Puzzler : yet another “my car died while driving” post

[Bukowski]

I have to add to the Internet, yet another “my car died while driving” post. In this case, I’m calling it a Puzzler, as you may recall from that bogus show Car Talk - and it being a Saturday, what better time - but really because there IS and answer, and I’ll post it later - Pelican style.

First, a back story : I have a dying fuel pump check valve, as evidenced by having to hold the start key down for ~20 seconds - otherwise, 2.5 bar of pressure, steady. Front strut is worn out completely - vibrates a lot if it hits the bumps. Also, put a brand new Bosch alternator in 1 year ago, new Sears battery 2 years ago.

Here’s the story:

Driving my late (1987) model 944 NA along just fine, from home to highway - no problems. I just cant wait to get to the the All England Mustard Festival and All-You-Can-Eat Vegamite-Lutefisk Soufflé Bingo Night.

Then it hits the stop-and-go traffic - no reason to worry ever before... UNTIL NOW.....

Car jerks a bit, surges forward, I manage to hobble over to the breakdown lane before stopping completely. Lights not on. Can’t start. Hazard lights sort of work but really mostly clicking the relay - not much light.

Tow the heap back to the garage, sit down, and stare into The Void.

Since the lights don’t come on, I figure to take the battery out and trickle charge it overnight. Charger lights are green the next day - disconnect battery, let sit disconnected another night. Next morning : yellow charging light after putting it on the trickle charger ... all day ... ALL NIGHT.... when is this going to end? It only took overnight yesterday! Charger light is green the next day. LEAVE it trickle charging until I’m REALLY ready to use it.

The question is : what happened?

And what do you fix first?

Was the alternator, being the first alternator installed by this first-time 944 owner, installed wrong?

Did the strut have something to do with it? All that vibration shaking the knuckle assembly like crazy?

Should Sears get a nasty call about their cheap products, and how they don’t make them like they used to?

Or something else in the whole pile of junk sitting in the garage now?

Meanwhile, what if the gas gets old before you figure it out?

I’ll post the answer - yes, a genuine answer - after I see some replies from the group.

And lastly, I’d like to dedicate this Puzzler to Clark Fletcher, whom until now I never knew served in the United States military - I thank him for his service - to country, to citizens, to families, and to 944 owners.

[djnolan]

It sounds like your alternator failed and stopped charging the battery and as you kept driving the battery became run down and could no longer run the numerous electrical items including the DME, coil, injectors, fuel pump, and if it was at night the lights, and if it was in the south the A/C?

[Bukowski]

Morning drive - lights on.

Original A/C installed, put in new condenser (see posts here), previously charged, then rapidly lost charge. Haven’t tried to get it working again.

Blower fans probably running too when it happened.

Trusty Harbor Freight battery/alternator tester consistent results after installation of alternator:
Alternator : “yellow/good” (2nd from highest LED) 13.5V?
Battery : “green” 13.5V
Essentially good battery/alternator, but not necessarily immediately before the sudden death

[thomasryan]

dry cell

[djnolan]

Don't let the battery sit too long undercharged.

[Jfrahm]

Loose battery shorted out on the hood.

[Bukowski]

Nobody got it yet. It’s a very specific answer, and I HOPE this will help 944 owners in that regard, but perhaps only late models.

And ... well, I’ll just say it’s not the battery. Battery is fine.

And the alternator was fresh from Bosch a year ago.

[v2rocket_aka944]

ground strap from battery to chassis/chassis to block OK?

[944 Ecology]

Alternator belt too loose.

[Slam]

I'll play: alt mount or AC compressor mount pivot bolt broke and alt belt departed or loosened. If alt is fine and batt is fine then whatever the problem is, it has to be a charging issue.

I guess I'm just echoing George, but adding the reason for belt failure. Those pivot bolts can twist and break if they're not backed off while you're tensioning the alt belt.

[Bukowski]

Originally Posted by Slam

I'll play: alt mount or AC compressor mount pivot bolt broke and alt belt departed or loosened [....]Those pivot bolts can twist and break if they're not backed off while you're tensioning the alt belt.

Good answer

I’ll say that I specifically followed Clark’s (Porsches Be Under Him... )guidance to LEAVE the belt tension ALONE ...

But yeah, then what if it’s STILL become loose... it might be!...

[djnolan]

I think I should get credit if that is the case, whether the alternator fell off or died internally...

Originally Posted by djnolan

It sounds like your alternator failed and stopped charging the battery and as you kept driving the battery became run down and could no longer run the numerous electrical items including the DME, coil, injectors, fuel pump, and if it was at night the lights, and if it was in the south the A/C?

[Bukowski]

These are good answers, but it’s less about some component just wearing out like normal, but more to do with the layout of the components ....

For the record I don’t have any prizes to give out...

[jhowell371]

Something like the top of the worn out strut moved a bit and got into the wiring loom shorting something? Saw it happen to Clarkson in a 928 on "Top Gear".

[onZedge]

I'll play: The cables from the battery to the starter/bell housing chaffed and are shorting?

[Bukowski]

Originally Posted by onZedge

I'll play: The cables from the battery to the starter/bell housing chaffed and are shorting?

How would that explain fine driving for months back, fine highway driving one day, then when the stop-and-go traffic begins the car barely makes it to the breakdown lane?

[Bukowski]

Without further ado, and ... well, I'm busy. This is a hastily written solution - and it is a true solution - to my puzzler:


I also got a cool little gadget - and I don't think Pelican carries this, so I'm out on a limb if this is a faux pas - called an Innova iequus - something-or-another, plugs in the cigarette lighter (12V power socket in modern terms). Let's you watch some sort of voltage in real-time as-you-drive.

OK so a tiny story - after the "sudden death", I let the 944 recuperate in the garage. Charged the battery (I can't recall what I wrote up there ^^^ can't be bothered to read right now)... all good. started up. looked at the Innova meter. looks ok. drove around town a while - like 30 min. got a feel for the lights/numbers. mostly ok. voltage dips down when using things like lights, but its stable.

then I got back home, sitting in the driveway, wondering what the problem is...

and then...

do you know what happened then?

THE COOLING FANS CAME ON.

voltage dipped down immediately, and CONTINUED TO DECREASE.

going very low.. until HOLY S get this in the garage and shut it off.

... and as if I was driven by a mysterious outside force, I promptly opened the hood (as any good 944 owner does on a regular basis...) and looked directly here:



... you know exactly what that is.

that's the solution. those damn wires - with the brittle plastic (and brittle only on the exterior, not underneath and inboard of the firewall / car interior) - had slowly, but surely, from perhaps extra vibrations (recall, the shock absorber is toast), snuggled right over to the edge of the blower motor housing metal screen, chafed bit by bit, until one day - WHEN THE COOLING FANS CAME ON - short circuit.

so I urge every 944 owner - go out right now and at least slap some electrical tape on these wires. it will save you TONS of grief.

... yes there are nice writeups on replacing the exterior portion of these wires, and especially from some kind citizens of the Pelican forum (apologies, I can't recall the name or provide a link), so you can look into that if you like.

Personally, I'd like to do The Best Radiator Resistor Wire Replacement Of All Time, but til then, electrical tape.

Thanks for playing... I don't have any prizes!...

[onZedge]

yay!

[Waz951]

Originally Posted by Bukowski

... yes there are nice writeups on replacing the exterior portion of these wires, and especially from some kind citizens of the Pelican forum (apologies, I can't recall the name or provide a link), so you can look into that if you like.

I'm sure a few people will be looking for the how to so if you happen to find it definitely post it.

[Bukowski]

TechnoDuck !!!

Cooling fan resistor wiring for 85.5+ cars