General Pioneer Head Unit Blown Fuse ?

[theoneandonly]

I have a Pioneer radio ( in a Rapido) that has worked since conversion and has a seperate power switch. It has just given up. The 2 "radio fuses" F46, F39 show continuity. Ive recently been in the Battery box so just in case looked there for an inline fuse, no luck.
Any ideas other than dismantle front end and search for a cable to follow.
PS 2017 model
ideas on how to dismantle front end if required

 

[HughJampton]

It's fairly common for Pioneer units to have a fuse on the back of the unit. Reference to the manual or posting the model number should advise on that.

Whatever, I suspect the unit will have to be removed, using whatever extraction keys it needs.

 

[theoneandonly]

Thanks @HughJampton h
mANUAL IS for AVH-X5800dab OR 3800 OR 2800.
there is no number physicaly on front.
There is no reference to a fuse on back so its time to rip it all apart and look

 

[HughJampton]

I've only looked at the 5800DAB version, but the images show a 10A fuse on the rear of the body.

Reference this page here:

PIONEER AVH X5800DAB | ESupplyLine

esupplyline.com

 

[theoneandonly]

Thanks youre a star.

 

[theoneandonly]

Rear of mine is different no fuse vissible. To right of radio is a switch the feed is 10.4v it dissapears behind the fusebox. Th sb is 12.6v lb 13.4v too dark to play anymore.

 

[HughJampton]

I think you may find the fuse is under the RH of the main wired connector block. It coincides with the picture/link I've already posted (which doesn't have the connector in place), and I can see what looks like a red 10A fuse peaking out there.

Absolutely no guarantee that's the problem, but fuses are always worth checking.

 

[HughJampton]

...though if the feed is really 10.4V, it's below the minimum spec of 10.8V..

 

[Anthony489]

Hi

If you pull out the DC multiway connector, the fuse should be visible. I think you can just see the red edge of it in your photo, underneath the paddle to stop you changing it whilst things are still plugged in !

However, you then need to find out the reason it has blown. One possibility is that a loudspeaker line has shorted, which would cause the unit to draw more than usual current when playing music. Should be obvious when you listen (once it is going again). These things tend to draw a baseline current all the time, plus a varying amount which goes up as you increase the playback volume.

I'm a bit puzzled by your feed of 10.4 volts. That sounds rather low if it is something connected to the vehicle or leisure battery. Sometimes electronic power supplies are designed to cope with a range of input voltages. However, if the voltage goes down they draw more current to compensate. If the voltage is too low, this may have been just enough to cause it to draw more than the fuse could take.

Principal Standard Colours on the Head Unit

Red Main 12 volt feed, normally from an ignition switched supply
Yellow Permanent 12 volt feed, to keep memories alive
Black Ground

Blue/White Power output for aerial amplifiers etc

On page 5 of the operating manual it describes how to reset the microprocessor, if you find that the unit is powered but not responding or not responding properly.

 

[LandyAndy]

Fuse???

 

[theoneandonly]

Thanks gents will have a look tomorrow

 

[theoneandonly]

well that's been fun.
the radio fuse was there and intact.
Turn on ignition no lights or central display engine starts.
The red wire to switch read 11 v switched it on 0V.
Look at fusebox and diagram i'm reading fuse values don't tally
need to check 2017 x290.
One 10A fuse melted slightly 32 or 93 Rear fog light
Just been out to check something before posting and central display came on "open door"
Been using info from fuse box info.
now pissing it down or would go and check voltage at battery (would a dead batter show these symtoms but still start?)

 

[HughJampton]

I think you need to understand how the radio was wired by Rapido, and what the purpose of the switch is.

The switch may be a simple on/off switch allowing for the fact that the Pioneer units seem to be designed to be used with power feeds that have an "ACC" position (lacking in the Ducato) allowing use with the ignition off. In this case, the main power is not taken from the conventional (ignition-controlled) radio feed, but from another permanent source (somewhere at the back of the fuse-box?) so the state of the fusebox "radio" fuse might be irrelevant.. The switch is fitted because the Pioneer units draw significant current even when switched off at the unit fascia (if powered by a permanent rather than ignition-switched feed).

Alternatively, it may (effectively) be a changeover switch, allowing powering from the leisure battery(ies) when on site when the ignition is off.

I am certainly aware of a number of Rapido conversions that were wired from the factory in the latter manner. AIUI, it was conventional under these circumstances to fit blocking diodes in the (now two) main feeds, to avoid any "back-feed" when the switch was on. (It isn't really a conventional changeover, but functions in that manner). In this case the feed from the vehicle battery would likely be via the conventional ignition feed, and a separate switched feed added from the leisure battery (which could be fused anywhere!). That arrangement is something akin to this example.

edited to add: Fuse 32 would, I think, be a permanent live, so might be the connection point?

 

[Anthony489]

Hi

I attach a diagram for the standard Radio setup in the earlier X250 models. Yours won't be the same, but it will give you an idea of the Fiat way of doing things. Sometimes MH converters will modify the power feed arrangements so that you can listen without needing the ignition on, but I have no information on your specific vehicle.

For the later X290 models, the info I have on fuses is this:

Ducato 2015 to 2019

F36 10 Amp Radio (permanent), climate control, alarm, tachograph, battery disconnecting control unit, Webasto auxiliary heater timer (+battery).

F49 5 Amp Radio (ignition switched), steering wheel controls, central control panel, left control panel, auxiliary panel, battery disconnecting control unit (+key), Parking sensor control unit,

F93 7.5 Amp Right Fog Light

 

[theoneandonly]

Thanks gents I did wonder why there was not 12V at the switch, the radio only works with switch on iresspective of ignition.
the instrument cluster gong dark (dead?) is now my main concern.

 

[Anthony489]

Hi

Looking at page 157 of the 2019 user manual, Fuse F37 supplies the instrument panel, the brake lights control etc.

If you mean the illumination of the instrument panel, I believe that is a separate feed and will depend on whether the external lights are on, unless it has been reprogrammed to be on all the time.

 

[theoneandonly]

Instrument cluster sorted.
Engine started RED started @11v Down to 5v green 0v switch on or off..
It doesnt look particularly easy to get at the rear of fuse box . Might be easier to run new lines to the lesiure battry

 

[Crossingkeeper]

well that's been fun.
the radio fuse was there and intact.
Turn on ignition no lights or central display engine starts.
The red wire to switch read 11 v switched it on 0V.
Look at fusebox and diagram i'm reading fuse values don't tally
need to check 2017 x290.
One 10A fuse melted slightly 32 or 93 Rear fog light
Just been out to check something before posting and central display came on "open door"
Been using info from fuse box info.
now pissing it down or would go and check voltage at battery (would a dead batter show these symtoms but still start?)

11v on the supply dropping to 0v when you put a load (the radio) on suggests a poor connection somewhere in the supply line (especially as the supply voltage is 'only' 11v rather than battery voltage!)

Easier said than found, I know, but you could test the theory by running an independent (fused) 12v supply to the switch/radio.

 

[Anthony489]

Hi

It does sound as though you have a high resistance connection somewhere, either loose or corroded.

Before you pull the fuse unit to pieces, these units are generally reliable unless they have had a lot of water into them. The connections are made by metal stampings with few joints to go wrong. What happens more often is that corrosion builds up between a blade fuse and its springy holder contacts.

Sometimes just pulling the fuse out and putting it back a few times is enough to scrape off the film of corrosion.

If you have a voltmeter, note that many fuses have small gaps in the plastic insulation to expose the metal connections each end. You can connect to these with fine probes to check the voltage whilst the fuses are in circuit.

Also worth checking the appearance of the pins in the multiway connectors and their mating sockets - anything that isn't clean and bright should be investigated.

 

[theoneandonly]

Thanks all
i have wired it to work only on the LB. (all hunky dorey)
i have no intention of ripping the fuse box apart.
While its apart i may reroute some of my camera feeds.