Eunos Radio Wiring

[Gad-Westy]

Need to fit a new stereo and it appears the previous owner of our car has completely butchered the wiring. Can anybody tell me which wires are which, particularly which the ground/earth is? Unfortunately the original Mazda connector has been removed otherwise I'd just buy an adaptor.

[MrV]

Stolen from here so don't blame me if its wrong

1990 Mazda Miata MX5 Car Radio Stereo Wiring Diagram

Car Radio Battery Constant 12v+ Wire: Blue/Red
Car Radio Accessory Switched 12v+ Wire: Blue/White
Car Radio Ground Wire: Chassis
Car Radio Illumination Wire: Red/Black
Car Stereo Dimmer Wire: N/A
Car Stereo Antenna Trigger: N/A
Car Stereo Amp Trigger Wire: N/A
Car Stereo Amplifier Location: N/A
Car Audio Front Speakers Size: 6 1/2″
Car Audio Front Speakers Location: Doors
Left Front Speaker Positive Wire (+): Blue
Left Front Speaker Negative Wire (-): Blue/White
Right Front Speaker Positive Wire (+): Blue/Red
Right Front Speaker Negative Wire (-): Blue/Yellow
Car Audio Rear Speakers Size: 3 1/2″
Car Audio Rear Speakers Location: Head Rest
Left Rear Speaker Positive Wire (+): Blue/White
Left Rear Speaker Negative Wire (-): Blue/Green
Right Rear Speaker Positive Wire (+): Blue/Red
Right Rear Speaker Negative Wire (-): Blue/Green

[Gad-Westy]

MrV said:

Stolen from here so don't blame me if its wrong

1990 Mazda Miata MX5 Car Radio Stereo Wiring Diagram

Car Radio Battery Constant 12v+ Wire: Blue/Red
Car Radio Accessory Switched 12v+ Wire: Blue/White
Car Radio Ground Wire: Chassis
Car Radio Illumination Wire: Red/Black
Car Stereo Dimmer Wire: N/A
Car Stereo Antenna Trigger: N/A
Car Stereo Amp Trigger Wire: N/A
Car Stereo Amplifier Location: N/A
Car Audio Front Speakers Size: 6 1/2″
Car Audio Front Speakers Location: Doors
Left Front Speaker Positive Wire (+): Blue
Left Front Speaker Negative Wire (-): Blue/White
Right Front Speaker Positive Wire (+): Blue/Red
Right Front Speaker Negative Wire (-): Blue/Yellow
Car Audio Rear Speakers Size: 3 1/2″
Car Audio Rear Speakers Location: Head Rest
Left Rear Speaker Positive Wire (+): Blue/White
Left Rear Speaker Negative Wire (-): Blue/Green
Right Rear Speaker Positive Wire (+): Blue/Red
Right Rear Speaker Negative Wire (-): Blue/Green

Cheers Mr V. I think I found that list myself earlier but for earth/ground, it just states 'chassis'. Just wonderring whether there is a wire in place already for this and what colour its likely to be.

[MrV]

I am sure mine is black

Its pretty easy to pull an earth off the chassis if thats not the case.

[Gad-Westy]

MrV said:

I am sure mine is black

Its pretty easy to pull an earth off the chassis if thats not the case.

Cheers, many thanks.

[Gad-Westy]

Ok, halfway there, got the power side sorted but the speaker wires on my car bear no resemblance to the colours listed above. Any wiring diagrams available? Its a 1990 Eunos if it matters.

[MX-5 Lazza]

I thought it was:
Red - 12v permanent live
Blue - 12v switched live
Orange - Illumination
Black - Earth

I think if I was you I'd get a harness adapter, cut the harness end off and hard-wire it into the harness wires. At least that way you'd have a wired ISO connector so it will be easy to plug a stereo in.

[Gad-Westy]

MX-5 Lazza said:

I thought it was:
Red - 12v permanent live
Blue - 12v switched live
Orange - Illumination
Black - Earth

I think if I was you I'd get a harness adapter, cut the harness end off and hard-wire it into the harness wires. At least that way you'd have a wired ISO connector so it will be easy to plug a stereo in.

The wiring in our Eunos certainly doesn't follow that convention, if only it did! I have now wired on an ISO connector, just not sure I've got the correct polarities on the speakers.

[MX-5 Lazza]

I've only fitted stereos in a 98 and an 01, both of which conformed to ISO standards (though the stereo block wasn't ISO). I guess earlier cars conformed to older standards...

[MrV]

Gad-Westy said:

MX-5 Lazza said:

I thought it was:
Red - 12v permanent live
Blue - 12v switched live
Orange - Illumination
Black - Earth

I think if I was you I'd get a harness adapter, cut the harness end off and hard-wire it into the harness wires. At least that way you'd have a wired ISO connector so it will be easy to plug a stereo in.

The wiring in our Eunos certainly doesn't follow that convention, if only it did! I have now wired on an ISO connector, just not sure I've got the correct polarities on the speakers.

Will pull mine out later and have a look for you as by some strange reason both my front speakers have died over night

[Gad-Westy]

MrV, hope you get them sorted. Will check back to see if you found anything. Just which colour speaker iso wires go to which speaker wires would be great.