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I am wondering how to test lock solenoids that I have from a 71/72 Cutlass so that I can place them up in a For Sale thread. I tried looking through the service manual for a way to test them and found nothing. I did a search on the site here and came up with zilch. I would like to sell them but I don't want to place an ad unless I know whether they work or not. Here is a pic of one which shows there are two tabs. Do I connect a ground lead to one and if so which one? Then do I just touch the power lead to the remaining tab to activate the mechanism? Any help is appreciated.
Ground the case and then touch the power lead to one terminal at a time. One terminal will cause the rod to extend, and the other terminal will cause the rod to retract.
I don't know the first thing about those particular solenoids, but I would use a multimeter to measure the resistance between each of the terminals and the casing to determine for certain that the solenoid grounds through the casing. The solenoids on my "other" vehicle have only the two electrical terminals. A basic solenoid generates a magnetic field based on direction the current flows through the coils, so simply reversing polarity causes the magnetic field to reverse.
I don't know the first thing about those particular solenoids, but I would use a multimeter to measure the resistance ….
Good idea, I’m figuring it’s worth my time to see if I can get the other to work. Hopefully cleaning up the outer casings and cleaning up the lock switches I’ll get a few more bucks for the set.
Unlike the newer plastic lock solenoids which use a reversing polarity across 2 terminals, these do not. They work like the early power window motors, case ground and each terminal controls one direction. I do know something about them as I have installed multiple sets in my cars. In fact, I just finished installing a set in my 71 holiday coupe last week.
Last edited by Loaded68W34; January 4th, 2022 at 04:08 PM.
Thanks for the info. You are correct, the ones I'm familiar with are the newer type. So these old ones have two separate coils in them, wound in reverse of each other?
Quote:
Originally Posted by tdhill01View Post
Okay, I tried it and the left side worked but the right side I was just getting a spark from it. Is there a way to to repair these easily?
okay, I just came across an old thread Rob wrote about taking them apart. I’ll give it a try and hope for the best.
If the right side sparks, that means you have continuity. Can you move the plunger in and out? If not its probably rusted/corroded internally.
Could you post the link to that repair thread? Thanks!
Quote:
Originally Posted by tdhill01View Post
...okay, I just came across an old thread Rob wrote about taking them apart...
Hi, here is the thread I was referring to. Take a look at post number 6 that Rob (Lady72nRob71) has posted. https://classicoldsmobile.com/forums...ctuator-12614/ . He only wrote about how to take them apart but nothing on how to repair them. I hope this helps you.
Thanks for the info. You are correct, the ones I'm familiar with are the newer type. So these old ones have two separate coils in them, wound in reverse of each other?
These older lock solenoids have two coils, but I believe they are mounted above and below the center line of the plunger. The only way for an electromagnet to change linear direction with a change in polarity is if it is adjacent to a permanent magnet (or another electromagnet that is given a specific polarity to oppose/ attract the first electromagnet). If you think about most of the basic solenoids in our old cars (starter {solenoid not motor}, th400 kick down, A/C idle, electric trunk release, etc.) they simply contain a coil of wire around a movable plunger made of ferrous material. Energize the coil, and the plunger is pulled into the magnetic field. Applying a reverse polarity to a simple solenoid like this will still cause the plunger to be pulled into the magnetic field the same direction as before. If you think about a speaker on the other hand where the electromagnetic coil is housed within a permanent magnet, now movement can occur in both directions based on polarity. Power window and seat motors operate the same way where the stator and rotor each have electromagnets that can attract or repel each other based on the polarity of the electricity supplied. Most newer lock "solenoids" are not actually solenoids at all, but rather actuators. They contain small permanent magnet DC motors that move the plunger up and down.
Agree with 4R5. The side that is giving a spark will likely need to be re-wound as it is likely shorted out. As asked, does the rod move on this one? Also, with the case grounded, when you touch each terminal to power separately does each one spark, or just one of them? The coil will be made of magnet wire. It may look like bare copper but it is actually copper wire with a very thin coating of plastic or resin on it. The plastic is necessary to make the current flow through the entire length of the coil. If the plastic is compromised, the current is able to bypass the full length of wire in the coil and short circuit. It may be possible to re-wind the coil, but you would need to find the correct gauge magnet wire to handle the current. (probably a job for the next guy if your looking to sell them anyway) A shop that specializes in small DC motor rebuilds (alternator/ starter) may be able to help.
Last edited by Loaded68W34; January 5th, 2022 at 11:55 AM.
January 4th, 2022, 01:01 PM
