Original Hitachi AM/FM radio speaker wiring

[J.T.L.]

So I want to keep my original Hitachi KM-1420 radio in the dash, with the output sent to speaker-level input of an amp/sound processor.

My question is which is + and which is - for the speaker wires? I've got Grey (female bullet connector) and Grey/Blue stripe (male bullet connector). Anyone know which is which?

Thanks!
J.T.

[two_68_510s]

On my old set, the Grey/blue wire is grounded on the frame of the radio:

WP_20140719_001[1].jpg (653.31 KiB) Viewed 3119 times

Whole setup:

WP_20140719_002[1].jpg (200.87 KiB) Viewed 3119 times

So, grey/blue is negative and grey is positive:

WP_20140719_003.jpg (23.19 KiB) Viewed 3118 times

[510wizard]

These old radios are before the advent of floating output (bridged ) car stereo, so the negative on the speaker is the same as the radio chassis. The next question is your amp/sound processor going to work with a non floating ground car stereo (assuming that it is the amp is a later model). In the old days we would use a Pioneer AD-304 as a booster.

[J.T.L.]

Thanks! After looking at your pic I guess I should have removed the dime-sized cover where the wires go in to take a look.

Seems to be working now, some stations are clear and sound ok (ok for running mono sound through stereo speakers), others are a bit crackly. Thanks for the advice on the non-floating ground. I was wondering about that. I think I will check with Infinity about running that on an extended basis.

Radio is build for an 8 Ohm speaker. I assume the Amp is set up to show "modern" 4 Ohm load on the speaker level inputs. So I wired it in series across the L and R speaker level inputs to show the radio the 8 Ohms it's expecting (and also to give sound out of R and L channels):
(Radio output + to amp speaker level input L+)
(amp speaker level input L- to amp speaker level input R+)
(amp speaker level input R- to radio output -)

I got a refurb JBL MS-8 that is supposed to auto-adjust the output levels based on what it "hears" through microphones during the setup. Need to get the rest of the interior put in before I run though the whole setup process. Just happy that I've got some things lighting up and some other things making noise for now.

And, of course, the pictures.

[RONSLYCHUK]

I like your lighter/headlight switch and the rear defrost/lighter.

[J.T.L.]

Thanks!
I got a JDM radio trim that has the bigger hole for the lighter on the right side and I put the lighter over there. Then I got an actual fog light switch to put in the smaller hole. I plan to use the fogs as Daytime Running Lights so now the switch I will use frequently is a whole 6 inches closer, and more importantly a conversation piece.

Post it if you have a pic of the rear defroster switch. Did I read that those were standard in Canada? I almost never see rear defrost cars, and I don't know if I've ever even seen a pic of the switch.

J.T.

[bertvorgon]

Here is a picture of my rear defroster switch, it has a blue lens in it. It all still works, which does come in handy occasionally up here in the great white north. My car is a true 1973.