All,

I had a different long-winded, overly detailed explanation of installing a RetroManufacturing [RM] head unit into Dad’s ‘69, but I reduced it to this posting* because I gave myself a headache proofreading the first draft.

*This one’s lengthy, but “condensed,” with pics!


Here we go!

These are the modifications I made to their instructions / installation:

1) A set of reproduction OE *****, STEREO (not mono), with the secondary *****: the balance & fader ***** are required for the way the RM head unit functions. I sourced mine from Keen Corvette, part number 330113, $32 as of writing this.

Why? OE repro **** vs RM metal ****:

OE (left) ; RM, Metal (right)

OE (left) ; RM, Metal (right)


2) 3/8”-24 nuts, 2 of ‘em to use to set depth on the shafts.

3) Wiring & fuses because of the way I designed an amp into the system. And the strange RM harness that comes with their head units. [This is covered in the next post in the thread.]


MECHANICAL aka Install:

[This assumes the gauge console is out of the car, and the OE radio has been removed]


First things first, take the RM ‘Control Shafts’ and give ‘em a lil bit of a pinch with pliers, and test the fit the OE ***** [here, left, the silver side is pinched, an OE **** fits nicely, the brass/gold is where the secondary ***** fit (balance & fader *****), and the threaded section will be used to set **** depth]:




Follow RM instructions for installing the head unit in the console, like so:


Lightly install the ‘InfiniMount’ brackets to the head unit - 4 screws per side (you will have to slide ‘em back-n-forth during install):


Install the ‘Control Shafts’ per RM instructions, BUT!!! add in the 3/8”-24 nuts [2, mentioned above] with RM shaft washers on both sides, like so:


[Using a typical ol’ hex nut makes the ‘Control Shafts’ adjustment easier, and adds some rigidity to the install.]

Install the plastic spacer to the ‘Control Shaft’ against the washer & hex nut:



This last pic shows the shaft washer up against the plastic spacer; above it, you can see the washer on the opposite side of the hex nut -> shaft washer on both sides of the hex nut.

Move that ‘InfiniMount’ bracket [back-n-forth] as you need to, and slip the pinched end of the ‘Control Shaft’ through the console:

Note the hardware is loose at this point


From the front (gauge face side), install the cupped plastic washer, then a shaft washer & RM shaft nut:





Set depth:

You’ll have to move the hex & shaft nuts a lil bit to get the depth set so those secondary ***** sit nicely, and the outer ***** can turn AND momentary push in / pop out - forgot that earlier.

It helps if you move the rear nut out of the way, and set it last, this will also help align the ‘InfiniMount’ brackets to the hex nut & head unit:



Once the depth is set for the *****, snug the front (outward facing) RM shaft nut while counter-holding the hex nut [see, there’s a reason for this mod … you can get a wrench in there!!!]:

Wrench on hex nut

Better view (?)


Now, semi-snug up that “last nut,” and semi-snug the ‘InfiniMount’ bracket screws. And if you’re detail oriented, you’ll see the ‘Control Shaft’ may rotate, just get it where ya want it based on secondary **** clocking:

Secondary **** a lil past 9:00

Closer to better

Final snug down of “last nut”

When you’re satisfied, snug down the “last nut” while indexing the ‘Control Shaft’ and secondary ****. [Took me a few tries.]

Voila!
Installed !!! ???

Almost…

Don’t forget the back-strap - RM supplies one.

I’m 90% sure this right-angle-bracket I used was from the mono multiplexer (?) I removed:

Multiplexer right-angle bracket on clock housing lower screw

Came in handy for this portion.

Back-strap installed to lower Clock Housing screw.

Wrapped down to RM mounting position:


Then…
Removed back-strap, slid heat shrink over it [3/4” or 1” - can’t remember], just to prevent wire rubbing / chafing on the back-strap edges:


Because I was doing an oil pressure gauge line upgrade at the same time [posted here: https://www.corvetteforum.com/forums/c3-tech-performance/4930269-oil-system-ewoesi-itis-not-that-bado.html], I added a plastic shield to the build:




1/8” clear plastic, cut in a trapezoid, enough to bow it when installed, and overlap edges.

Then I made sure the RM Control Shafts got their wiring tightened up - loops with cable ties. It’s in the pics above.

If the oil line leaks, maybe that plastic will save the radio.

Original vs RetroManufacturing:

Original radio (in the Vette)

RetroManufacturing (on the bench, OE ***** look pretty good on the RM head unit)

NOTEWORTHY: The pinch on the shafts lends itself to the ***** running in an out-of-round fashion: wobbly, if you will.
ADJUSTMENT: note high side, remove ****, rotate 180° and reinstall - I think I marked mine with a sharpie dot, pulled it off and reset it. Minimal ‘wobble’ to the ***** at this point.


NEXT POST, WIRING!

 

All,

To continue…

WIRING:

RM has a good (it’s ok…) diagram in their instructions. But I cannot for the life of me figure out why:

A) The memory wire is fused at 15A (it CANT be that high, memory wires are 1-2A max, typically)

B) There’s no fuse for the battery power wire [B+]


My work-around:

1) Packard 56 connectors & terminals [sourced from CustomConnectorKits dot com]

2) A separate glass in-line fuse holder [Amazon, 12AWG, “Crimp Supply”, orange wire in pic, mine showed up yellow - like I wanted]

3) 15A glass fuse [but for my set-up of: radio, amplifier, and dash/rear cameras, I used a 30A]


Because there’s no fuse on the RM B+ wire, I opted to use the factory fuse box 10A Radio fuse & lead. Then install an in-line fuse holder [2 above, work-around] at the fuse box Battery Constant terminal in the fuse box.


The alternator has been upgraded to a PowerMaster and Ed Law [“in returns” at PowerMaster was kind enough to walk me through the changes in how their alternator isn’t quite a 10- or 12- SI].


The OE radio lead [wires] are:

Gray: illumination -> not needed
Black: ground
Yellow: power -> B+ key on, fused
…for a ‘69, check your wiring manual for correct wire assignments.


The RM radio harness wires are:

Yellow: memory -> Battery Constant
Red: power -> B+ key on
Black: ground
Blue / White: amp remote turn-on

Other wires: depends on your application, consult RM install instructions [speakers, subwoofer RCA, power antenna, etc…]


If you follow both wiring diagrams:

OE … Connects to … RM
Yellow ……………….. Red
Gray …………………. Nothing*
Black ………………… Black


[*RM unit does not require illumination wire, see Operating Manual.]


CustomConnectorKits:

Packard 3-pin:
Male: 02973172
Female: 02962510

12AWG** terminals:
Male: 02971859-L
Female: 12124518-L

[**based on quality of crimping and M-to-F terminal fit, I do not recommend the 14-16AWG Packard terminals]

So a 3-pin Packard connector replaces the OE 3-pin (flat, OE) connector:

The white connector goes in the back of the head unit. I removed all the wires except: power (B+, key on), ground, memory, and amp remote-on


RM side, red and black (B+, key on; ground) in 3-pin connector


Using Packard male terminals will allow you to plug a modified RM harness into the OE (female) terminals:

Plugged in -> red (RM) to yellow (OE car-side)

Another view of wire assignment on car-side. NOTE: gray (illumination) is not used, but is assigned (no wire on the RM harness side)

[Sorry, bad lighting and the ground wire is a lil hard to see.]

Changing the connectors means no new terminals to crimp on the car-side.

 

I have also run several redundant grounds for the cabin electrical.
The amp is grounded to the dash frame, and runs over to the (redundant) wiper ground I installed … to the left-side of the cluster:





With the amp installed where the mono multiplexer used to be*, I have some more wiring to finish up.



*it's on a custom-made ABS plastic sheet; had to contort it to fit. The extra fuse (distribution) block is for the radio 15A memory [see previous], the amp 15A power, and 2x 2A fuses for the dash/rear cams.

Another view of it before install:

Amp on ABS plate, fuse (distribution) block at top

And for a size reference of the amp:

It’s the size of a pound of butter.

Height profile