cruiser
Well-Known Member
Good evening fellow Moparites! Welcome back to another sleep inducing bedtime story from the A body world. Tonight's episode is a bit different and likely something that you've never come across at a car show - a 1974 A body with factory cruise control. So we'll begin with a disclaimer: Chrysler didn't offer cruise control as an option on A bodies until 1975. But with my cross country road trip coming up next year, I decided to add cruise control to my 1974 Duster to make the trip more tolerable. There are a number of aftermarket cruise setups available, all of which I rejected as they didn't have the factory look that I like. So this left me with retrofitting a factory setup into my Duster which wasn't available when the car was built in late 1973. Step one was to research what would work, and I learned that the 1975 system would work just fine in my car. Many of the components of the Chrysler cruise control systems were common to all cars in the A, B, C and E body fleets back then. Basically, it was a modular system that could be easily plugged into a vehicle as an option when the car travelled down the assembly line. The system was composed of a vacuum operated throttle servo and its carb linkage, a controller on the turn signal stalk, a wiring harness with a brake cutout switch, and two speedometer cables (one from the trans to the servo, the other from the servo to the speedometer). Yep, finding all this stuff was quite a challenge. Since my car has the 225 slant six motor, finding the throttle linkage was tough. Very few slant six powered vehicles came with cruise control, but I found a slant six powered 1979 Volare in a salvage yard that provided the very rare Holley 1945 one barrel carb linkage (also described in the shop manual as the "lost motion link"), the correct length servo-to-carb cable and its unique dual attachment bracket, the servo mounting bracket, and the speedometer cables. A 1971 Chrysler sedan supplied the wiring harness. I bought the servo, control stalk and brake switch NOS on e-Bay. And yeah, it was expensive but I didn't want to gamble on the unreliability of used parts since I'll be keeping the car for a long time. Step one was to spread it all out on my basement floor and figure out how it went together. My factory 1974 shop manual was helpful in describing the system layout for B and E body cars. I bead blasted the rusty servo bracket, then finished it in three coats of self etching primer follower by three finish coats of Krylon Satin Black spray paint (see before and after photos below). Once dry, I mounted the NOS vacuum servo to the bracket using the original nuts which I de-rusted with Evapo-Rust. I had to replace the crumbling original foam air filter that came with the NOS servo with new foam before I installed the servo. The final photo below shows the new foam air filter underneath its aluminum cover on the side of the servo. The throttle cable was pretty bad. These things are nearly impossible to find for the A body, and the one off the Volare was the correct length but was shedding its plastic cable covering, revealing the steel cable housing underneath (see photos). The cable itself was sound, so I removed the remainder of the damaged plastic cover then cleaned up the bare steel cable cover. I had to replace the missing covering, so I carefully masked it off then hit it with eight coats of Plasti Dip aerosol black rubber coating. I was very happy with the resulting finish, which is extremely durable. I attached the cable to the servo, then mounted the servo to the inner fender using online photos of a 1975 Duster cruise installation as a guide. The inner fender was not dimpled for these holes, so the aforementioned photos helped a lot. Next, I installed the dual throttle cable bracket and the lost motion link, then attached the cable to the carb linkage and installed a new vacuum supply hose from the brake booster to the servo using the correct red steel spring clamps. I then removed and discarded the speedometer cable and installed the replacement dual speedometer cables from the trans to the servo, and from the servo to the speedometer. Next came the wiring harness installation, which provided its own unique challenge. Since there was no factory opening in the firewall for the harness to pass through, I looked under the dash and found an oval plastic plug that covered the unused clutch linkage hole. The wiring harness came with a rubber grommet with the wires passing through its center. I cut a hole in the plastic plug the diameter of the rubber grommet, then mounted the grommet into the plug and installed it all into the firewall creating a very factory looking fit. I then replaced the original brake light switch with the NOS dual brake/cruise control disconnect switch. The new switch fit perfectly into the original bracket under the dash and didn't even need any adjusting - I merely used the original factory position of the switch. Next, I disassembled the top end of the steering column and removed the stock turn signal lever. I then removed the male connector at the end of the cruise controller and fished the wires through the column, then reinstalled the connector and hooked it into the wiring harness. Consulting the electrical section of my shop manual, I found an unused switched power supply under the driver's side cowl that supplied an ignition feed for a rear defroster. I connected the cruise control wiring harness to this power supply and now I had 12 volt power to the system. With everything installed it was now time to road test it, and it took a lot of tinkering to get it working right. But now that it does I love the way it works and looks in my car. The photo of the stalk shows exactly what a 1974 A body would look like had cruise control been available that year. The system holds the car's speed within plus or minus one mph on the highway. I'm really happy that I decided to go with the factory setup, even though it probably cost me over twice as much as an aftermarket system. Since I have to look at it for the rest of my life, I think it was worth it. That's all for now, kids. I hope that you're ready to fall asleep after reading this, so go get into your jammies and enjoy a nice long nap. Night night!
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