Bad starter solenoid confirmation?

[aquifer]

67 beetle. My research on the forum leads me to believe that I may have a bad starter solenoid, but I want to verify before I replace anything. The starter is original to the car, and I had it professionally rebuilt several months ago. The rebuild included a new solenoid. It worked fine until recently. New battery a couple months ago, tests 12.7 volts at rest.

Here’s what happens: I turn the key to the start position and nothing happens. Nothing at all, no click, no starter spinning. Usually I can turn the key off, try again, and it works fine. But twice now, that was not the case. It would not do anything at all no matter how many times I tried the switch.

The first time it happened, and “trying again” didn’t help, I jumped the wires at the ignition switch and the starter engaged normally, and the engine started. I thought, ok, the switch is probably going bad. That was maybe a month ago.

Since that time, it has started normally almost every time, but always started on the “try again” with the key a couple times when it acted up.

But today when this happened again, I tried jumping the ignition switch and no dice. Same 12.7 volts at the switch at rest. I turned on the lights - they are bright and normal. I left them on while I tried the key again, and they dimmed slightly - very slightly - and the starter didn’t do anything. No click, no spin, nothing.

So we push started the car and I drove it to my garage/shop and I shut it off. Tried starting it with the key and it started normally. Tried this 2-3 times and it started normally each time.

The fact that it wouldn’t do anything today when I shorted the ignition switch leads me to believe it’s probably the solenoid and not necessarily the switch, but I don’t understand why it’s intermittent.

What do you think? Thanks in advance.
_________________
Parts needed:
Front & rear NOS or used OEM door panels for a '67 in the original Gazelle color (dark tan/light brown).
Also looking for used white headliner pieces, both perforated and non-perforated.

[mukluk]

Could be something simple like a loose connection at terminal 50 on the starter solenoid (trigger wire from ignition switch).

IMO, the best thing to do here is first verify that all the wire connections at the solenoid and ignition switch are clean and tight, then verify with a volt meter that you are consistently getting good voltage at the solenoid terminal 50 when the ignition switch is turned to start. If the voltage is low, find and fix your voltage drops in the starter/switch circuit.

If your voltage checks are good after doing the previous and the problem reoccurs, make absolute certain the trans is in neutral and the parking brake set, then manually jumper the 30 and 50 terminals together at the solenoid with a screwdriver to see if the solenoid clicks or the starter operates. If manually jumping doesn't get any response out of the solenoid, then it's bad.
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1960 Ragtop w/Semaphores "Inga"

[Bobs67vwagen]

Aquifer if the solenoid checks out good, a possibility would be resistance build up on the wire from the switch to the starter. I had a 66 that had this same intermittent problem. My solution back then(a long time ago) was to put a momentary switch in the kick panel in front of the battery. I wired one side to the battery and one side to the starter. When my switch acted up I would leave the key in the on position, reach behind the seat and hit the button and it would start every time. I am not saying you should do this but you could set up one of those under hood remote starter devices used for cranking an engine over while working on it to see if your problem is in that line. Did you replace the starter bushing when you did the starter? Good luck bob

[aquifer]

Good advice here, thank you both. I will do more testing. I will get a helper to run the ignition switch while I take a voltage reading at the solenoid. I hadn’t thought of that. It’s up on the lift anyway because I’m putting on new tires, so it’s about as accessible as it can be right now for me.
_________________
Parts needed:
Front & rear NOS or used OEM door panels for a '67 in the original Gazelle color (dark tan/light brown).
Also looking for used white headliner pieces, both perforated and non-perforated.

[Eric&Barb]

Could be bad:

1. Starter solenoid.

2. Wiring connections from the battery to the dash and back to the starter solenoid, loose, corroded or even junk terminals used that build up corrosion between each wire and terminal. Stock terminals are gas tight when installed with a factory style ratchet crimper. So no water or oxygen can get into there.

3. Dirty, corroded or even painted over grounding areas of both the starter and starter solenoid. Also would pull off the ground cable from transaxle and body for a good cleaning of all surfaces and again use dielectric grease to seal those connection from future corrosion. Same for both battery cables on BOTH ends. Do post an image of the battery cables at the battery. Too many folks running bolt onto the cable battery clamps that make for additional connection for corrosion and due to right next to an acid sweating battery.....

4. Failing ignition switch.

With the transaxle shifted into neutral. Parking brake pulled up. Slide under the beetle just forward of the right rear tire, short from the terminal that the positive battery cable is attached to over the small terminal the wire (pull wire off for testing) from the ignition switch goes to engage the starter.

If starter engages fine, then you have something wrong in the wiring between the battery, ignition switch and back to the starter solenoid. Either way next step will be to check for voltage drops, and exercise those out of the wiring. Any voltage drops need to be removed so you have brighter lights, faster wipers, and a good loud horn that works all the time. Not fixing all voltage drops means you can not see as well and other drivers might not see you as well, resulting in a crash that could have been avoided.

If starter still has a problem engaging you could have a bad starter solenoid, and/or bad grounds between starter solenoid and starter and/or starter and transaxle. The last two need to be sanded clean of any paint, dirt or corrosion and apply dielectric grease to those surfaces to seal out future water and oxygen from causing corrosion for as long as possible.
_________________
In Stereo, Where Available!

[zerotofifty]

get a volt meter on the solenoid and see what you got upon starting attempt.
test terminal 30 on the solenoid to the solenoid case. if low, but you have a good battery, then that means you got high resistance someplace.

fact that she is intermittant does lead one to suspect the key switch. as you get no click at all when she dont work.

but be mindful, you may have many marginal connections, if say the connector at the solenoid is dirty, the battery terminal,is dirty, the ground strap,is dirty, that can add up to a marginal voltage, but workable, but then you also have a flaky key switch that once and a while is high resistance, but if all else was perfect will not be a problem ever, but since there is other high resistances in the chain of the electric path, some times it wont work. a hard start relay can help by it by passing a lot of the old dirty connections, and long wire paths

you got a path from battery plus, to the regulator, to the headlamps switch, to the key switch to the solenoid. bad connections or crimps in the path can give big drops in voltage, add to that a poor contact within the key switch, and it means failure a hard start relay bypasses this as the relay draws little current, your long path and old connections can handle it.



consider a hard start relay addition. That way you can maybe keep your existing key switch.

if you do have good voltage, the solenoid may have become sticky, they can oft be freed up.




https://www.thesamba.com/vw/archives/info/wiring/bug67.jpg
_________________
Sorry About That Chief.

Give Peace a Chance.

Words to live by.

[indianpeaksjoe]

I installed the Wolfsburg West Hard Start Relay in my 66 and it was quite easy: https://robonza.com/beetle/index.php/2024/05/23/hot-start-issue-part-iv-hard-start-relay-install/

-Joe
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Adventures in owning a 66 beetle

[aquifer]

To start my diagnosis, I'm going to check the voltage at the wire on the solenoid coming from the switch. Obviously, the switch has to be turned to the "start" position, so I'll need to phone a friend.

The question I have: If I pull the wire off the solenoid I can check voltage without the starter trying to engage. Is that acceptable, or does it need to be connected? I ask because I can envision there being a voltage drop if the starter engages. Is that true, or should there be no drop in voltage even if the starter engages?

I did not replace the ground strap from the transmission to the body when I had the transmission out for a rebuild. Everything was clean, but the strap itself was pretty tarnished, and there may have been paint on the body and transmission surfaces, any of which might be preventing a good quality ground connection. I'm going to do one test at a time, starting with the voltage test I mentioned, and go from there.

Thanks for the good advice on this.
_________________
Parts needed:
Front & rear NOS or used OEM door panels for a '67 in the original Gazelle color (dark tan/light brown).
Also looking for used white headliner pieces, both perforated and non-perforated.

[Eric&Barb]

[mukluk]

x2, you need the load when testing, otherwise you can miss possible issues with burned contacts and damaged wires. Leaving the wire connected also affords the opportunity to catch the no click/response issue you're trying to troubleshoot.

Expect to see some voltage drop while the starter motor is running, but it shouldn't be more than about two volts. You can get a baseline of the expected drop by measuring voltage across the battery terminals and operating the starter a couple times. Ideally, when subsequently checking the voltage getting to the solenoid from the ignition switch the voltage will be not too much less than battery voltage and consistent each try.
_________________
1960 Ragtop w/Semaphores "Inga"

[aquifer]

Many thanks, both replies make perfect sense to me. Does it make sense to unplug the coil wire so the engine doesn't actually start? I'm thinking that might let us run the starter for a few seconds to get a good reading. Usually the engine starts right up when the starter spins, so this might be the way to go? I'm not going to crank away on it endlessly, but just for a few good seconds.
_________________
Parts needed:
Front & rear NOS or used OEM door panels for a '67 in the original Gazelle color (dark tan/light brown).
Also looking for used white headliner pieces, both perforated and non-perforated.

[mukluk]

Disabling the coil during testing would be a very good idea. If you still run points ignition, the best method IMO is to disconnect the green distributor wire from the coil's negative post. This will allow you to leave the ignition switch on if need be without concern for burning up the points or coil.
_________________
1960 Ragtop w/Semaphores "Inga"

[Eric&Barb]

[zerotofifty]

[aquifer]

Here are the results of my voltage tests. Not sure what I’ve learned, so I’d appreciate your thoughts.

Voltage at the battery, at rest, car not running, key turned off: 12.65
Voltage at the battery while cranking the engine: 11.50
Voltage at the solenoid, on the wire coming from the ignition switch, while cranking: 10.90

For the solenoid test, I grounded the lead at the bolt on the transmission where the braided ground strap is. I then put the lead on the chassis bolt at the other end of the strap and cranked again. I scratched the lead into the paint so it made good contact. In both locations there was no appreciable difference from the 10.90 voltage while cranking.

I kept all wires in place except I disconnected the condenser wire at the coil so it wouldn’t start. I don’t think that would have any impact on the voltage readings.

So with this information, what do you think?
_________________
Parts needed:
Front & rear NOS or used OEM door panels for a '67 in the original Gazelle color (dark tan/light brown).
Also looking for used white headliner pieces, both perforated and non-perforated.

[mukluk]

The numbers sound decent considering the length of the starter terminal 50 circuit.
_________________
1960 Ragtop w/Semaphores "Inga"

[zerotofifty]

The 10.9 volt at the solenoid when cranking is good, however we need to see what the voltage is at that test point when she fails to engage the solenoid.

when she fails to have the solenoid engage, that voltage will either be close 10.9 volts, or it will be considerably less.
If around 10.9 volts and the solenoid does not engage, then the solenoid is suspect of being bad.
If the voltage is a lot less than 10.9 volts, then the number one suspect is the ignition switch, or any hard start relay that you may have on your car.

So you need to test her with the solenoid failing to operate, or "click".

Oh the joy of intermittent failures. you need to continue to test until you get the failure, and record the voltage when she fails.

You either have an intermittent sticky relay or its internal coil, or an intermittent key switch, or an intermittent hard start relay if so equiped. those are the three most likely option as of now.

So keep testing until you get a fail, record the voltage during the fail.

good luck
_________________
Sorry About That Chief.

Give Peace a Chance.

Words to live by.

[Eric&Barb]

You should get rid of at least a half volt of drop. With longer wiring harnesses in the buses we have, been able to get voltage drop to less than 1/10 of a volt.

Would also clean up the grounds as previously mentioned.
_________________
In Stereo, Where Available!

[aquifer]

Thanks again for all the advice & knowledge.

I'm going to shine up the ground strap studs/surfaces and replace the ground strap from the transmission to the chassis. I had put new battery cables on when I replaced the battery, but I don't recall if I spent much time shining up the surface where the negative cable bolts to the chassis. So I'll revisit that and make sure it's shiny too.

I'll also disconnect the wires from the ignition switch and shine up the terminals. Then I'll take new readings and see how it acts after that. I may end up replacing the solenoid, but these things need to be shored up anyway, so I'll start there.

I need to pull the radio out to work on the wiper arm & motor, so I'll just make a project out of it and shine up the wire terminals on the switches too while I'm in the mood.
_________________
Parts needed:
Front & rear NOS or used OEM door panels for a '67 in the original Gazelle color (dark tan/light brown).
Also looking for used white headliner pieces, both perforated and non-perforated.

[Bobs67vwagen]

I would be interested when you do finally find out the cause of this is, what is was. Hard to top all of the great troubleshooting advice you received on this topic. My guess would still be the ignition switch or the wire from the switch to the solenoid. Good luck-Bob