Vintage Car Stereo Wiring Help

Vintage Car Stereo Wiring Help

Author
Discussion

CrutyRammers

Original Poster:

13,735 posts

199 months

Monday 2nd March 2020
quotequote all
I'm sure someone on here will have a memory for this stuff...or know how to safely work out which is which.

Background....I'm restoring an MGB. I want to keep the old radio/cassette player in place, and add a small bluetooth amp behind the dash somewhere.
The new bluetooth bit is all easy. I was planning on building a switchover box using a couple of DPDT relays in to switch the speakers from the old radio to the new amp. All good so far.

The trouble I'm having is identifying the wires on the old radio (it's a Sanyo if that helps)


Only 4. There's a socket for the ariel lead separately, and the thick earth wire is just connected to the case.
So, presumably if there's power and earth, that meant that the speakers must have been earthed to the chassis? Is that right? And does that mean that my cunning plan won't work at all?
I'm also not sure which leads were which, or how to safely test. From the tags I left on the harness when I cut it 5 years ago, I *think* that the speakers were probably the white and yellow, which would make blue the power.

Any advice gratefully received! smile

CrutyRammers

Original Poster:

13,735 posts

199 months

Monday 2nd March 2020
quotequote all
Piersman2 said:
Those just look like the power wires. A picture of the rear of the unit would help. And a model number?
I'm not sure it will smile, but here you go:


Model number is as above FT-200ME according to the label.

CrutyRammers

Original Poster:

13,735 posts

199 months

Monday 2nd March 2020
quotequote all
TonyRPH said:
I found this for a Sanyo FT200F-4 but from what I can see, yours is an FT200ME-2

Thanks. So they do earth to the chassis then. Is that likely to be a bad thing for modern speakers or don't they care?

CrutyRammers

Original Poster:

13,735 posts

199 months

Monday 2nd March 2020
quotequote all
OK this is starting to make sense.

The blue wire is slightly heavier than the black, white and yellow. I'd also taped the black, white, yellow together.
So that would suggest:
Blue: power in
White/yellow: speaker +
small black: speaker - (for both speakers)

...With the big heavy black wire from the case earthed to the chassis.

So I'll have to do some slightly different routing in my switchover box for each source but nothing difficult.
Yes it is a -ve earth BTW, I think some of the early MGBs were +ve but mine is quite a late one.

Thanks everyone for your help beer

CrutyRammers

Original Poster:

13,735 posts

199 months

Monday 2nd March 2020
quotequote all
Brilliant, thanks Tony