Watershed electrical moment?

[Jim Lee]

Ok forum folks, I think I might have stumbled across, for the second or third time, a watershed moment in my TR3 troubleshooting career. I have been babbling on about starting problems in various disguises for a few years but I think that I have finally got a solid lead here.

Symptom:
With battery fully charged and having the TR running beautifully the day before I go out and turn the ignition key and click..then all ignition off. Dead as a doornail. I poke around aimlessly for a few minutes tightening up battery cables and checking other stuff and try starting again. Same sequence. A strong click-clicking of my electric fuel pump then either a very weak few turns of the engine and then click. Lights out all over. If I am very lucky the engine will start up on the first few turns. If I am not I usually assume that the battery is bad. This time I know the battery is good and is well charged.

Now, I am hoping against hope, mostly because the weather is so unseasonably nice that I NEED to be riding around in my TR, that you all can give me a direction to go on my hunt based on this observation. When I turn the engine over from the starter/soleniod in the engine bay, with the ignition switch off, it turns over as I would expect a fully charged battery to turn over a competent starter. If I then turn the ignition switch on, then push the same starter in the engine bay, it barely turns. I might get a couple of turns or three at most. Unless the engine has been run recently then not enough to start.

So the question I want to pose is why is there such a difference when I add in the ignition system which of course has to be present and accounted for if the engine is to start?
I thought that the two electrical systems, though related by the same battery power source, were separate from each other. It seems to me that there is something about turning on the ignition that is draining so much of the battery power that there is barely enough left over to turn the starter at a sufficient strength to start the engine. Any ideas on either where that load could be or how I could find it?

Lastly, if I am lucky enough to get the car started with the anemic few turns of the starter that the ignition on state allows me...then the car runs like a perfectly. Once it has warmed up even just a little I am able to restart it because it is then so easy to start. For example if I can start it first thing in the day then I am good for the rest of the day. But the next day I have the same problem starting.

I have done a bunch of tests with the two most recent being testing the continuity of the positive and negative cables. I am going to replace both of them just for good luck even though they tested fine. I am also going to clean up the place where the negative cable grounds to the firewall. I don't have any high hope of this being the issue though as I believe that the healthy turning of the starter without the ignition on shows that the battery and its cables are doing there thing competently.

Thanks very much,
Jim Lee

 

[Don Elliott]

Unless you or some PO has changed over to negative ground, the positive post on the battery should be connected with the braided grounding strap to a 7/16 28 UNF bolt on the firewall up above the battery. See photo of mine in my 1958 TR3A (TS 27489 LO).

Maybe you have too much paint where that bolt is screwed in.

Maybe your battery is wrong way round.

 

[Jim Lee]

I am negative ground. The negative grounding strap must have been replaced with a 'normal' black battery ground wire before my custodianship. I am going to replace both those wires and thoroughly clean the place on the firewall where the negative ground attaches.

Thanks,
Jim Lee

 

[AltaKnight]

If the battery were under such a high ignition system load that there is nothing left for the starter there should be accompanying signs of smoke/sparks and melting battery cables.
It's much more likely that the real problem is bad electrical connections causing high resistance, either on the ground side or in the ignition switch end of the business.

 

[TR3driver]

How long can you crank the engine with the ignition off?

How do you know the battery is good? It's been a few years back, but I once had somewhat similar symptoms with a nearly new battery. After much frustration, including several professionals pronouncing the battery "good", I finally realized that there was a broken conductor <span style="font-style: italic">inside the battery case</span>. Installing a different battery solved the problem forever.

Bad connections elsewhere can also cause strange symptoms.

BTW, using a large star-type lockwasher between the ground cable and the body will usually eliminate the need to scrape off the paint. The points of the star penetrate the paint.

 

[71MKIV]

Does the engine spin normally with the ignition off. If it does, try this.

take the cable off the battery side of the solenoid and try touching it to the starter side with the ignition on, trans in nuetral and brake on, with the wheels chocked, don't run over yourself.

it will spark, so be ready, but If the engine spins normally your solenoid has issues. It's possible that the solenoid is going flaky on you. The button on tip might make good enough connection while the elecromagnet doesn't.

 

[Jim Lee]

I finally got to the point where I turn the ignition on, hit the starter and all I hear at the solenoid is a click. I would love to try the other solenoid that I have but I do not have the Whitworth nuts.

Tried this, assuming by 'battery side' you mean positive in a negative ground system:

"take the cable off the battery side of the solenoid and try touching it to the starter side with the ignition on, trans in nuetral and brake on, with the wheels chocked, don't run over yourself.

it will spark, so be ready, but If the engine spins normally your solenoid has issues. It's possible that the solenoid is going flaky on you. The button on tip might make good enough connection while the elecromagnet doesn't."

With the ignition turned on, jumped the positive cable to the bottom pole of the solenoid instead of the top and it sparked like the Fourth of July but did not do anything else except blacken that pole on the solenoid. Not a peep from the starter or anywhere else. I had thought it was going to turn the starter but it did nothing. Would I not be doing the same test but more directly by attaching a starter cable to the positive side of the battery with the other side going directly to the starter? So that I would be bypassing the solenoid all together? I am curious though as to how that would differ from the test that I did above. I am also surprised that I did not get any response at all from my starter in the above described test.

I have ordered still another solenoid that I should get next week but I am still skeptical about my problem being simply a(nother) bad solenoid.

Thanks,
Jim Lee

 

[TimK1955tr2]

I would double check that the battery is functioning 100% under all conditions - have it load tested or swap with a known good one.

Batteries have a relatively high failure/defect rate - internal issues as mentioned above.

 

[71MKIV]

It's beginning to sound to me like you've a wonky starter.

Puttin the 12 volts right into the starter like that should have spun it over without any difficulty because you've eliminated all connections in the middle.

How old is the starter again?

Also closely check the ground strap for the engine to the frame. The juice from the battery has to get back there somehow.

 

[Jim Lee]

The starter is original but has been rebuilt by myself (not personally) at least once, so not that many miles ago. It could well be the starter but I am still really stumped by why it would turn very strongly without the ignition on and then be so weak with the ignition on. I have cleaned up every relevant ground wire that I can think of...like the fuel pump which as far as I know is the only load other than the starter and ignition when starting.

Right now I am planning to see if the new starter/solenoid changes the equation. Of course the other thing that is puzzling is why I am unsuccessful trying to jump the starter by jumping over the solenoid. If I get really brave I am going to try using a battery jump cable to go directly from the battery to the starter.

The starter is grounded through/to the engine right?

Thanks very much,
Jim Lee

 

[TFB]

If the starter cranks fine with solenoid push button,I think you can rule out starter ,and all the high current wiring.I would suspect that something on the switch circuit is adding load,or you have bad solenoid,or no 12v from switch,or bad solenoid ground.Did you try to connect battery cable ,or wire, to small pole + on solenoid,with switch off.If this doesnt work,and cranks with button,I would bet on bad solenoid,or solenoid ground(I think to bulkhead with mounting bolt.)
Hope you figure it out
Tom

 

[RJS]

Jim,

I've read this whole thread and for me, at least, these two statements from your original post are key to whatever your issues is:

"When I turn the engine over from the starter/soleniod in the engine bay, with the ignition switch off, it turns over as I would expect a fully charged battery to turn over a competent starter. If I then turn the ignition switch on, then push the same starter in the engine bay, it barely turns. I might get a couple of turns or three at most."
"I thought that the two electrical systems, though related by the same battery power source, were separate from each other. It seems to me that there is something about turning on the ignition that is draining so much of the battery power that there is barely enough left over to turn the starter at a sufficient strength to start the engine."

Given these facts, I would not suspect the battery or starter. I would suspect it is something else directly related to the ignition switch being "on" and would look there. I'd start with the ignition switch, then the solenoid.

Sounds like you've experienced bad solenoids in the past, as I have. The quality of the new solenoids today from the big three are suspect at best (all of $16). I've had issues with the contacts sticking and the starter continuing to run. Usually, a rap on the solenoid with a hammer is enough to remedy.

I've done some research and "next time" I'll probably go with a much higher quality option from NAPA (these are direct replacement listings for a '66 TR4A):
Echlin PN: ECH ST 236 = $49
Altrom PN: ATM 1437001 = $72

I have also read here on BCF these solenoids for a '72 Ford Maverick will work
Echlin PN: ECH ST 81 = $24
Echlin PN: MPEST81SB = $12

Hope this helps and wish you luck,

Bob

 

[71MKIV]

um, just thought of something,

What's the timing set at? If it spins normally with the ignition off and way slow, jerky perhaps? with the ignition on, is the starter just weak?

if the timing is way advanced the starter has to push through the expanding fuel charge.

 

[Jim Lee]

Steve:
"What's the timing set at?"
I am pretty confident about the timing. When the car does start, and it will if I get lucky and it 'catches' on the first couple of turns, it runs great.

Bob:
"I'd start with the ignition switch, then the solenoid."
What can I do with the ignition switch other than test it for voltage?
As far as the way it is working now it seems to be doing its thing exactly as it has always. Turn the key and the red oil light comes on and my fuel pump starts ticking away. Sometimes after I have tried to start it 3 or 4 times I will turn it and it will just click off. If I turn the key after that I get nothing. If I wait a few minutes it will act normally again. Does that not suggest that something is getting over heated, then cooling down when it works again? I was thinking that the fuel pump might be drawing more juice than it should but it is working absolutely normal and I thoroughly cleaned up its ground. All the grounds that I am aware of, engine, battery another one that I attached to the generator, I have checked and double checked. I have to look at my schematic but is there anything between the switch and the push button and the solenoid? When you turn the key and it stops working I believe I hear a click and it is just like a fuse blew. Both my fuses are fine.

I have replaced the solenoid before thinking that was the problem but I am getting the feeling that there is something else electrical going on that might have been lingering in the background though allowing me to start and drive the car after charging the battery. I do not drive it as often as I should. I should be getting the new solenoid early this week. I think I am going to see if I can track down some Whitworth nuts so that I can also have the original one to use. I have a feeling that that is working fine and I replaced it earlier without getting to the root of the problem.

Tom:
"Did you try to connect battery cable ,or wire, to small pole + on solenoid,with switch off."

Are you talking about connecting the battery to the lower pole on the solenoid instead of the normal one on top? If so, when I tried that, with the switch off, I only managed to initiate a giant spark and some serious heat at that lower pole. It was like I was spot welding on the pole. The starter did not move and I did it maybe twice and then decided it was not a safe thing to do. I am debating whether I should try going from the battery to the starter directly with jumper cables but I am pretty confident that the starter is ok as it turns strongly with the ignition off. I will test that again tomorrow.

Thanks,
Jim Lee

 

[Jim Lee]

I am looking at the schematic and wondering about the starter push button. Is there a way to test that individually? Separate from the car. It does its thing but I see that the wire from that goes directly to the solenoid. I am also going to look at the wire labeled '33' and brown in the schematic which goes from the A1 fuse to the solenoid. And from the A1 fuse to the ammeter and then to the 'A' terminal, labeled wire '37' brown/white. The only kind of test I can think to do though is continuity from one terminal to the next.

Thanks,
Jim Lee

 

[TR3driver]

I am looking at the schematic and wondering about the starter push button. Is there a way to test that individually? Separate from the car.

Just basic continuity.

The thing is, a healthy car battery can supply a huge amount of current for a short time, literally hundreds of amps. If anything else in the car were drawing that kind of current, the wires would quickly smoke.

So, either the battery itself is defective (possibly a broken internal conductor, damaged plates, worn out or simply discharged), or you are looking at an intermittent bad connection (meaning high resistance). Your initial description above sounded to me exactly like the problems I used to see with battery cables that were not making good, clean contact with the battery posts. I have even started cars by using my pocket knife to peel off a bit of lead and lay it so it shorts between the top of the post and the clamp.

Something else to consider, most continuity checkers will show continuity for a resistance as high as 10 ohms (or more). But 10 ohms won't pass even enough current to operate the solenoid, let alone the starter. Even 1 ohm (which is tough to read with an ordinary ohmmeter/DMM) will cause problems. You'll get a much clearer picture of connection quality by measuring voltage drop under load.

Get a voltmeter (even a cheap DMM from Harbor Freight will do), and check the voltage right at the battery posts with the key on. If the voltage is less than 12.5 (maybe a little less if the weather is cold), the battery isn't doing it's job. Now turn the headlights on for 5 minutes or so, and check the voltage again. If it has dropped appreciably, again the battery is bad or not charged.

 

[TR3driver]

I am debating whether I should try going from the battery to the starter directly with jumper cables

Bad idea, IMO. The small contact area between the jaws of the cables and the post on the starter can easily generate enough resistance to cause a false indication, or even enough heat to melt the post. Similar to what you saw trying to connect to the lower solenoid post.

 

[KVH]

Experience from my TR acting erratically on ignition or attempted start:

It was the battery all along in one case.

In another it was a very "hidden" unsuspecting problem with my negative ground at the fire wall. This caused seriously confusing issues for several days, as the ground was first OK, then bad, and back and forth until the current literally blew and sparked the eye-ring right off the bolt.

If it were me, I'd try a new battery after triple cheching the cables and firewall or other ground.

Big problems are often little things.

thx

 

[Jim Lee]

Got new solenoid. Same exact deal. Turn ignition on...click..everything off. Wait a few minutes and go through the same cycle. Only thing different this time was that when I pushed the solenoids starter button I also got absolutely nothing as opposed to a healthy turning. All the cables, except one, in the starting system are new. The negative cable from the battery is well grounded. The battery measure 12.5 volts before I started. This battery has the date 7/08 which makes it closer to 3 than 2 years old. Since I do not use the car on a regular basis I am still holding out hope that this problem is a battery problem. Notwithstanding my boys up at AdvanceAuto telling me the battery was fine.

I am charging up a battery from another car to see if I see anything different.
I will keep you all posted on tomorrows 'other battery' event. I know it sounds like a ground problem but the engine ground is firmly attached and the battery ground wire is new and the place on the firewall where it attaches is really clean.

Thanks very much,
Jim Lee

 

[mrv8q]

Good luck and keep posting....