TR4/4A TR4 Starter and Solenoid Issue

[KVH]

I could use some help.

When I turn the key I hear that dreaded "click" (a single click), and nothing more. When that has happened in the past, I have always suspected the battery first.

However, in this case my battery was recently charged, shows 12.7 volts at rest, and a specific gravity test shows all cells alive and strong.

In addition, the car had been running great--until today when I had to push the car to start it. I get nothing but a click when I turn the key.

This evening, I got out and tried pushing the solenoid button in, and the result there was a bit startling.

Rather than a click this time, I got smoke, apparently from the solenoid, right where the wires connect, but the wires didn't seem all that warm. The solenoid housing was warm.

I tried pushing the manual solenoid starter button "in" again, and it stuck in the "in" position, but then finally popped back out.

My starter was rebuilt 3 years ago, and I have no reason to suspect that, but I just don't know.

So here's the question. Is it my solenoid or my starter. I doubt it was my battery. I also doubt it was my battery cables; those look clean.

Do I buy a new solenoid? Or, should I pull the starter and have it tested first?

The "click" sounded more like a starter click, but I dare not reconnect the solenoid after seeing smoke. I even wonder
if I may have blown anything by pushing in that solenoid button. I guess I'll see.

Thanks for the help.

 

[Don Elliott]

My TR3A has a separate starter solenoid on the firewall. If yours is similar, disconnect the two heavy wires from the solenoid, joint them together with one of the cables from your set of battery starter cables and see if the starter turns over briskly. If it does, you need a new solenoid. Don't leave the clip from your starter cable connected too long or your starter will keep on turning.

 

[Andrew Mace]

Most of what you describe sounds like a classic case of dirty and/or corroded terminals -- those on either end of each battery cable (or possibly even the terminal clamps themselves where they attach to the cable), on the solenoid, on the starter and perhaps on the main ground cable from the engine. It's also possible that the solenoid has seen its last start, but it could have stuck temporarily due to getting a bit warm.

Possibly even easier than Don's suggestion is to get a medium sized screwdriver with a good insulated handle and use it to quickly bridge the two big terminals on the solenoid to see if the starter will then work.

Oh, and I seem to remember that the solenoids can be disassembled somewhat to clean them up...either that, or you might be able to use something like a WD-40 to clean and lubricate them. Not too much that can go wrong there.

 

[KVH]

I forgot to mention that the negative pole of my battery was also quite warm.

Should that make me think that my battery cable at that end actually was not clean and connecting properly, and that my problem is more simple than I thought? (it wouldn't be the first time I over-reacted to some symptom)

I already removed the solenoid and bench tested it. It seems fine.

Maybe I just need to clean the cables and put it all back together--and try again.

 

[KVH]

Andrew, yes, I'm suspecting what you say is the case. I'm going to clean everything, and put it all back together. I'm going to feel just a little silly if it fires right up.

 

[Geo Hahn]

One connection that you will not want to overlook is where the big cable connects to the starter. That spot (on my car anyway) can get hot and oily, not the best conditions for electrics. I have had it become a problem resulting in non-start, heat and smoke.

 

[Andrew Mace]

I'm going to feel just a little silly if it fires right up.

...just like each and every one of us has felt, at one time or another. Consider it a rite of passage!

 

[Don Elliott]

Maybe you have lost some of the Lucas smoke from the insides of your wires and/or cables. Check it and see if you might need to add some smoke to replace what you have lost.

 

[rggav]

I had the same problem with my MGB. My starter on the 65 MGB has two nuts on the post that connects the cable to the starter from the solenoid. I had tightened these nuts because they were loose. After I did this I had the same problem that you have and before the starter was working fine. I discovered that there is a fiber washer between the starter and the first nut that insulates the starter connection lead from the case of the starter. When I tightened the nut I broke this 45 year old fiber washer. I replaced the washer with two fiberglass ones I bought and presto I was back in business. My leads were also smoking because they were shorted out to the starter case.

 

[tdskip]

I forgot to mention that the negative pole of my battery was also quite warm.

Guys - what do we think the cause for this is? Is it the internals of the cables corroding?

 

[Don Elliott]

Soundslike dirty connections to me. Remove the battery cables from the battery posts. Chean the insides where the cables get tightened to the posts. Clean the outside of both battery posts and reattach the cables tightly.

 

[TR3driver]

I forgot to mention that the negative pole of my battery was also quite warm.

Guys - what do we think the cause for this is? Is it the internals of the cables corroding?

It's possible, but more likely IMO it's poor contact between the clamp & post.

The currents involved here are huge (stock starter can draw over 500 amps), so it's easy to have a marginal connection that works fine except when trying to start the engine.

But I have even seen a battery break internally and get hot at the posts, so anything is possible.

 

[tdskip]

Sorry if I wasn't clear, but I was asking if the cable to the battery might have internal corrosion that could be adding resistance and thus heat.

 

[rggav]

You could try these voltmeter tests on the cables :

MG Car Repair voltage tests

 

[TR3driver]

Sorry if I wasn't clear, but I was asking if the cable to the battery might have internal corrosion that could be adding resistance and thus heat.

Ok, so just to be clear, I was saying that it is possible. However, in my experience, poor contact between the clamp and post is much more common, even if it looks clean and tight. So my first step would be to remove the clamp, clean both surfaces until they are bright and shiny (most FLAPS will have a brush for this for a couple of bucks), and make sure that the pinch bolt can actually pinch the post firmly. Add a smear of anti-corrosion grease (Vaseline), reassemble, and re-test. If it still gets hot, the cable might be at fault.

Or as someone else said, the starter might be shorted. I smoked the entire cable from battery to solenoid once, because one of the starter brush leads had gotten tangled in the commutator. It was cranking the engine, but really slowly, and apparently drawing several times as much current as normal.

 

[KVH]

Update TR4 Starter and Solenoid Issue

OK, I'm really at a loss.

I cleaned the cables, and checked everything. I tried to start the car.

WOW!

I got a big spark where the flat "eye ring" of the negative cable bolts into the body firewall of the car, right near the windshield. The cable connector at that location, on the firewall, actually exploded off the bolt. In other words, the ring connector at the end of the cable just exploded in half.

Calming myself down a bit (after checking whether I fried my entire wiring harness, I might conclude that the problem from the very beginning--when my car would not start--was the connection at the firewall.

Does this make any sense?

Do I dare put new cable on the negative terminal, bolt it to the body and fire it up?

I guess I should try it, since the only rational explanation appears to be a bad cable.

More info: Before all this happened two days ago, when my car first would not start, I had installed and removed my battery twice, so maybe it did weaken the ring connector on the cable and it was just ready to fall apart.

Thoughts? Thanks in advance.

 

[Andrew Mace]

Re: Update TR4 Starter and Solenoid Issue

I got a big spark where the flat "eye ring" of the negative cable bolts into the body firewall of the car, right near the windshield....Calming myself down a bit (after checking whether I fried my entire wiring harness, I might conclude that the problem from the very beginning--when my car would not start--was the connection at the firewall.

Does this make any sense?

It does to me...that the cable, or at least that end of it, might have been bad all along.

Do I dare put new cable on the negative terminal, bolt it to the body and fire it up?

Sure, so long as you've determined that there is no other damage as a result of your impromptu light show! :wink:

 

[TR3driver]

Re: Update TR4 Starter and Solenoid Issue

I might conclude that the problem from the very beginning--when my car would not start--was the connection at the firewall.

Does this make any sense?

Makes sense to me, too. The heat at the battery post might have traveled the length of the cable, if you only felt at the post.

Not likely to be any hidden damage, so I'd just chase the threads, clean the post, and install the new cable.

I would suggest buying a new "external star" type lockwasher and putting it between the cable and the body. The points of the star will cut through the paint and help ensure a good contact at this point. Otherwise, you need to strip the paint off and expose bare metal to get a good connection.

 

[Geo Hahn]

Re: Update TR4 Starter and Solenoid Issue

...WOW! I got a big spark where the flat "eye ring" of the negative cable bolts into the body firewall of the car, right near the windshield. The cable connector at that location, on the firewall, actually exploded off the bolt...

This is why you should invite me over when you're doing this sort of stuff -- I really enjoy watching fireworks.

I scrape with an Xacto knife on the surface where the cable meets the firewall, not only removes any paint but presents a nice shiny clean contact. The star washer along with this should be good insurance.

Haven't looked real recently but last time I got a ground cable they were still carrying the braided type at the FLAPS, I think that looks more correct if such a thing matters:

 

[rggav]

I would also install a battery disconnect switch so you don't have to mess with the battery connections the next time you work on the car. Just use the disconnect and nothing gets pulled or damaged.