Starter troubleshooting
 

I have read on lot on the forums and done a lot of work and am still stuck. I may just be having bad luck but if there is any test I can do before I start buying and replacing I am hoping I can find it here.

The problem is intermittent starting. It either starts up perfectly and quickly. Or the solenoid clicks loudly but the starter does not turn at all. Battery has been tested and swapped. Starter has been replaced. Wiring has been tested.

All I can figure is that the solenoid contacts are not making a good connection...sometimes. Very frustration because it will usually work fine. But then it doesn't and you are stuck. It happens with the engine hot or cold. With the ambient temperature in the teens or in the eighties.

Short of replacing the battery, starter (again) and all wiring what can I do to actually figure out what is going on?

I had a similar issue once, turned out that I had gotten a bad rebuilt starter. Other than that check all the battery leads. They can corrode internally and cause high resistance.

Problem could be in your neutral safety switch if it acts up you could try jumping it on your fender well if it starts that eliminates that. See if the starter is getting voltage if so jump it. I ounce had a problem with intermittent starting before I traced all wires and voltage to starter finding that there was a broken small wire at the tip where it connected to starter and it would work and not work. Went thru many starter installs for nothing till I figured this out finally.

How many starters? Were you pissed not doing the easy stuff first?

Remember, this is a long distance diagnosis so all bets are off as far as guaranteed accuracy......

That said, it sounds like the starter has a bad commutator segment. In the olden days we'd use a gizmo called a growler to check each segment for connectivity as a part of the starter rebuild process. In the days before commercially rebuilt components were commonly available shops like the Buick dealer that I worked for did on-site rebuilds so we could save the customer some money and get them back on the road. If there's an open segment in the commutator (that's the part that rotates) the starter will work fine until it happens to stop with one of the brushes sitting on that bad segment then no connectivity = no rotate.

EDIT: If the neutral safety switch was bad there would be no solenoid click when you turn the key. The NS switch stops all power from initiating the start process so the solenoid would never try to click. So while a no-start should include a look at the NS switch, if the solenoid clicks, that ain't it.

If you have a decent local rebuilder of such components (we have Coastal Rebuilders here in Wilmington) they can test the commutator and tell you for sure if that's the issue. If not you're sort of stuck with taking the starter back to the store where you got it and trying another one until you find a good one. Other than being stuck with the effort to remove and replace it, that may be your cheapest option.

BTW - I patronize our local shops (Coastal Rebuilders, a local transmission shop, local car audio shop, etc.) as much as I can partly because I get good work and partly because they're a great resource and I want them to be around in the future. I'd suggest that you at least consider the same approach.

Dan

When it clicks and fail to start, jumper the terminal block (big screw to small screw) on passenger wheel well. If it starts every time with the jumper, problem could be anywhere from the ignition switch, NSS, all the connections and wiring in between. I'd start by cleaning all battery terminal cable connections and the ground strap on drivers side from bell housing to frame and see if that helps first.

I recently went through this in my SDL. PO had installed a newly rebuilt starter 2 days before I took the car home. Worked perfectly every time I used it for the last year, then suddenly started this business where you'd hear the solenoid click, but no starter. Cycle the key a couple times and usually it would pull in and the starter would fire, until one day it stopped clicking, though you could tell it tried to do something because the dome light would dim slightly.

Pulled the starter and opened it up. Whoever did the rebuild had slathered the plunger on the solenoid with axle grease. Big no-no. In time it gummed up and wouldn't let the plunger move. Stripped it out and it's been fine since.

The solenoid has to make full-travel in order to close the contacts for the motor to run. If there's anything in there that prevents it from bottoming out, the contacts aren't gonna close and the motor isn't gonna spin.

Wiring
 

Definitely not the NSW. That was my first thought because that has always been the problem before. I replaced it with a new Mercedes switch and thought I had it fixed for a week or two. That is how random this problem is.

I just disconnected all the wires. Everything looked fine. Old but no obvious issues. There is just the smallest amount of corrosion on the starter end of the small wire that activates the solenoid. See attached photo. I think I will replace this wire with new.

I am skeptical of this being the problem though. The solenoid never fails to make a strong clunk sound. Could lowered voltage due to resistance through this wire be enough to keep it from engaging the contacts firmly enough. Should I increase the wire gauge? Does this wire get power directly from ignition switch. I could add a relay on the fender in order to feed more amperage to the solenoid?

Pretty sure the problem is not before the connections on the fender because it happens no matter wether I use the key or remote starter straight from the battery.

check engine ground,or add another.I always add extra grounds to my vehicles.They charge better.

That makes sense. This problem started on what I believe was the original starter and then again on a good used starter. Did not go more than a few days without starting again so it makes me suspect something outside of the starting cause the lack of contact.

Just trying to elimate every other possibility before I remove the starter again.

It never has a problem cranking and I checked ohms between negative battery terminal and block. Where would you add a ground (location on engine)?

I feel like a ghost hunter here or something. I hooked up voltmeter between lugs on solenoid and fed power straight to trigger lug from battery with remote start cables and every time I press the button the voltmeter ohms zero out immediately.

Really hard to diagnose when the problem hides for days at a time...

When it clicks but not spin the engine, did you try banging on the starter with a big iron pipe or equivalent? If that gets it spinning, that could indicate worn brushes or cracked solenoid housing plastic where the terminal stud/nuts are. Some people over tighten the nuts, cracking the plastic resulting in the copper shorting bar not make good contact anymore. Those nuts make an electrical connection, not mechanical. Make them just tight enough so the nuts do not come loose.

Ditto on check engine ground. Once when I had the cluster pulled out in my 1985 300D, I actuated the starter (forgot why) and noticed the speedometer cable smoking. That clued me to sand the connections on the ground strap from transmission to body, then coat w/ silicone grease. There is also a ground strap from BATT- to the frame. If it is a voltage loss issue, you could find where using a multimeter while trying to crank. All the starter cares about is the voltage from its case to the big stud +12 V feed. If >8 V while cranking, a good starter should work. You could have excessive drop on either side. The solenoid is integral to the starter (unlike 60's Ford), though I think can be unbolted.

I am going to clean the engine ground strap just for the heck of it but I think that the problem is internal to the solenoid. I took all the wiring to the starter out and looked over it. Everything looked good and I made a new trigger wire from the fender to the small connection on the solenoid. Cleaned everything really well put it back together with dielectric grease and it started right up. Drove it 50 feet turned it off, tried to restart it and just a clunk.

One trick seems to work. If I connect my remote started button at the fender and press it in rapid succession it will catch and sometimes I can even hear what sound like a little electrical sizzle right before it goes. After that I can start it right up with the key

Would a bad ground cause this?

Is it possible that the voltage from the key is too low?

Could I add a relay to get more juice to the solenoid?

If I replace the starter with new should I also replace the battery just in case?

Thanks for all the help so far!

Measure voltage and current for the solenoid. Solenoid should draw around 7 to 8 amps. Use the ground at the starter and not at the battery for a true reading the starter is seeing. I am not sure what voltage you should get but my guess around 11 to 12 volts if it just clicks and starter does not spin. If it spins, you'll see lower voltage due to higher current draw, my guess 8 to 10 V. If your key switch contact is marginal, i.e. higher resistance than normal, it will reduce the current drawn of the solenoid. If you measure only 5 amps for example, it could be a bad key switch, or a bad starter ground, or bad wiring in that circuit.

That all makes sense except sometimes it works and sometimes it does not. What is changing? I can do some more testing but still confused on why it is intermittent?

I think I answered that for you, or at least gave you a reasonable possibility. When you wack it, BTW, you can jar the commutator just a tad so that the dead segment is no longer contacting the brush and then it works until the next time it lines up - completely random. I understand that you don't want to pull the starter back out but think about your symptoms and who's suggestions make the most sense.

Dan

I have one of these gadgets, if you want to borrow:

Model 8540 | Associated Equipment Corp.

It will tell you whether the battery is holding up under starting loads and simultaneously tests the grounds, starter power connection, and the solenoid lead. It works by measuring the voltage drop at each connection. Someone gave this to me as a gift, I've never had reason to use it.

FWIW, I think Dan's nailed it. A fouled commutator or one open winding would behave like this.

Here are a couple photos of the old starter solenoid:

It looks like material got transferred from the lugs o the connecting plate over time. Don't know if that's normal or not.

As far as current and voltage go... if it is just clicking and I connect the solenoid trigger wire to positive battery it still clicks.

It is only after several rapid clicks that I can get it to make a good enough connection to turn the starter over. Once the connection is made the engine turns over quickly and starts immediately.

Did you bang on the starter with an iron pipe as I suggested in #12?

You either have a solenoid that isn't pulling in all the way (far enough to close the contacts in the switch it pulls against), or you have a failing relay switch (burned points, warped contact disc, etc).

If the solenoid is pulling in with enough force to clunk you don't have a wiring issue. The solenoid itself pulls somewhere close to 20A all by itself, meaning your ground should be ok and the wiring to the solenoid should be ok as well.

You either have a sticking solenoid (pull it and see if it's been greased), or you have a set of contacts that's failing that the solenoid pulls in against. Either way Funola's suggestion of slapping the starter with the iron pipe should get it to pull in enough to operate if that is the problem.

I had this happen. Went through same frustrating starter replacement and pipe banging. Finally noticed smoke at battery connection. Probably checked contacts already three times through the process. Dissolved the corrosion until copper was clean. Put it back together. Problem solved...for years now. That's my guess.

Did you change the solenoid when you changed the starter?

Is your new starter a rebuilt one? If so, who rebuilt it?

The starter I put in was a used one a got from a car I parted out. It looked newish (clean black paint) but no Bosch sticker.

I definitely suspect the problem is the contacts inside the solenoid.

I am close to ordering a new Bosch starter to fix the problem.

My concern is that the good used starter worked fine it first and now has the same exact symptom the previous starter had.

So it's either coincidental bad luck or some unusual problem somewhere else in the extremely simple electrical system.

Just to be clear : when the starter will not turn over it never fails to produce a consistently strong clunk sound of the solenoid engaging. When that happens with the key and I jump it between the screws at the firewall connection same exact result. If I connect directly from battery positive to solenoid same exact result.

I will bang on it today but I am sure that will work. What works now is to used my remote starter cables with button to engage the solenoid rapidly until it makes contact. You can't do the with the key because you have to turn it back every time.

It's a tough problem to diagnose because it usually starts perfectly. So I just have to wait or start and stop it a dozen times or more before it acts up.

The next time it will not start with the key I am going to try and measure voltage and see what that is. It doesn't make sense though because it usually starts fine with the key.

It's completely random as far as I can tell.

It doesn't take much electricity from the battery to get the click. I takes a lot of electricity to run the starter motor. Since you have gotten the same symptoms from two different starters and two different solenoids, I think you should go over the electrical connections again. Start with the battery terminals and the cable connections. You can clean them with a wire brush or with a pocket knife. There is a commonly used battery terminal wire brush tool that you can get at any auto parts store to do that. They generally sell for less than $10; one end cleans the battery terminals and the other cleans the cable connection to the battery. If you use a pocket knife, don't scrape too vigorously, because you take off too much of the metal.

I worked in an my dad's electrical repair shop for six years a long time ago. We got your type of problem on what are now old American cars with some regularity. The problem resulted from a bad solenoid, a bad battery or a discharged one, or from poor electrical connections. The electrical connection problem was most usually corrosion at the battery connections. It can look fairly good and still have corrosion. Also check the cable connection at the solenoid. Make sure it doesn't have corrosion and that it is fairly tight.

You may have the same problem if your buy a new starter since you've had it with the two different starters and solenoids you have had on the car.

I have done all of that. All connections are super clean and tight. The switch or plate inside the solenoid just randomly does not make a connection. This morning I tried to start the car after it sat all night and it started up perfectly. Drove it till it was fully warmed up, drove it on some rough spots to cause vibration, shut it off and it restarted perfectly. Shut it on and off several times and it started without fail every time.

For all I know it will never happen again! This problem is really getting on my nerves!

I'm trying to think that of any different tests to nail down the cause but it seems like swapping starters may be the only one left at this point.

Where did you find new. I saw remaned Bosch at ********az. The car is actually a friend and he pays me. I already thought I had it fixed twice. Once after I replace the neutral safety switch and then after I put in this used starter. Both times it worked until he drove it for a few days.

That job was a bear. First time after owning four 617s. I've swapped and engine and a transmission but never had to mess with the starter.

Here is what the old starter solenoid contacts looked like. Do not know if this is normal or not. The plastic broke on the way out so I could get a look at them. It looks like copper transferred from the lug to the plate over time.

It looks like they are all rebuilt but still high quality.

I did a little more work. Added a ground directly to the starter and tested voltage. Voltage to trigger wire with key was 9.2. Directly from battery with remote start cables 10.1. Both work and both fail to work. I also tried hitting it while holding down remote start trigger and it had no effect. I must have pressed the remote start button a dozen times with just a clunk. Left for two minutes to get a hammer and before I tried the hammer I hit the remote start button and it cranked over perfectly normal. Absolutely nothing changed in those two minutes. WTF! I think I am going to have to get a new starter because I don't know what is left?

I've seen similar before though I can't say that it's normal or abnormal. As others have stated, that's a LOT of amps being transferred right there. I'd for sure replace it - no reason not to other than cost.

Dan

You already asked yourself: What is the chance that 2 starters behaved exactly the same way?. What's your answer?

I'll ask this: What is the chance a third starter will behave the same way?

I'd suggest taking MXFrank's offer and borrow the starter tester. If it works as advertised, will take the guesswork out of your measurements.

I'll take a voltage and current readings of my starter solenoid tomorrow so we can compare.

How did you get it apart? The solenoid is a sealed unit and cannot be taken apart easily.

What do you mean "plastic broke on the way out" If the plastic was already cracked, It was likely caused by over torque of the solenoid nuts, as I mentioned previously..

Somehow I missed your post. I am almost certain the problem is in the solenoid. If I jump the lugs on the solenoid the starter spins no problem. I also hooked voltmeter hooked up for continuity on the lugs and when I have the clunk symptom there is no connection between them.

That's a weird one but such things CAN and do happen. Best of luck - I'm holding on for the ultimate answer.

Dan

Somehow missed your post yesterday. I really appreciate the offer. I found I great deal on the this and got it shipped new for $10.80! Otherwise I would have borrowed it but this is cheaper than shipping yours twice. I do not know if it will tell me anything new because I have done a lot of test with a voltmeter but... it seems handy to have.

When I was removing it the plastic broke because I was not careful with it. I thought I could get it out without taking the steering linkage loose.

I leant the hard way. When buying a German car starter as a rebuilt. If the solenoid does not appear new pass it by. I had various troubles with the rebuilts if the solenoid appeared old but just cleaned up.


It may have been a case of just bad luck on my part. . On the other hand it is an expensive part for a rebuilder to put in new.


I think the problem might be the solenoid may act very well on a test with twelve volts applied. The problem being the activation of the solenoid in the real world is getting much less than twelve volts.


Personally I want no cheaply reconditioned alternator or starter out of Mexico. Any rebuilder has a choice of very cheap parts or fairly expensive replacement parts.


The cheap replacement parts are so bad reputable rebuilders do not use them. I have used some of the cheap parts myself and they are seriously hit and miss at best.


There are one or two rebuilders in California that have a great reputation and are very reasonable in price. For most members even including the shipping you may land up with a quality rebuilt. Cheaper than the junk rebuilts some chain operations sell.

Did you pry it out? The starter should come out without having to remove any suspension components. It's a bit tricky but the procedure is well documented in what you need to do.

I measured the solenoid voltage and current while it was cranking: 9.5V @ 7 amps.

This is how it was measured:

Voltage at battery terminal = 12.7 V

Connected the small screw on the terminal block to + lead of digital volt meter, negative lead of meter to battery - terminal.

With another digital meter set on 20 amp scale, use meter leads to jumper the small screw on terminal block to the big screw. It starts cranking and the voltage and current values are displayed on the meters. Engine did not start (just keeps cranking as long as the terminals are jumped) since there was no glow and no fuel because the key was in the off position, shutting off fuel to the IP.

I did not measure with the starter not cranking. That's a lot more work, requiring disconnecting the big cable at the starter.

You cannot use an ohm meter to measure ohms on the starter lugs with voltages on it, you will get an incorrect reading.

123 look very closely and test that wire you have in the picture for continuity that wire is where my intermittent starting problem was. The wire looked good but it was not making a good solid connection all the time when I would tap on the starter it would start fooling me to believe problem was in starter. I think I finally found the problem when it did not start to trace each wire to see if it was delivering voltage or not. I have since have no problem starting ounce I replaced the end connection of that small wire. These cars are 32 yrs. old and the wires become very brittle and can break inside which you cannot see on the outside. Hope you figureit out.

Replaced that wire completly. Unfortunately did not make a difference. It always showed voltage before and after but I replaced it just for heck of it. A waste of time I guess.

I really appreciate everyone's help so far. Even though I do not know excactly what is going on I have elimated what seems like every possibility outside of the starter solenoid. I am probably going to order a new Bosch unit and hope for the best.

Find the closest Agricultural Town near you... find their Alternator/Starter repair shop.
These kinds of places fix starters for tractors and stuff you can not get new or rebuilt ones for....and you would not want to if they can be rebuilt anyway....
I did this when I was having Exactly the symptoms you describe....
They took it apart while I was standing there.... it turned out to be the three small screws in the end which hold the ' cage ' which hold the brushes....
It took a big vise and a lot of muscle to open it up... probably the first time since new... it was about 25 years old at that time...
So at some point you might need to just take it off and take it to a professional...