Solenoid/starter not engaging when rain or high humidity

[csearider]

1940 LaSalle - Solenoid/starter not engaging when rain or high humidity

Works fine in dry weather...Local Auto Electric guy is stumped...

Anyone with experience with this situation?

6 v starter/8v battery

[Spinneyhill]

Sounds like poor connections to me. If the car has brass terminals on all the wires and all those terminals are zinc plated and attached to a steel bolt with steel washer and nut (which are probably rusting), you have a wee galvanic cell at each connection. Zinc oxide doesn't conduct much. I know this because I had 2 V at the coil in my Studebaker before cleaning all the terminals. That is where I would start looking.

[csearider]

That is most logical and have done this several times...but, will do again on your advice.

Note: starter and solenoid is original, but professionally rebuilt

Also, vehicle has been complete new wiring harness from AZ and was professionally supervised by TRAACA car club

Also running Pertronix ignition, but did same before it was installed

Note 2: Rained for 5 days off and on with popups and no start any day....did not rain today and 4:00pm removed light bulb from starter area (This will help starting when humid) and immediately started up....)

?????? if it rains tomorrow it will not start guaranteed!

Thanks Spiney!!!!!!

[Spinneyhill]

When it won't start, is it worth going around and testing resistance across connections and voltage at those connections?

 

When the solenoid and starter were rebuilt, did they use new wire inside?

 

When you say won't start, what actually happens?  Solenoid doesn't even click? Is there a good electrical connection between solenoid and starter = earth?

Edited July 23, 2018 by Spinneyhill (see edit history)

[csearider]

 Voltage 8.5v at solenoid

The solenoid only clicks and loud enough to hear it click inside the cab. So solenoid not allowing starter to engage

Starter was rewired when rebuilt

 

Next step: will verify hot solenoid connection from battery (test light to each terminal) When verified will run wire to battery cable connection on starter from hot solenoid terminal and see if starter turns over....

 

just for info the system is positive ground

 

The test make take a few days as push button start so will need to put wife in car to push button before she goes to work...(that will be lots of fun!.Ha!ha!)

 

stay tuned!

 

[TerryB]

Battery ground good?  Is there a ground strap from body to frame?  Is the ground of the solinoid clean and tight?

[1937-44]

 This might sound like a dumb idea but I'll throw it out there anyway. When it's wet and not cranking over what about putting a hair dryer to the connections one at a time. Get one connection nice and warm to dry it off, try and start the car, proceed to the next connection.

[TerryB]

I’m thinking it’s the brushes in the starter not making good contact.  Water can be an insulator in low voltage circuits.  Most time we think of it as a conductor but that only happens in high voltage like coils and spark plug wires.  In low voltage, water can make corrosion that impedes the flow of electricity.  Your comment about the light bulb near the starter is what led me to this thought.  The brushes and their contact area on the starter armature are suspect.

[Spinneyhill]

Yes. And is there a good connection between the solenoid and the starter and the wires inside the starter are not near the case of the starter where voltage leakage might be occurring in damp conditions?

[old car fan]

I think ground,frame to starter bolt.maybe wrong

[Gary_Ash]

Let your wife go to work:  buy a 6 volt starter solenoid as used in old Ford 8N and 9N tractors as well as 1950-ish pickups.  Tractor Supply stocks them (cheap).  These have a button on the bottom for manual actuation.  Great for situations like this and when setting timing.

 

see https://www.tractorsupply.com/tsc/product/tisco-starter-solenoid-nca11450a?cm_vc=IOPDP1

 

Edited July 24, 2018 by Gary_Ash (see edit history)

[csearider]

is this compatible with a GMC starter?

[Ben Bruce aka First Born]

Yes, the solenoid does not know one car from another.

 

  Ben

[Tom_S]

Checking for voltage at connection points does not solve the problem.  It is the amperage that is needed to start.  You can have proper voltage measured my volt meter, but if the proper amperage is not getting to the starter then it isn't going to start.  Resistance could be building up in connections due to corrosion, etc.  I have a tractor that has that problem and every so often I have to go thru all the switch connections, etc. to start properly.  This even though I put electrical grease on connections and shed kept. 

[csearider]

Makes sense!...will do all that again....

[Spinneyhill]

Make sure there is no paint under the connections too!

[csearider]

On 7/24/2018 at 5:57 PM, old car fan said:

I think ground,frame to starter bolt.maybe wrong

This is right on what I been thinking......last two days saying to myself..."Crawl under her and grind some surfaces"......Thought also need the best elec conducting bolt and nut.....suggestions?  (strap is new)...

[c49er]

Was the starter painted where it bolts to the bell housing... causing a poor ground?

Did you tighten each wiring nut?

 

 

[Spinneyhill]

It won't have an impact on this problem, but is your earth strap designed for 6 V or 12 V? The 6 V straps (ground and -ve) need to be bigger than a12 V strap because you need more current.

 

You should have 00 = 2/0 AWG = 0.3648 in. dia. cable.

Edited July 26, 2018 by Spinneyhill (see edit history)

[GLong]

Having only a strap type ground from the battery to the chassis is not enough.  Make a dedicated ground CABLE from 1/0 or 2/0 welding cable.  Solder the loop ends on the cable.  Put one end on the pinch bolt of the grounding battery clamp, and put the other end under the head of one of the starter-mounting bolts.  Use a star washer between the cable end and the starter-body or mounting ear.  

 

When you are experiencing a humidity-related no start, you said you can just barely hear the solenoid clicking.  I'll suggest that the solenoid has some dry dust from the starter brushes or road dirt on the moving parts: the piston moving inside the electromagnet of the solenoid.  When damp, the dust is more like mud, and is causing the solenoid to move slow, with low energy, and it can't close the contacts.  I'd take the solenoid off, and apart and make sure it is perfectly clean inside.  

The Tractor supply solenoid is a great idea. 

 

GLong

[csearider]

A new Positive ground battery cable was next move.......2nd cable to stqrter mounting

bolt an extra good idea

Thank You!

[trini]

If yours is made with material like the distributor cap , the chances are that there may be a tiny crack somewhere in the material near a terminal. When the weatheris damp current leaksto ground. Try cranking when it is dark. Have someone look while cranking for streaks of fire.

Fords of the late 1960 was famous for cracked caps when it rained overnight.. Worth a look.

Harry   

[54vicky]

little late but moisture will wreak havoc if battery posts and connection are not clean shiny clean.dealt with it many times over almost 60 years even new battery with out clean again shiny clean and tight no problem till damp

Edited August 30, 2018 by 54vicky (see edit history)

[csearider]

On 8/18/2018 at 11:39 PM, GLong said:

Having only a strap type ground from the battery to the chassis is not enough.  Make a dedicated ground CABLE from 1/0 or 2/0 welding cable.  Solder the loop ends on the cable.  Put one end on the pinch bolt of the grounding battery clamp, and put the other end under the head of one of the starter-mounting bolts.  Use a star washer between the cable end and the starter-body or mounting ear.  

 

When you are experiencing a humidity-related no start, you said you can just barely hear the solenoid clicking.  I'll suggest that the solenoid has some dry dust from the starter brushes or road dirt on the moving parts: the piston moving inside the electromagnet of the solenoid.  When damp, the dust is more like mud, and is causing the solenoid to move slow, with low energy, and it can't close the contacts.  I'd take the solenoid off, and apart and make sure it is perfectly clean inside.  

The Tractor supply solenoid is a great idea. 

 

GLong

 

[csearider]

Great idea.....In case I did not mention it is positive + ground.....negative battery cable goes to the starter.....therefore + positive battery post cable to chassis............and as you mention to the starter mounting bolt.......

 

I will begin by replacing existing + positive ground cable to chassis.....then add the additional + cable to starter mounting bolt.....see what happens.....and if need be..... replace starter cable itself  and then engine mounting strap....

 

Starter and solenoid were previously professionally rebuilt and taken back and re-examined when first started....but will repair/replace solenoid if necessary.......

 

Csearider .......maybe change nickname to "ShadeTree"...!!!!

[Spinneyhill]

4 hours ago, csearider said:

.maybe change nickname to "ShadeTree".

Too late! already taken.