by John Pfanstiehl
Sometimes the little things have to be taken care of. And the courtesy light switches and door ajar switches are little things, both figuratively and literally. They are not essential in the sense that if they fail, they won’t strand a Corvette. However, both drivers and passengers can appreciate having courtesy lights illuminate the interior at night when either door is opened. The door ajar switch is particularly valuable. Alerting a driver to an unlatched door before moving the car can avert costly damage. Plus either switch can look shabby with corrosion, bent shafts or over spray after decades of use.
Replacement of these switches is easy. Replacing these parts can be done while sitting down and while wearing clean clothes. If everything goes right, replacement can take just several minutes per switch. The battery does not have to be disconnected and no fuses have to be pulled. These are grounding switches, so the most that can happen is a little spark or the courtesy lights illuminating. Working on 50-year-old cars can present challenges though, so Zip Corvette will show you how to handle those.
01: Unscrew the courtesy light switches with a 7/16-inch deep socket. If the threads are seized, spray them with a penetrant and come back later. After unscrewing the switch, gently pull and wiggle it out. The back end of the switch can be a snug fit when going through the threaded hole.
02: Zip Corvette’s reproduction 1968-1974 Courtesy Light Switches for the door jamb are quite an improvement over the corroded switches they’ll replace. Note that the 1975-1982 Courtesy Light Switch changed to use spade terminals.
03: Tip: consider breaking the plastic portion of the old switch if the wire terminals are in good shape. The tips of these wire ends are very fragile where they are bent back on themselves. Compressing the tip inward to remove it and then later prying it open for reinsertion is often enough to break an old terminal.
04: Fortunately, Zip Corvette offers new 1969-1974 Door & Hood Switch Wire Terminals for Corvettes. Ordering these is strongly recommended so they’ll be on hand when replacing Door Ajar and Courtesy Switches.
05: If the original terminals are reused, bend the tang out before reinsertion. If the tang of the new or old terminal doesn’t engage with the plastic sufficiently to hold the terminal end out in position above the plastic when pressed through, apply a little super glue or a fast drying cement.
06: The replacement wire terminals were needed on this car. Soldering the terminals to the wires is not essential but it does ensure a good electrical and mechanical connection. Insert the terminals tang side out into the new switch. The white wire is for the courtesy lights.
07: The switch spring is strong. Tip: compress the spring and temporarily hold it open with a shim such as a small nut. That makes it easier to fully insert the wire terminal so that its end protrudes through the plastic as shown.
08: Reinstall the switch being careful not to cross thread it. Check to make sure the switch has a good electrical connection when the door is open so that the courtesy lights always illuminate. The new switch ensures that the courtesy lights illuminate when this door is opened, and it looks a lot better.
09: There was a surprise on the passenger side courtesy light switch: a spade terminal which was used in later years. It’s likely that a previous repairer installed a spade terminal and the later model switch years ago when the other terminals were not available. Zip Corvette’s replacement terminals enabled the original style switch to be installed.
10: If the wire retreats into the switch hole, remove the sill plate and kick panel to access it. For step by step instructions on how to remove a sill plate, see Zip’s technical article “1968-1977 Corvette Sill Plate Replacement“. Tip: to avoid this extra work, attach an alligator clip or other clip on the wire to hold it out after removing the switch. Note: only one wire (for the courtesy lights) connects to the passenger side switch on this 1973 Corvette.
11: The old door ajar switch is painted, bent and corroded. If the switch requires a lot of force to break loose, apply penetrant and wait. It’s best to avoid breaking loose the plate that’s riveted to the fiberglass.
12: Zip Corvette’s reproduction 1968-1973 Door Ajar & 1968-1974 Hood Alarm Switches are also quite an improvement over the corroded and damaged switches they’ll replace. Note: the door ajar switches are shorter than the courtesy light switches.
13: Tip: if the wires are creating resistance though being wound up as the switch is unscrewed (or when being reinstalled), push in on the post so that the wires won’t be twisted.
14: Another surprise: the door ajar wire terminals here are also spades. In 1974, the Door Ajar Switches changed to use these spade terminals. It looks like some late production 1973 Corvettes changed to the 1974 door ajar switches.
15: The spade type switches are easier to replace because their wire terminals simply slide on and off; they don’t have the breakage problem common to the earlier style. Tip: remove and reinstall one wire at a time so it doesn’t retract into the hole. Use needle nose pliers both to grasp the terminal and to crimp its end if needed to make a tight fit on the switch.
16: If the wires slip inside, remove the plate in front of the rear tire. If the threads on the switch hole are corroded, use a 3/8-24 rethreader tap to cut just a couple threads.
17: Zip Corvette also offers the 1968-1976 Door Ajar Warning Switch Grommets. These rubber grommets are located interior of the switch. They are sold in pairs and are made in the USA.
18: The replacement switch is in place and the warning light works again. As an added bonus, the replacement switch does dress up the door jam. The Door Ajar light should illuminate when either door is not fully latched closed when the ignition is on.
19: Zip Corvette offers the 1970-1972 Door Ajar Switch Bumpers. These affix to the door after removing the tear-off strip from the adhesive on their back side. If the door ajar light is still illuminated when the door is fully closed, these may be a solution. They are made in the USA.
20: The alarm switch that is located under the hood is even easier to access and replace. This switch suffers the elements in the engine compartment making its life harder than the door ajar switches.
1968-1982 Door Ajar and Courtesy Light Switch Replacement
Source: Zip Corvette Parts
8067 Fast Lane | Mechanicsville, VA 23111 | (800) 962-9632
Corvette Parts List Related to Article:
- 1968-1973 Door Ajar & 1968-1974 Hood Alarm Switch
- 1974-1976 Door Ajar & 1975-1982 Hood Alarm Switch
- 1968-1974 Courtesy Light Switch – Door Jamb
- 1975-1977 LH & 1978-1982 RH Courtesy Light Door Jamb Switch
- 1969-1974 Door & Hood Switch Wire Terminals
- 1970-1972 Door Ajar Switch Bumper
- 1968-1976 Door Ajar Warning Switch Grommet