Radio connection

[rjt1951]

I have purchased a radio for my 1970 Minor. It is switched to posative earth as is the car. From the back come 3 wires, One thicker in blue and 2 thin wires a red and a black. I think they must be for the speaker and I assume that thethicker blue will go to the fuse box. I will fit an in-line fuse. The radio is a sonix, made in japan around 1970. Just don't want the whole thing to go bang, any ideas?
Many thanks
Richard

[Jefftav]

Post up a photo of the wires and radio as I think the speakers are usually fed with two wires and the supply is usually red & black?

[rjt1951]

Thanks will do when I can find the camera. There are only 3 wires comming from the back. athin red a thin black and aa thicker blue.

[bmcecosse]

Speakers are usually black and black/white stripe. I would imagine red to be +ve (earth in your case) and black to be -ve. Is it a mono wireless?

[rjt1951]

Hi,
It is a mono system as far as I can tell

[bmcecosse]

I think you need to open it up and see where that blue wire goes...... If it's a power feed - that will be obvious.

[rjt1951]

Thanks for advice. Blue inside goes to the back of the on/off switch so guess that means it is the power feed.

[PSL184]

Thick blue is the live feed so in line fuse and power it from the fuse box. The case of the radio will need to be earthed either through the fixing bracket or via a separate lead. (note correct polarity). The 2 thin wires are the speaker, red to the positive side of the speaker and black to the negative (although I wouldn't worry too much about speaker polarity in this application).

[bmcecosse]

Are you sure PSL? Will one side of the speaker feed not be earthed to the +ve earth chassis?

[rjt1951]

Thank you all for your help. I have now installed radio under dash below glove box. Have also installed aerial . Have purchased an old goodmans speaker from e-bay and about to make a small housing for it to sit on parcel shelf out of the way. Will then connect as you suggest, there is a dot of red paint on one speaker terminal which I will attach the red wire to and the black to the other. Just one question, what fuse rating should I use in the in-line fuse housing? I will fit it close to the fuse box end and then it's fingers crossed. If there is a big bang or a fry-up I will let you all know.

[bmcecosse]

1 amp should be plenty - but 5 will still provide protection.

[rjt1951]

Many thanks

[rjt1951]

All done and it works!!!!
Thanks for all who supplied advise.