Starter Solenoid Doesn't Like Weak Battery

[Carimbo]

Interstate MTP-24 800cca battery past its prime, getting to be a gamble to see if it will start the engine, waiting for its replacement to arrive.

Interesting observation: Smoke emanating from the starter solenoid during starting attempts. Starter and solenoid not hot nor even warm to the touch. The plastic end (where the electric terminals come out of) can rotate ~5 deg. in the "can." Don't think it is supposed to, but does that indicate problems?

10 sec. cranking attempts or less.

Huge (2/0?) battery cables.

[asavage]

I've put MTP-27 (750 CCA) in both my Maximas. I only buy Interstate batteries. They're $105 each!

A failing MTP? Is it very old? I've seen them run for years beyond life expectancy.

Smoke from the solenoid is probably not normal. Voltage drop across the solenoid is high, I'll bet. Can you clip-lead a voltmeter across the solenoid's big terminals and observe while cranking? Under a half volt would be good.

Meanwhile, if you need a starter, I've got a spare from the JY:


It's available for loan, I can ship it too.

[TheDieseliminator]

I've put MTP-27 (750 CCA) in both my Maximas. I only buy Interstate batteries. They're $105 each!

Speaking of batteries I wanted to ask about the Interstate. I'm going to need a battery pretty soon for my Maxima and would like to consider a high quality unit with cranking power sufficient for the diesel. Is the MTP-27 model Interstate battery the one listed as fitting the 81-83 Maxima diesel or is it just one that you found fit into the battery space well and the cables hooked up much like the factory had? I'd like to buy one given it fits our application, which I'm sure it does. At 750 CCA is that around 900-1,000 regular cranking amps? Anymore advice would help. Thanks.

Salvy

[asavage]

I think the one I picked was one I picked off our rack, not by application. It fits well, but according to Carimbo is rated 50 CCA less than the smaller MTP-24 that he's using.

[Carimbo]

And the MTP-24 is a few $$$ less. Mine was a 1996 or 7 MY, IIRC! Probably would be going strong(er) today, if we would not have tried so hard jump-starting my friends Aerostar that we soon found out had the pos cable shorting out where it chafed thru passing inside the stay that was supposed to hold it clear of the power steering pump.

[Carimbo]

Can you clip-lead a voltmeter across the solenoid's big terminals and observe while cranking? Under a half volt would be good.

Thanks for the tip Al. Currently working on making a set of test leads for this test. I have a good assortment of test leads but the clips on all of them either do not open wide enough or allow my hand to open them sufficiently in that contorted position to clamp them onto the terminals. Tried and accidentally bumped the starter.

Radioshack had some alligator clips that open wide enough, and have an upward-angled thumb lever that looks like it should do the trick.

[TheDieseliminator]

Well, I bought an MTP-27 battery yesterday at a local Interstate battery dealer, get this about 2 minutes away from where I work. It was basically so close you could walk there. Now the engine fires over cherry and I've gotten rid of the old Everstart (Wal-Mart) brand that had been in the car the past three years. It was funny the guy that installed the new Interstate for me said something like this, "Made in Mexico, the story of their lives" when he was taking the old Everstart unit out (has a black sticker that says Made in Mexico on it). I chuckled in my head and thought it was funny. He also mentioned that the MTP-24, although it has more CCA (800) has a lower reserve, while the MTP-27 has a higher reserve that he did mention he recommended for a diesel. I don't know every single piece of knowledge about batteries, but I trusted him. Plus he said both were the same price which I didn't expect before I went to the place. Good deal at $80 too and I had to give him the old battery as a core.

Salvy

[HowlerMonkey]

Check the negative battery cable where it has a tab to bolt to the battery tray.

Liquid gets between the sheathing and the bare copper cable and starts to corrode it to the point that it shows good voltage when testing and then gives up under load.

The bulging of the cable is a dead giveaway.

[Carimbo]

Not sure it has the original cables, but you have a good point. If it is not the original cable it probably lacks the tab, but I can inspect it for any bulges. What are some other methods to check the soundness of the cables?

[asavage]

Voltage drop analysis.

Put a voltmeter's probes on the Neg. post (not the terminal, but hold it on the post) and an engine ground point -- like a rocker cover bolt or similar. While holding those probes in place, have someone operate the starter. In an ideal world, you would see no voltage indicated. In the real world, that much current through that many feet of cable and the various connections will have some resistance, and that resistance will be revealed by the amount of voltage "dropped" as indicated on the voltmeter.

I like 0.2v or less; in real world situations, you sometimes have to settle for 0.5v drop, or start replacing connectors or cables.

Note that by putting one voltmeter probe on the battery's Neg post, you are checking for resistance at the battery terminal as well as the cable and downline connections.

If excessive voltage was indicated, move one or the other voltmeter probe measuring point toward the other probe. When the measurement shows much less during testing, you just passed the bad connector (or wire segment).

Use the same method to find a bad connector or cable on the starter cable. Or any wire that carries significant current.

[For this, I paid $3000 in 1980. I did learn a couple other neat tricks too though.]

[Carimbo]

DVOM clipped to both large terminals on starter gave 0.7 - 0.9 VDC while cranking. After starter stopped working this read 0 VDC while attempting to crank (see below).

DVOM clipped to neg. battery post and washer bottle mount showed 0.15 VDC while cranking.

DVOM clipped to neg. battery post and engine hoist bracket showed 0.6 VDC while cranking.

Then it got weird. Scratched the clip on the engine hoist bracket to make sure it had a good connection, went to crank the starter, and::::::::::::: no cranking anymore, just a click from the starter solenoid.

Next I tested:
DVOM clipped to pos. supply post on starter and pos. battery terminal gave 0 VDC while cranking (actually not cranking, but starter solenoid energized [hotwired]), same 0 VDC reading for starter motor lead post on starter.

Strange results, I suspect starter solenoid internal damage.

Al, I will take you up on your offer to loan me the starter, thanks. $15 MO (my shipping guess) is in the mail to you.

[philip]

DVOM clipped to ...SNIP ... Strange results, I suspect starter solenoid internal damage.

In addition to Al's $3,000 lesson, I was instructed (this was a Delco C-4 class in 1980) that for this test ... to use a conventional analog meter, not a "high impedance digital VOM". Over the years, this requirement has proven true.

Delco rule was: 0.2 volt drop across a connection, 0.5 volt drop across a switch contact.

[asavage]

. . . same 0 VDC reading for starter motor lead post on starter.

Key in "Start" position (or equivalent via hotwire to little spade terminal on starter):

VM neg to ground, pos to starter's battery terminal = battery voltage or close.

VM neg to ground, pos to starter's motor terminal = no more than 0.5v lower than battery voltage.

Be sure and include a shipping address for the starter. It's a "spare" and I have no immediate need for it, return it when convenient (within the next couple of seasons, anyway ).

[DVOMs are much too sensitive for troubleshooting use in many cases, as Philip's Delco class said. It'll esp. measure transients much too easily. In the Good Ol' Days, you had to have real current available to make the needle move, the high impedance of DVMs make them susceptible to odd readings.]

[asavage]

Some solenoid info:

Nissan's part No. for the Apr-81-on LD28 solenoid is 23343-W1700 and Google shows many hits, most Taiwan and China sources.

Nismoparts.com turns that number into B3343-07G00, which doesn't seem to get anywhere, but they list it as available (for what that's worth) for $61 + $10.

NAPA (Echlin) lists a solenoid, ECH ST306, $72

[asavage]

Al, I will take you up on your offer to loan me the starter . . .

My spare starter's got a bad solenoid . That's the one from the Silver '82 in the Lynnwood JY.

I'll get my other starter out of storage tonight, and test it in the AM. No delivery tomorrow -- it's a Fed holiday -- so no delay.