First Things First was the opening title for this three-part series dealing with cab upgrades and rust prevention, so it only makes sense we wrap up the last installment titled First Things Finished. For those of you that just dropped in, we started on the C10 by sealing the cab and doors with weatherstripping from Brothers. Once we knew the doors weren't going to allow water, dust, or dirt inside the next step was to insulate and soundproof the door shells and inside of the cab with Dynamat Xtreme. Next, a pair of Power Bass 6x9-inch speakers were concealed behind the crossflow ventilation louvers in the doors, and stuffed a set of 73-87.com's 6x9 speaker brackets in the cab corners. (Boom Mats and DynaXorb formed the enclosures.) Then the hand-crank window mechanisms were replaced with Brothers' easy-to-install direct-fit power windows, and the speaker and power-window wires were routed from the doors into the cab.
As soon as the new wires were pulled through we realized the stock C10 fuse block was going to be inadequate to properly handle all of the new demands placed on it. Amongst the new demands was a list full of computers. This list of computers includes the one used to control the '79's Gearstar 4L60E transmission, the Howell Developments' TBI electronic fuel injection conversion kit, and a host of smaller computers such as the one in the Dakota Digital cruise control we installed in a previous issue of CCT. All in all, the roll call of new electrical drains placed on the system includes Brothers power-windows, a Dakota Digital electronic antenna, auto-dimming rearview mirror with compass and outside thermometer, and a Dakota Digital instrument panel. The Clarion head unit relies on four 6x9-inch Power Bass speakers backed up with an ultra-thin Power Bass 12-inch sub enclosure that tucks flush against the cab wall and doesn't restrict full movement of the seat to deliver crystal clear sound. A further drain comes from a 1,600-watt Power Bass ASA6004x amplifier mounted beneath the seat.
The most recent addition is going to be a 60/40-split power bench seat snagged from a '94 Buick Roadmaster Hearse. Back in 2007 when I first bought the '79 in anticipation of increased electrical demands a Painless Performance Power Star high-output alternator engineered to deliver around 14.9-volts at low rpm was the first electrical upgrade I made to the truck. Right off the bat I noticed the Power Star was able to keep up with the truck's air conditioning even while it was idling through heavy stop-and-go traffic. Now that I've gone off the deep end and added just about every power option imaginable once again it's the folks at Painless Performance I looked to, to come up with a solution. Painless' part number 50101, 12-circuit race car fuse block utilized as an auxiliary fuse block makes for a lot better solution than overburdening the stock fuse block with numerous taps, or completely rewiring the truck with a larger-capacity fuse block. In addition to curing the too-many kittens and not enough faucets situation, the Painless Race Car fuse block is equipped with a relay that eliminates spikes in the current flow. Spikes in a vehicle's 12-volt electrical system can raise hell with computers, and make the simplest of problems almost impossible to diagnose. True to how I like to write a tech feature, I zeroed-in on the areas where I think most folks might need a little help, and left the obvious steps to the manufacturer's instruction sheet.
There's a big pile of wires...
There's a big pile of wires shown here, and not one of them is a wire that originated in the truck's factory wiring. They're all wires that need to be tied into the system.
This is the C10's stock fuse...
This is the C10's stock fuse block, and it's already been overburdened a little bit with added accessories.
The first step to mounting...
The first step to mounting the ultra-thin Power Bass 12-inch subwoofer cabinet was to find the center of the cab, and align the cabinet on center.
Next, the mounting brackets...
Next, the mounting brackets included with the sub cabinet were installed. Note how they are marked "vehicle" and "cabinet," indicating how they must be placed.
Several pilot holes were drilled...
Several pilot holes were drilled and then an equal number of the self-tapping screws included by Power Bass were tightened.
These are the type of leads...
These are the type of leads used on the Power Bass 6x9-inch speakers. The smaller lead, on the left, has a black stripe indicating that it is the negative lead.
The speaker wires to the sub...
The speaker wires to the sub cabinet were stripped as shown, and then the negative lead was pushed into the black, and the positive lead into the red to obtain correct speaker polarity.
Notice how tucking the speaker...
Notice how tucking the speaker wires behind the mounting bracket produces a clean job.
This is the computer used...
This is the computer used to manage the Gearstar 4L60E transmission. The Gearstar computer is very light and only required sharing one mounting screw with the Power Bass mounting brackets.
To ensure no exhaust fumes...
To ensure no exhaust fumes or rainwater would be able to leak into the cab, the wiring was sealed up with a silicone sealant.
Notice how the Gearstar computer...
Notice how the Gearstar computer was pinned into the corner allowing it to be affixed with only screw.
Once all of the speaker wires...
Once all of the speaker wires were connected they were grouped in a Teflon lined sheath and routed to the Power Bass amplifier.
The best electrical tape money...
The best electrical tape money can buy to produce a super clean job is professional grade 3M Super 33+. A single-edge razor blade makes a clean cut without stretching the tape.
To prevent any chance of the...
To prevent any chance of the bare positive terminal screws shorting-out on the Power Bass 1,600-watt amplifier speaker wire connections, we used 33+ to cover the leads.
The input and output RCA leads...
The input and output RCA leads to the Power Bass amplifier are easily identified with red and white markings.
With the amplifier and speakers...
With the amplifier and speakers wired, the next operation was to locate an out of the way spot to mount the Painless auxiliary fuse block. It was determined the best spot was on the passenger side adjacent the glovebox.
Here's the face of the Painless...
Here's the face of the Painless fuse block. Notice there are circuits for an electric fuel pump, electric fan, and additional accessory items that are not present on a stock C10 fuse block.
One side of the Painless fuse...
One side of the Painless fuse block provides power when the ignition switch is turned on.
And the other side provides...
And the other side provides full-time power.
Here's a view of the Painless...
Here's a view of the Painless fuse block mounted inside the dashboard along side of the glovebox. Note that we left the wires long enough that the fuse block could be withdrawn from its mounting position for servicing without disconnecting any wires.
The supply wire (Red) for...
The supply wire (Red) for the Painless fuse block was routed through the firewall on the passenger side and run to the positive post on the truck's battery.
For the Painless fuse block's...
For the Painless fuse block's 12-volt supply wire an eye terminal with a hole large enough to clear the 3/8-inch battery bolt was connected with two other leads (One provides 12-volt current to an LMC Heavy-Duty light relay kit).
To finish off installing Brothers...
To finish off installing Brothers direct-fit power-windows we needed to modify the window crank hole in the stock C10 door panel to install the power window switch.
A Sharpie was used to trace...
A Sharpie was used to trace around the profile of the window switch to indicate how big the square needed to be made for the switch.
A sharp crosscut Nicholson...
A sharp crosscut Nicholson file worked incredibly well to hog out the opening.
Special attention was paid...
Special attention was paid to filing the opening to align vertically and horizontally perfect with the lines in the door panel.
Viewing Brothers power window...
Viewing Brothers power window switch from the front proves the special attention heeded paid off with perfect installation results.
The stock '79 C10 radio antenna...
The stock '79 C10 radio antenna is a super-clean (notice the black nub) windshield contained design that worked well and meant a hole didn't have to be cut in the fender to mount a conventional antenna.
Not wanting to lose this feature...
Not wanting to lose this feature should the windshield need to be replaced, we opted for a Dakota Digital electronic antenna that amplifies the radio signal while it eliminates the need for an ugly conventional antenna.
The Dakota Digital electric...
The Dakota Digital electric antenna plugs into the radio exactly as the original antenna lead did, and then the 12-volt lead was connected to the fuse block's switched side.
Noting the front 60/40 power-seat...
Noting the front 60/40 power-seat in my '93 Buick Roadmaster wagon is way more comfortable than a stock C10 bench, I measured it for width and depth to see if I could swap one into my '79.
Although the maroon colored...
Although the maroon colored cloth on the Buick seat I found for free is quite hideous, the price was right, and now I'm going to see how much an upholstery shop wants to re-cover it.