OT (Mostly) - Remember the Car Talk Puzzlers?

[A.K. Boomer]

[QUOTE=lynnl;n2000692]

He did. ...see last sentence of 3rd paragraph.

Here's the answer they give:

Well, the truth is there was probably nothing wrong with the original battery. What was wrong was that the alternator was in fact faulty. The first alternator the mechanic replaced was indeed the right alternator, but it had the wrong size pulley. The pulley was too large in diameter and wasn't turning fast enough.
[End Quote]

Just plain stupid --- that's why i did not initially respond to the OP because I knew the answer defied "normal logic"

first off --- the vehicle never should have left the shop after the initial alternator replacement because a proper replacement INCLUDES taking a voltage output test AT IDLE WITH THE HEADLIGHTS ON and posting the results on the work order!!! so how can you possibly diagnose a "puzzle" like this when it's written by a couple of hillbillie's who really don't know proper repair procedure in the first place?

secondly --- they say the battery goes dead after a couple weeks? as in nothing? was the car just parked or being driven ? just parked and with a new battery the vehicle can do just fine sitting for a couple weeks --- and using the vehicle daily would mean it could quit day one if the vehicle was being driven in city traffic (lots of idling) at night with the headlights on,,, so why a timed "two week interval" again - senseless hillbillies writing up the mix....

FWIW ------- Here's the best possible answer to what was so poorly put together, the vehicle initially had charging problems - but they don't go into intervals initially, just battery being dead, so new battery - battery still goes dead - could still be a faulty replacement battery --- could also be the fault lies in alternator - but no testing of the charge system after means your shooting in the dark, still - initial problem could have been alternator brushes - regulator or diodes --- whatever...

But --- second alternator does not help the situation, and now their talking "timed intervals" there is one thing *( actually many related) that can create this type of situation and that's that the second *(most likely remanufactured) alternator had Diode failure in fact perhaps the reason it got replaced from another vehicle to begin with and they did not catch it in the rebuild because the diodes acted like diodes...

But alternator diodes can act normal 99% of the time --- and then all the sudden backfeed and discharge the battery when the vehicle is parked,,, sometimes they can do it with surprisingly predictable intervals - say when a battery loses a certain surface charge (after a couple weeks of parking the car) and then the voltage hits the "sweet spot" to trigger the diodes malfunction ,,, then it's full blown discharge of the battery in fact so much so that the parked vehicles alternator will go from room temperature to actually heating up very hot, the power wire is always engaged to the alternator - the only thing stopping this from being a dead short to begin with is the diodes, so if one backfeeds it's a done deal...

Darryl brought up the car radio and someone leaving it on and it not being wired right --- but it too can be triggered EVEN if wired correctly simply by either diode malfunction (due to their still being power ran to it to run the clock at all times) or corroded circuit board, I repaired a Kenwood with this problem - was taking the system down, tracked it down to the circuit board --- cleaned all the corrosion up and replaced a couple surface mount resistors because they were too far gone,,, problem solved - talked to the customers and asked them what could have possibly happened because their seemed to be a sticky substance that started the corrosion - get a giggle out of both of them --- seems as though about a year earlier "the bride" was drinking a coke and hit a massive bump - the drink popped it's lid in the cup holder which resides directly above the kenwood,,,

"do you think that could have done it?" they ask,,, why yes - yes i do... But --- that was constant draw,,, the puzzle in the OP stated "no draw"

But technically that not does not exclude an alternator with bad diodes... they can test no draw what-so-ever, then you turn your back and they drain the battery...

The pulley being the wrong size does not fit the puzzle, first off they said "all the components in the electrical system are just fine" How can you even make that statement if you never checked the replacement alternator's charge values at Idle with the headlights on?

[lynnl]

Oh lighten up AKB! The puzzlers they presented on their radio program weren't intended as an advanced mechanics course. They were for the amusement and entertainment of the rest of us "hillbillies."

[GordonL]

Also be aware that the show is a rebroadcast of shows 30 to 40 years ago when most shops did not have the test equipment available today. We are talking Joe's Garage operating out of his garage in his back yard. Most of the vehicles in question are 1980 and 1990 vintage.

[A.K. Boomer]

Puzzles simple or not should still have pieces that fit together,,, and does not take anything other than a volt meter to do an alternator check nothing fancy and they have been out for quite sometime,,, Iv never once replaced an alternator without at least checking it's voltage output @ idle... how could you replace an alternator without even doing that? just bolt it on and call it good? to me that would be unheard of unless your a total hack... after the alternator was replaced the pulley error should have been immediately caught in the test, would never have led to any kind of a "puzzle"....

[tomato coupe]

Next up: A critical assessment of lightbulb jokes.

[lynnl]

AKB, when someone starts a joke ..."This duck walks into a bar and says to the bartender 'blah...blah.. ...'," I bet you immediately pipe up and point out that ducks can't talk?

[A.K. Boomer]

AKB, when someone starts a joke ..."This duck walks into a bar and says to the bartender 'blah...blah.. ...'," I bet you immediately pipe up and point out that ducks can't talk?

Oh so now it's a joke and not I quote; "an interesting puzzle" I think i get it - jokes on you then right?

[tomato coupe]

Oh so now it's a joke and not I quote; "an interesting puzzle" I think i get it - jokes on you then right?

Did you ever listen to the show?

[A.K. Boomer]

Did you ever listen to the show?

I tried a couple of times, had to turn it off, i think one of the times they started off with some useful information and then got off track and another time they were just totally off track... it upset me so i turned it off...

[tomato coupe]

I tried a couple of times, had to turn it off, i think one of the times they started off with some useful information and then got off track and another time they were just totally off track... it upset me so i turned it off...

I think you missed the point. It wasn’t an ‘information’ show, it was a comedy show.

[A.K. Boomer]

I think you missed the point. It wasn’t an ‘information’ show, it was a comedy show.

I think you need to go back and re-read the very first sentence in the OP,

"I'm subscribed to get the weekly puzzlers by email, and here's an interesting one."

this does not sound like comedy to me - does it to you? does "interesting puzzle" mean comedy to you? if so guess were just on a different page with this....

[reggie_obe]

I think you missed the point. It wasn’t an ‘information’ show, it was a comedy show.

It certainly wasn't a show aimed at ASE techs.

[A.K. Boomer]

For those interested --- I have a elementary "puzzler" sitting outside --- toyo/taco came in on the hook yesterday, "will not start" customer says on the phone they think the battery's dead,

it was about 4.30pm, I was done working for the day but wanted to quickly diagnose it to know what im up against for today because she lives in the mountains and can catch a ride to town later today....

so here you go, by the time you get done diagnosing this you should be left with only two simple choices, but one of the choices can be eliminated with common sense knowledge of basic operating principles,,,

Here's my 5 minute diagnoses that lead me to the answer - mind you - I don't have proof positive of the answer yet as I have not "fixed" the problem - but im very confident I know what's going on...

First things first --- I pop the hood and test the battery voltage --- it's 12.59 volts,,, its not the battery, secondly - I look at the batterys connections --- both positive and negative are clean as a whistle... ok ---------- head to the cab for a start, I instantly hear the small underdash relay click every time I turn the key to the start position, a millisecond after I hear that it's getting the "big boy" under the hood involved too, meaning the starter solenoid,

So i go into repeats with it - the vehicle is a 5 speed --- has to have the clutch pedal depressed to engage the starter - so I just do about 6 tries with the key and clutch pedal depressed, hear the "double click" of the relay and solenoid, then for the heck of it I lock the key in the start position and use the clutch pedal as a switch just to test it's integrity, all 6 more double clicks,,,

I already know it's one of two possibilities as most of you already do, but - im not content with that - I need to know more ---- so I go into a spastic engagement mode of repetitive attempts and finally get the starter to engage --- it turns over with ample "gusto" but then quits about 3 engine revolutions, was actually surprised the vehicle did not start --- I did want to get it started cuz the tow truck driver kinda left if too far out in the street so I kept at it again - and yet again got it to engage - but yet again about 3 revolutions and then it disengages ! damn and still no start,,, then third times a charm, get it to keep cranking and finally get it to clear its throat and start --- move the vehicle and re-park it,,,

I know it's the starter as most all of you do to --- but now I know what component in the starter is bad... the two choices were either brushes or solenoid contacts,,,

How did I determine it was one or the other?

[tomato coupe]

I think you need to go back and re-read the very first sentence in the OP,

"I'm subscribed to get the weekly puzzlers by email, and here's an interesting one."

this does not sound like comedy to me - does it to you? does "interesting puzzle" mean comedy to you? if so guess were just on a different page with this....

That’s why I asked if you ever listened to the show. It was comedy. (And, quite good comedy at that.)

[A.K. Boomer]

That’s why I asked if you ever listened to the show. It was comedy. (And, quite good comedy at that.)

There was comedy thrown into the mix, but the "puzzler" questions were for real were they not? at least that's what the OP basically stated....

If not then the puzzler questions were a joke and ended with a "punch line" I really don't think that was the case was it???