Swap AM Delco to AM/FM Delco Question

[murguia]

I just picked up a really nice AM/FM Delco radio and I want to swap my original AM one out. I was going to remove it but I noticed the rear plugs are different. Is that the case with all AM/FM

If so does anyone have the AM/FM plugs in good shape they'd part with?

Thanks in advance

[Ironhorse]

Can you post up some pics of the am/fm you bought? Are you sure it is a GM Delco 67-72 original? The newer square body trucks may use a differant rear plug. When I installed my fatory original truck am/fm the rear plug hookup used only a three wire setup. Wish I could be more help.

[murguia]

Sorry, I should've been more specific. The new radio is for my 77. It's correct for the 77 and squarbodies. It has the vertical 3 plug outlet but the AM factory in my truck doesn't have that setup

[murguia]

I just bought the correct plugs off of ebay, so I just need to splice into the old wires and plug them in now?

[murguia]

I'll figure it out

Thanks for the response IronHorse, I appreciate the response

Nick

[Ironhorse]

Sorry did not get back to you quicker. Have very little radio experience with the square bodied trucks. Do you know what year of mfg. the radio is? Should be a paper number / code sticker on the radio. Maybe take it to a radio shop and see if they can track it down. If the radio is for perhaps a Suburban with a 4 speaker set up it may use a differant plug than from a single seat pickup ? Just a thought, good luck with getting some tunes going.

[murguia]

Thanks a lot brotha!

[ray_mcavoy]

The reason the connectors are different is because GM changed to a different style of radio connector in most of their vehicles (including these trucks) in 1978.

As you've already figured out, you can splice in the matching connectors that will allow you to use that 78+ radio in your 77 truck.

If the new connectors you bought have OE wire colors you can match them up to the existing wires (yellow is switched +12V, gray is the dial light, black is ground, and the others are speaker wires). Most 78+ radios have provisions for 4 speakers but you don't need to use all of them. Just make sure any unused speaker wires coming out of the radio connectors are well insulated so they don't short to ground or anything.

[motornut]

your newer radio wires up like this
the old one may ran a chassis ground to the speaker.(don't do this with the newer one)