his article shows one way to fix GM A Body blinkers for 6 dollars. You can buy a replacement blinker housing, although we don’t all have $100 to fix a simple problem, or often more than one socket needs attention. In this case, we were fixing a blinker socket on a 1972 Oldsmobile Cutlass Supreme, although most GM A-Body cars had similar or exactly the same blinker sockets.

The Symptoms of a bad blinker socket include blinkers that don’t blink, blinkers that don’t turn on at all, or blinkers that blink very slowly. On newer cars, which are NOT the scope of this article, a bad socket or burnt out bulb will usually cause the blinkers to blink rapidly. The GM A-Body platform primarily from 1968 to 1972 will most closely match this procedure, although you should apply this approach to your specific car, and find a socket that fits the bulb you are trying to use.

Isolate The Issue

First, determine what is really wrong. Turn the blink on in the direction that is not working properly, and find the bulb that is not lighting up. Check marker lights on the side, as well as tail lights in the rear, and the blinker in the front. Once you find the blinker that isn’t working, pull the bulb out and use a volt meter to measure voltage across the bulb contact(s). You should get 12 volts. If you don’t get 12 volts, you have a bad socket or socket connection. If you do get 12 volts at the socket, test the bulb by applying 12 volts to one contact (using your battery terminals is fine), and ground to the other contact or the bulb socket metal shell. The bulb should light up. If not, you have a burnt out bulb. Keep in mind that you may have enough of a connection at the socket to give you 12 volts with small load, but not a good enough connection to provide sufficient current under load. In this case, a volt meter is only partially useful.

Assuming your bulb is OK, it’s time to isolate the problem at the socket. The bulb socket grounds through the crimp joint at the socket, and then from the blinker housing through the mounting bolts into the bumper or body of the car. If you have a lot of rust at the socket crimp or on the blinker housing at the mounting bolts, this could be the cause.Note that this article also assumes your blinker switch is OK.

Parts List

Start with the easy solutions first. Remove the blinker housing and clean the rust and dirt off of the mounting bolts, housing body, and connection at the frame/body/bumper. This will ensure you have a good ground contact for your blinker. Reassemble and test. If this fixes the issue, you’re done! If not, you’ll need to repair or replace the socket.

Repairing the factory socket IS possible, although it’s not what we decided to do. Basically, you can remove the guts from your original socket through the back, and then buy a new socket with a compatible bulb type. Remove the guts from the new socket and insert them into your factory socket. Use RTV or similar to ensure no water enters and voila! you have new bulb contacts. We decided to replace the entire socket.

Start by prying open the factory crimp joint. We used 2 flathead screwdrivers. Cut the original socket wires at the socket to preserve as much factory wiring as possible. Remove the original socket through the back of the blinker housing.

Here is a parts list of what we need:

• We’re using bulb type 1157. This is the equivalent original style for a 72 Cutlass, and likely your Chevelle, Nova, Camaro, Pontiac Firebird, Etc. Same goes for the blinker sockets below, but check for your car.

  

• GM blinker socket part number is 88861018.
• After market socket part numbers include PT95 at Oreilleys, ECH LS6428 at NAPA, AC Delco LS190 or 2569F at WiringProducts.com. We bought from Wiring Products.
• For the wiring, you’ll need a soldering iron, solder, flux, heat shrink tubing, dielectric grease (optional), RTV (Optional), electrical tape, and replacement wiring harness connectors if yours are broken or missing (ours were).
• Packard 56/ Delphi 56 series connector and terminals that match your harness (1 wire, 2 wire, etc), and a proper Packard crimp tool. You can use generic flimsy terminals, however they rarely last and usually look terrible. ***New Packard Terminals or connectors are only required if your original harness is damaged, otherwise you can skip this purchase because this repair only directly requires soldering.

Repair Procedure

Strip about 1/4″ of wire on your new socket and on the end of your original wiring harness that the new socket will connect to. Slide heatshrink over each of the two wires and move out of the way. Twist your CLEAN wire ends together so that no strands are sticking out that could cause a short. Apply solder flux to the wires liberally. To solder, heat the wire on the bottom with the soldering iron, and apply the solder to the top of the wire. To solder properly, the heat from the WIRE should melt the solder, NOT the heat from the iron directly. This will prevent a cold solder. Look up proper soldering procedure if you are unsure.

Once soldered, we like to apply dielectric grease to help prevent water and direct from corroding or shorting the connection. After applying, slide the heatshrink tubing over your new joint and then wrap in electrical tape to provide additional protection. This should result in a good connection that will last for years in normal conditions.

If you need to repair the original harness, cut the old damaged harness connector off. Strip your wires and crimp on your new terminals. The new Delphi terminals then just slide into the new Delphi connector. Easy as 1-2-3.

NOTE: The bulb socket IS sensitive to direction, meaning the correct wire from the harness needs power the correct post on an 1157 bulb. If you get yours backwards the blinker won’t function properly and it will be obvious, and the bulb will likely only dimly light. To fix, remove the wires/terminals from the factor Delphi connector and the harness and reverse them. To remove the terminal, don’t just yank on it. Get a thin screwdriver or similar and slide it in from the open end of the connector to depress the catch prong that holds the terminal in. Then pull the terminal out. Look of pictures of the terminals  for more clarity if you’ve not done this before.

For the replacement sockets we recommended above, just clip them into the hole on the housing. We applied dielectric grease around the metal after clipping in the new sockets to prevent corrosion. If you’d like, prior to pressing in the new sockets, you can fill the back of the blinker socket around the wires with RTV to ensure waterproofness and prevent movement. Up to you.

Reassemble the socket and test! Done!

This process only took us about an hour start to finish, and cost a total of $6 and a little solder and tape. We repeated this process for the other 3 bad sockets on the car. Thanks for reading!

LEFTLANEBRAIN