1986 740 GLE Cruise Control

[Kmaniac in California USA]

The more I learn about my Volvo, the more I LOVE IT!!!

A few days ago, I took a walk through a local junkyard and discovered another 1986 740 GLE. The only difference between this one and mine was exterior color (medium blue) and it had factory cruise control. I took some other odds & ends off, but kept thinking that is would be nice if I could add the cruise control to my car.

My Haynes manual (yep, that's Haynes) showed a nice blow up of all the components for the cruise control system, including a description of each component and a wiring diagram. I looked as though all I needed to do was pull all the components, the vacuum tubes and the wiring harness. A very simple job.

Yesterday afternoon, I went back to the junkyard. Within less than one hour, I had located and pulled all the components, including the vacuum tubes. The only problem was the wiring harness. It seems that the wiring for the cruise control was woven into the main wiring harnesses, it was not a separate harness laid in special for this option. After looking at this and thinking about it, I began to speculate that maybe all the cars manufactured were wired for all the accessories at the factory. That would sure make it easier for a Dealer to add a missing accessory if a Customer requested it. I hedged my bets and left the wiring in the junkyard.

When I got home, I opened the hood of my Volvo and attempted to locate the wiring connection for the underhood vacuum pump. I found it tied up behind the left headlight. Under the dashboard I found the connectors for the control unit and the brake switch hanging where they were suppose to be. When I disassembled the steering wheel and removed the old turnsignal switch, I found the connector for the cruise control switch hanging unused, right there. The electrical lead to the speedometer was already in place. There was even an unused mounting bracket in place for the brake switch. I installed all the cruise related components in their respective places, connecting them with the existing connectors in the harness. The full installation took me about one hour.

Once the installation was complete, I took the car for a drive. Out on an open road, I brought the car up to 50 mph on a downhill grade. I turned the cruise switch on, pressed the set switch and took my foot off the throttle. As I began to climb a slight grade, the car accelerated and maintained the speed all by itself. SUCCESS!

The lesson I learned here is that these cars are all prewired for every accessory available. If you want to add one, find it, install it and plug it into the empty connectors in your wiring harness. This is very simple and very easy.