellow wires (this will confirm the fuse is toast if the unit switches on)

I have tried replacing fuse 42 and the head unit will still not power on as mentioned above

I have tried changing fuse number 42 but still no luck.

[PrOxIMPURE]

Head unit not working

I guess check the other fuses, or measure the voltage on the supply pins at the radio head unit connectors with a multimeter when the accessory power is on.
Edit: some headunits have a fuse on the back of them, perhaps check those as well. Once you find the problem, then it will be easier to fix and prevent from reoccurring.

From the diagram below, looks like you'll want to check the voltage on pins 7 & 8 on the black connector.

[ATTACH=CONFIG]5923[/ATTACH]

Just received the multimeter and checked pins 7&8 and there is no power going through at all when car is on and off. What would this mean and does anyone know how to fix this?

Thanks

[pinchies]

Head unit not working

Just received the multimeter and checked pins 7&8 and there is no power going through at all when car is on and off. What would this mean and does anyone know how to fix this?

Thanks

For a start, it means that the head units are probably ok. Bad news is that it's time for everyone's favourite game... Checking fuses. Check #10, #37 and #42 (most likely but you already replaced it).

[PrOxIMPURE]

For a start, it means that the head units are probably ok. Bad news is that it's time for everyone's favourite game... Checking fuses. Check #10, #37 and #42 (most likely but you already replaced it).

Just cheeked fuses 10, 37 and 42 which are all fine. Any other ideas or suggestions?

[pinchies]

Ok, so the next thing to do is to check there is power getting to those fuses, and then tracing along till you find where the problem is. On the car, the metal body is grounded to the negative battery terminal, so you can measure the voltage at any point with the multimeter. Set the multimeter to voltage, and touch one end of the probe to the car shell, and one end to the fuse you are trying to measure. Check the voltages on each of the three fuses listed, and see what you get. If the reading is zero volts on the 42 fuse then the problem is probably between the fuse box and the battery. If it is 12v, the the problem is between fuse and audio area.

[tek199]

Check if you are using the oem adapter cable from the iso connector. My alpine unit was using a different adapter cable.

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