HELP...radio wont work

Hi guys,i need help..
Took out the original radio today and tried fitting a pionner unit from another car,but that wouldnt even turn on so i gave up with it.
Then i plugged in the original radio into the original wiring loom and now that wont turn on at all.
I tested the power supply with a test light and its there but the radio wont turn on.
Everything is back to original,why wont it even display any error codes?
Thanks,Joe

did u test constant and accessory wires? u may have only checked constant which has power without ignition

check all fuses (engine bay and passenger side)

Elsewhere in these forums there can be found some info about the stereo and the instrument panel sharing an earth. It's also reportedly somewhat flaky.

What I'd try first: check that the instrument cluster is all functional including the backlighting.

Second, I'd use a multimeter and test for connectivity between the chassis of the radio (a usual earth/negative) and the body of the vehicle. If there's no connectivity, it has to be the earthing of the radio. If there's a partial connection, remove the car's antenna plug from the back of the radio and read it again. If the reading is gone, you've definitely got an earth problem.

Thanks for your suggestions,NISMO4X4 you were correct.
The fuse under the bonnet(which i didnt check) "AUDIO" was blown,thats probably why the other radio didnt work either.
I will have to try it again later.
This forum is so helpfull,i cant say how much i enjoy it on here and appreciate all the helpfull advice..
Thanks again,Joe

pleasure mate. just be careful cutting the accessory and constant..any shorts will blow a fuse.

Whats the best way to go about it?
disconnect the battery positive?

Negative's easier to remove. Or just pull the fuse.

thanks Old.Tony i will give that a go

Elsewhere in these forums there can be found some info about the stereo and the instrument panel sharing an earth. It's also reportedly somewhat flaky.

What I'd try first: check that the instrument cluster is all functional including the backlighting.

Second, I'd use a multimeter and test for connectivity between the chassis of the radio (a usual earth/negative) and the body of the vehicle. If there's no connectivity, it has to be the earthing of the radio. If there's a partial connection, remove the car's antenna plug from the back of the radio and read it again. If the reading is gone, you've definitely got an earth problem.
i have same problem with my radio, it like shorted out the other day when i was putting in my new stereo, but no fuses appear to be broken, but now my speedo doesnt work!!!! wht do u recomend i do a: if its earthing off the radio, b: if i take the arial out and i have an earthing problem??

Welcome to the forum, Bowen.

Do your instrument lights come on with your park/headlights?

It is possible that the speedo has failed, if your instruments and the lighting is all working. It might have had a surge.

If the whole cluster is behaving oddly, chances are you've removed the earth from the panel. I'd start with testing the resistance from your stereo's case to the car's chassis first, and make sure that it's zero Ohms. If not, you may have dislodged its earth.

There's a couple of things to think about, anyway. Good luck with it!

Why is there also a fuse under the bonnet for the radio as well as the in cab one?

thanx buddy i appreciate the advice, i also suspect the earth, so im thinking i may have to trace it back... ive noticed that i cant create a circuit with the head unit wires eg. acc and pwr connect to constant, and earth to earth equals head unit shows it has power but wont turn on. and i wired it straight to the battery after to make sure it wasnt the head unit, but it fired up straight away when i connnected it straight to thebattery. its really odd cause i have dash lights eg. 4x4 , handbrake, seatbelt. but i have no back light for the speedo or the speedo itself?? any ideas on where the earth cable for all those is connected?? cheers mate

I don't have a D22 to go out and check, I have the D40 - I just ducked in here because I remembered a common reason for these failures.

Have you tried connecting the radio chassis to the car's body directly and seeing what happens? It should not have any problems doing that. Test the voltage between the two first. Too high a voltage and you could cause problems and that's when I'd be seeing an auto electrician.

Put your multimeter in 50V scale, black lead on body, red lead on radio chassis and it should not move the needle. If it does, it should not rise to battery voltage - a small voltage indicates the stereo is not connected to earth properly.

This might fix your dash lights as well.

dunno what the deal is with the actual speedo not working, but as for the dash backlights, it will be the fuse. you will find you don't have any tail or parking lights either. i don't know what colour wire the earlier models have, but in ours (2010) there is an orange/white wire coming out of the stereo, this is for the dimming function. when the parkers are off it is grounded, turn the parkers on and you get 12v through it.

sweet thanks for the advice ill check thius arvy after work, and tell you what the go is!

sorry bout the lateness of my reply, but im shocked to say ive co me to the discovery that my earth is fine, my acc power is fine, its infact my constant that is fucked!! its reading 0.23 volts , and i think i may know how this happened, when i was testing my starter motor, i wanted to rule out all varibles possible so i had straight leads to the starter motor without going thru the fuse box... (IDIOT!!!) anyways i hadnt connected the leads back up so they would run thru the fuses... inso facto this happened.... how do u think its possible to fix this?? any ideas im honestly stumped!!