1942 BUICK STARTER ISSUE

[ILIKECARS53]

Hi All,  It has been awhile.  My first Buick project in the new garage.  Will have to send some updated pics of the garage.  But getting back to the issue with the Buick. It is a 1942 Buick Limited with the 320 engine. It has the dual carb setup with Carter WCD's front and back. The problem has been going on for about 2 years, but just getting to it now since I have a very nice place to work.    When I would try to start the car the starter would just click.  I thought it was the battery, but that did not solve the problem.  Then I thought it was the vacuum switch in the carb. I bypassed the switch by touching the wires together, still nothing.  Pulled the starter and cleaned the contacts of the solenoid and checked the gap, still nothing.   Then I tried to start manually by touching the contacts  and  it started right up. This is how I have been moving the car around for the past 2 years.  It is a little awkward.  This past week I pulled the starter again and rechecked everything and again cleaned the contacts.  Pulled the vacuum switch and cleaned it.  Still to no avail. I left the cover off the solenoid and touched the contacts  and  it started right up.   Am I missing something.  What else could I check.   Thanks  Jim

[1939_Buick]

Download the 1942 Buick shop manual for free. All of it section by section.

Or click the pdf link to pay.

http://www.oldcarmanualproject.com/manuals/Buick/1942/Shop Manual/

It is very comprehensive and has information that can be used with all straight 8’s.

It has more information than was included in older “Shop Manuals” before 1942

 

Reads like an electrical problem. Are cables grounded?

http://www.oldcarmanualproject.com/manuals/Buick/1942/Shop Manual/13 Electrical System/index1.html

 

Edited June 5, 2021 by 1939_Buick (see edit history)

[Rock10]

What contacts are you touching?

 

[Bloo]

The copper bolts in the solenoid are the likely culprit. Clean is nice, but if they look like they lost a lot of copper they probably don't reach anymore. There is also a relay on the back of the starter on many of these setups. The points could be dirty. and need a gentle cleaning.

 

For what its worth, its almost always the copper bolts. Sometimes you can turn them backwards to get a new taller surface if someone in the past has not already done it.

 

I second Rock10, what contacts? That could tell us a lot.

Edited June 5, 2021 by Bloo (see edit history)

[ILIKECARS53]

Hi everyone,  

 

Here is the starter and solenoid.  The cover is on the solenoid.

 

 

Under the cover is the contact.  When I touch the contacts together the starter engages and the car starts.

 

 

Based on this,  I believe it is not the starter nor the solenoid.  I could be wrong.  Also when I jump the wires at the switch at the carb, nothing happens.

 

I cleaned the contacts. Based on the manual the contact gap  and  air gap were right on.   I took the solenoid apart  and  shined up the copper bolts  and  washer.

 

 

When I press the plunger in manually,  the washer makes good contact with the bolts.

 

 

 

Any other ideas would be appreciated.   Thanks   Jim

 

 

[Matt Harwood]

Do you have continuity in all the wires? Perhaps the signal to trigger the solenoid isn't getting there.

 

Also, I believe the starting system has a secondary check for voltage (meaning the generator is spinning), so the starter won't engage if the generator is making current. I don't recall how that mechanism works, but it's a back-up system to ensure the starter isn't damaged by engaging on a running engine. Is there a short somewhere?

[Bloo]

Somewhere, but not in your pictures, are 2 small terminals for small wires. They go to the relay coil that pulls those small contacts together. One wire comes from the vacuum switch and supplies 6 volts. The other one comes from the charging system and provides a ground.

 

To get any deeper than that I need a 1942 wiring diagram (and I don't have one). Do you have one?

[Rock10]

As Bioo said, the relay should close those contacts. Does it click when you jump the manifold switch?

With 6V applied to the solenoid terminal from the manifold switch(and the starter grounded) the coil in the solenoid should pull the contacts together and push the pinion into the flywheel. If nothing clicks, my bet is the coil is bad.

If you know this I apologize:

The round can is an electromagnet. There is a steel plunger inside that the magnet pulls up when energized. The plunger closes the contacts and pushes the pinion. The magnet coil could be bad or the plunger stuck.

Edited June 8, 2021 by Rock10 (see edit history)

[Bloo]

But keep in mind that since this particular solenoid has a relay on it, with a floating coil, there are TWO terminals. You not only need the 6v to one terminal, you need the ground to the other or it won't trip. Both the 6v and the ground are interrupted while the engine is running. The 6 volts is interrupted by vacuum, and the ground is interrupted by the charging system. It's sort of a "double safety" to keep the starter from engaging with the engine running.

Edited June 8, 2021 by Bloo (see edit history)

[37_Roadmaster_C]

@Bloo is exactly right.  If the wiring harness is factory original there are two smaller wires that connect to the solenoid. One is black with parallel tracers which goes from the starter solenoid to the Vacuum starter switch on the intake manifold. This wire should have Positive 6 volts when the ignition is on and the throttle is pressed (engine not running). The second wire is Green with crossing tracers. This wire connects from the solenoid to the A terminal on the voltage regulator. This provides the ground for the solenoid via the generator armature when the generator is not turning and therefore not generating.

There are some simple tests to get you started (no pun intended) with a simple test light. First with the test light clip connected to a GOOD ground place the probe on the small terminal with the green wire. With the ignition on work the throttle to activate the vacuum start switch. The light should light up. If it does the starting circuit and switches are good and working properly. If it does not light there is a problem between the ignition switch and the solenoid. Assuming the light lights, do the same test with the probe on the small black wire. If the light lights this time there is a problem between the solenoid and the generator as the generator armature provides the ground for the solenoid to operate. If the light does not light and the solenoid does not operate the problem is the solenoid.  Below is a link to the wiring diagram for your car. Good luck and keep us posted!!!

 

1942 big series wiring diagram

 

 

 

Edited June 9, 2021 by 37_Roadmaster_C
clarification (see edit history)

[ILIKECARS53]

Thanks to all.  Will try the procedure outlined within the next day or two  and  will let everyone know.   Thanks  Jim

[ILIKECARS53]

HI All,  My neighbor came over to give me a hand taking off the hood.  We all know what a pain in the butt it is to working on a Buick that has the dual hinge hood. He stuck around a little while and gave me a hand diagnosing the problem. Started at the beginning. Bench tested the starter.    No problem.  Then did the same to the solenoid.  No problem.  Put the starter in the car and reconnected all the wires at the starter and carb switch.  Nothing.  Started doing the checking that Robin outlined.  All was going well until the generator wire check.  The wire was not making good contact at the generator.  It looked connected and did not go further when I first encountered the problem.  I called myself every name in the book.  Bottom line to all of this, the car started has it should.  Now onto the next issue.   Thanks to all for the help.    Jim

[Rock10]

Great!

 

[Joseph P. Indusi]

Thanks for posting your solution to the problem. 
Joe, BCA 33493

[37_Roadmaster_C]

@ILIKECARS53,  I am glad you got it fixed. You actually fixed two problems. With that bad contact the generator would not be charging properly so you fixed that also 🤭!!