I looked thru the factory WSM.....nothing in detail on this, other than what I sent you. It kinda makes sense...they'd just have a tech change it out.

Thanks for looking, Ed...

Best,

Doyle

that's obviously a single layer board Doyle you should be able to draw that out pretty quick as long as that transisitor follows standard BCE format for the transistor .. but ya never know with these Germans ..

Yes,.ICE,..It's quite a simple circuit....for sure. No mysteries.

Have to watch our for Germanium transistors!~

Doyle

It looks like I've part #s on the transistors,..so we'll see what we get...

Just to post from PP from a great fellow who's participating within this issue..

His post will be attached (edited, for just the post from HELLA)

Thanks everyone!


Doyle

I'm thinking of the following (and I'm no mechanic):

My big boat anchor Porsche battery has been in there well past 7 years......it's really time to replace. I've been tracking the voltage each morning (precrank), via thew radar detector readout from the cig connection (it's within 1/10 DCV from the battery measurement0....I've noticed some voltages that don't reflect 100% charge so time draws near...as to DRIVING,..the voltage readout is fine (within specs),..with the VR doing it's job based on what it needs to do........can be temp dependent,..can be time dependent (2 days-down,..vs. 5 days down)....she's fine.......SO:

In all cases, the cirscuit #2 requirement for it's "triggered" DC level is NOT an issue within my car. She'll (easily) see +13.0 VDC at all times,..at ALL stages....SO,..the input data is good to go. I suspect the integral circuitry would be engineered to accomodate the noted contention of various level trip points...can't wait to get this sketched out!

One thing's FOR SURE: this old (original) electrolytic cap will be changed (on principle, as they don't get better with age),..with a lofty voltage rating on the new one.

Patience is NOT a virtue.

Doyle

Before frostbite set in,..I did check component values of all resistors, diodes,..cap showed charging but quite slow......she's almost 22 years old,..whatdoyaexpectfromaelectrolytic? All checked within tolerances. (cap will go.

I do have transistor testers, curve tracers, etc. within my shop but was overcome with coldness to make sense of efficiencies....could have easily checked those transistors out,..even by the nice fire tonight....MAN,..I HATE COLD!!!!!!!

AGAIN,..I'll get to the MANUAL closing of relay #2 and see if she delivers the goods across her contacts,..if the contacts prove interfering, I'll simply jumper the contact points and look for epiphany.......easy to diag a frikin coil/relay ass'y,....(YAWN]..........

Soon,...so soon.

Best to all,...

Doyle

Sharing a bud's post from PP: Just more data,.....

http://forums.pelicanparts.com/porsc...es-unplug.html

Best,

Doyle

I'm thinking FIRE ALL OF THE ELEMENTS UP AT FIRST then one would decrease voltage on selected (outer) elements..? When done, cut the damned switch off....

We'll get to the bottom of this..

Doyle

not to be a distraction, the heated rear mirrors are in there somewhere IIRC.

Doyle,
When you get the Txistor P/Ns, send them to:

xref@onsemi.com

They will get you a cross to the current devices and then you can buy them at Digikey or Avnet express.

Outside mirrors?

Yes, they are, Bird.

Through a 25 amper fuse to the actual switch.....This will, in turn, provide a straight DC voltage path (through it's contacts), to the sideview mirrors. One VERY important footnote (970-55/Bentley) is that the pwr mirror switch gets its ground from a tap off at the left outside mirror!!!!. In no cases are transistors used !!!!!!!!!!!!

On with the defog circuitry......(with transistors).......

Best to you and yours' Bird!

Doyle

I usually can cross anything..but DO appreciate the email address!!!!!!!!!!!!!!!!

Best,

Doyle

Gerry,..being off today, I couldn't resist....

As to that email you posted, might I ask a few questions? Tobetter clarify his offerings?

"the first stage (center elements) of the heating is operational at 10.5 VDC",..I ask "measured where"?

the second stage )upper/lower elements) is working at 12.8 VDC......I ask, "measured where"?

In BOTH cases, my system voltage is well above that....I think this to be irrelevant, as the circuitry is controlling the "ratios"... and we WON'T know, until we've the schematic on the circuit!!!!!!!!

FUN!!!!!


Doyle