Lost key for 1971 GMC half-ton truck

On my late grandma’s farm there is a 1971 GMC half-ton pick up truck that my dad wants to be able to use for firewood, and other things. The problem is he has recently lost the key, hours of searching come to no avail.

I have been trying to find information for him on bypassing the key. The cab is not locked, he just needs to start it, even if only to make sure a new carburetor works. A couple people have suggested that hot wiring it involves finding the ignition wires, and tapping them for a spark. They also say turning it off would involve choking it til it dies, or disconnecting the battery.

What I want to know is, if dad doesn’t feel like getting key stuff changed in it, which is entirely likely given his and my financial situations, is it possible to connect a button for turning it over, and one for using the ignition wiring to turn it off? I’m not sure whether it has a manual choke in the cabin, and disconnecting the battery seems like a hassle for something he may be driving with any frequency

I wuuld suggest consulting a locksmith before you mess with the wiring. Back in 1971, I purchased a used 1968 AMC Javelin. I promptly lost the trunk key and had a cabbage in the trunk. Although I bought the car at a used car lot, I called the dealer who initally sold the car and explained the situation. The dealer was able to furnish the key number and I went to a locksmith. I didn’t need the key number. The locksmith picked the lock and had the trunk open in seconds. He then removed the lock cyliner and made a key to fit the cylinder. The cost, at that time, was under $10. Of course, two days after I had a new key made, I found the lost key.

Is the key in the dash or in the side of the steering column??

if it’s in the dash, it can be easily removed and a new switch with a new set of keys installed. About $30. If it’s in the column, Drive a square shanked screw driver of the appropriate size into the lock with a hammer. Use a Cresant wrench to turn the screw driver. Work it back and forth until it turns freely without needing a key…

I lost the key for my '65 GMC and 60.00 paid toward a locksmith got me two keys in about 20 min.

You certainly could install a push button and an “on/off” switch.


New lock cylinder with keys is $8. It may not hurt to also get a new ignition switch for $20, just in case something happens to the other one replacing it.

If you have a locking glove box the code may be stamped on that lock. You can take that code to a locksmith and they can cut a new key for a couple of bucks. The only problem might be if it was one of those models that had 2 keys, one for the doors and one for the ignition. Did the same key work the doors and ignition? If so you may be in luck.

Take the VIN to a GM dealer,they should be able to cut you a new key.