The starter on my 41 Oldsmobile is suddenly dead. 6 volt original. It was working perfectly until about a month ago. Since then I have not attempted to start the engine as I was concentrated on installing the restored radio and the glovebox with a clock and all its wiring for lights as well. The radio requires a power wire to the ignition switch. Yesterday I finally finished the job and today wanted to go out for a ride and test how radio and instrument lights work. When I turned the ignition key and pressed the starter pedal there was absolutely nothing, not a click, not a hum, nothing at all. Many attempts and no signs of power to the starter.


I am very suspicious that I placed the wires of the ignition in the wrong connectors when adding the radio wire and need help to sort it out.

The switch has 3 connectors shown on this photo from today, labeled 1-3, taking from above and behind the dashboard (I can not see what is in the photo, the camera is the only thing that fits there). Driver's side is the R on the photo. I added the radio wire to connector # 1 plus a capacitor also on same connector. Connector # 2 has a wire coming from an aftermarket turn signal flasher which works well. The pack of red wires going to connectors # 1 and # 3 may have been accidentally swapped and placed in the wrong side. It is extremely difficult to reach this area. There is no direct vision and with so many wires getting together it is very challenging to tighten the screw that holds them to the connector. Would like some opinions before messing up more with this wiring.

In case is helpful:

- Battery is fully charged and worked great until now

- All lights work well (they have their separate circuit not connected to ignition)

- Radio works

- With a test light, I have voltage on connector # 1 all the time and when ignition key is turned on, there is voltage on all 3 connectors

- Starter motor has voltage from the battery and ground is good. Don't know how to test the wire that activates the starter from the ignition switch (this may be the key to the problem)

- Wires appear to be as shown in the wiring diagram but not sure how to test where each wire goes





I am pretty sure is a simple bad connection and my own fault for not taking a picture before adding the radio wire. Hope is not a problem with the starter (fingers crossed). Any tips? Thank you all

Manuel

 

Manual,
Take your test light and test your RED wire at starter terminal (the one that comes from ignition switch) and then while you are under hood, have someone in side car activate ignition switch and if test light comes on.

The red wire goes from ignition switch, to HORN relay, to STARTER.

Does the wiring diagram or ignition switch have numbers (1,2,3) to reference to what wires attach to ignition switch? IF SO post a photo of that.

Good Luck

Bob

EDIT: RED wire at started is number 12

Bob

 

The activation of the starter has nothing to do with the ignition switch.
On this car when you press the starter pedal down, the linkage engages the starter drive manually.
When the pedal reaches the bottom of it's stroke, the linkage contacts a large high amperage switch.
This switch is mounted on the body of the starter, and the positive battery cable is attached to it .
Other wires are also attached to this terminal, but they carry current TO the ignition switch.

Your problem is probably inside the starter, a "dead spot" in the armature perhaps.
Or the big switch on the starter is not making good contact.

 

Before you give up and pull the starter, smack the starter a good one with a rubber hammer while the peddle is engaged, like Charlie said, you may have a flat spot on the armature. This may shorten your search for the problem..Tedd

 

This is what I did based on suggestions and sadly it seems that the starter motor is dead:

1. Tested the power to coil with ignition ON and got voltage on the positive wire of the coil. With ignition OFF there is no voltage at the coil. This means the ignition wiring is correct.

2. Removed the starter switch located on top of the starter. It is a very simple connector between the battery and the starter and it looks fine to me although has a small wearing on one side of the copper connector (see photo below). This rules out a defective switch.




3. The connector on top of the starter looks fair with minimal wearing in my view (photo below). I cleaned it with a steel brush and then did a direct connection between the positive cable of the battery and the starter holding the battery cable tight to the connector on top of the starter by hand. I think I by-passed the switch with this test and I have nothing in response, just a few sparks at the negative battery terminal and not a hint of starter motor spinning









Is this sufficient evidence that the starter motor is the problem?

Tedd. I will try the rubber hammer trick tomorrow and will post result.

 

Tedd. I tried this trick but have no response. While my daughter stepped on the starter button for several seconds I gave a few blows to the top and the front of the starter motor (only areas that can be reached) with my rubber hammer. Did it a few times and did not change anything

I still don't know why my starter is totally dead. I received a suggestion to do a voltage drop test and this is what I did:I hooked the multimeter with the negative tip to the starter case and the positive to the connector where the battery cable is attached and measured 6.26 volts as expected. Then I asked my daughter to hit the starter button for several seconds while watching the voltage which immediately drops to near zero when starter engaged. I did it also with my test light and the light turned off instantly when the starter gets engaged (but no cranking at all, starter is totally silent). I repeated several times to make sure reading is accurate and got always same result. I removed and examined the positive battery cable which looks fine externally.

Can you interpret these findings for me? Is the marked voltage drop indicating that the starter motor is trying to pull current but is not getting any? I will look for a new battery cable to test again during the week if that may be the problem. I am hopeful that I won't have to remove the starter. That is a very difficult job for me, working alone with all sort of aches and poor physical abilities.

 

Just a long shot at this point. Are your battery cable and terminals clean? I have seen where the battery connection is good enough to run everything but the starter.

 

another long shot, I know it was suggested to use rubber hammer to hit starter, BUT just try using a regular metal hammer to tap starter motor as your daughter steps on starter button, MAYBE brushes inside might move enough OR armature moves a little to make contact to get around "dead spot".

ALSO
inside your starter button brass square looks melted at the right upper corner, could that NOT making goo contact?

Bob

EDIT: also try cleaning brass contact on starter where the switch makes contact, and retest with your jumper.

 

Tapping on the starter is a temporary "shadetree" fix.
When the starter eventually lands in the same spot, you will have the same problem.
Also the brushes may be totally worn out,
There may be a metal band around the starter that conceals the brushes.
If you remove this band you may be able to inspect the brushes without dis-assembling the starter.
If the brushes look OK then the starter should be removed so that the armature can be tested by an electrical shop with a "growler".
The contacts in the picture of the switch look normal. So the problem is inside the starter.

 

I am following all suggestions that I receive and appreciate everyone's comments that help a lot to learn electrical trouble shooting. Unfortunately, I still can not identify what the problem is with my starter motor. What initially I thought was a wrong wiring at the ignition turned to be a problem with either the battery, the battery cables or the starter motor. I learned that lesson from your posts so I keep focusing on sorting out which one of the 3 components failed suddenly.

Over last 3 days (nights actually, as I work during the day and then spend time in the garage late at night) I did the following:

1. Went back to the basics. Removed both positive and negative cables and cleaned them shiny and free of any debris

2. Did the same with both battery posts and all the copper connectors in the starter switch

3. Then left the battery on charger overnight



4. I connected everything again last night (must be the 15th time at least I have done it), crossed fingers and tried to crank the starter. This car has a mechanical fuel pump and typically takes 3 attempts until has enough gas in the combustion chamber to fire. I had a moment of euphoria because as soon as I hit the pedal it cranked strongly as used to be the case. I waited few seconds and pushed the pedal a 2nd time and it cranked again pretty good and the engine made the usual attempt to fire. I knew that the next time it should fire so hit the pedal a third time and............total silence, nothing, nada.

5. Again left battery in charger, just in case the battery is failing and today attempted to crank but had same outcome, no cranking.

6. I also hooked with the voltmeter to both battery posts while engaging the starter and volts dropped minimally from 6.32 to 6.26 (without the starter motor cranking). This test presumably means battery is OK

7. I noticed that the button on the starter switch located on top of the starter motor has a long path until it reaches the copper contact inside. I thought that perhaps it is not reaching the contact sufficiently and decided to fabricate a small "hat" of a copper sheet and placed it on top of the contact that is on starter (see photos below). Now when the button is pressed it travels about 1/16th of an inch only and it hits the contact on the starter, but again, no cranking.









8. Tomorrow I will use a spare 12 volt battery and connect directly to the contact on the starter. 12 volts will not damage the starter if used for a few seconds plus I will have it disconnected from the car electrical system so lights will not be burned. If the starter does not spin with 12 volts using jumper cables I will come to the conclusion that is a starter problem and will remove it.

9. I will buy a positive cable tomorrow from Tractor Supply and will try. Prefer to spend 30 dollars that may save the work of removing and repairing the starter motor. A new cable will give me assurance that the problem is or is not a faulty positive cable

Please don't get tired of my post! I am very persistent and will figure out and comments are very helpful to provide ideas.😃

Manuel

 

I think it s time to pull the starter and have the thing bench checked. With all you have done, it seems to come down to a short in the armature somewhere. Sometimes the front bearing/ bushing wears to the point the armature contacts the body of the starter and grounds out, if ran very long the starter will be ruined.... Tedd

 

When you finally decide to rebuild the starter, here's a kit that includes the armature.
Delco Starter 1107075 and 1107131 Armature Field Coil Drive Repair kit 6 Volt | eBay

 

Finally could resolve starter problem successfully !!


Found a 2/0 (00) cable at Fleet Farm store. Before installing it I hooked a spare 12 volts battery directly to starter and it worked perfectly and confirmed the starter motor is fine.


Then I installed the new positive cable and the motor started spinning happily. It is a 24 inch long cable and a few inches longer than correct but I don’t mind if it does the job well. It is good quality copper.




In conclusion, careful cleaning of ALL contacts plus new cable resolved the “dead starter” problem.

Thank you all for your replies and suggestions. You made the job a lot easier!!!



Manuel

 

Glad to see you have it working. You should still inspect your brushes to see how worn they are. This is very simple, that thin metal band on the end of the starter is an inspection cover. You unsnap that cover and you will be able see what condition your brushes are in. If they are worn down almost to the bottom your started should probably still be rebuilt. If you have a lot of brush left it will probably last as long as you will ever need it to.

 

I see the metal band you mentioned is held by 2 screws. Do you know if after I removing the band, is there access to inspect all brushes or is enough to see one of them and assume the others are the same? Only one side and the top of the starter are visible, so I presume will not be able to see some of them unless the starter is removed, which I am not eager to do because is a difficult job for me due to physical issues. Once is out, I can learn how to fix one but have no shop equipment to test.

Thanks for your comment!

 

After the band is removed, all the brushes can be inspected with a small mirror and a flashlight.
They all should wear evenly, but there's no guarantee that they will.
Also check the springs that hold the brushes to the commutator.
If they are weak or broken, It will cause erratic action.

If the starter continues to have problems, I would recommend that you have someone remove it and take it to an electrical shop where they have the proper equipment to test and repair it.

 

@Doctor Olds Good stuff you have posted here from start to end.

Bob