Home  |  Forums  |  914 Info  |  Blogs
 
914World.com - The fastest growing online 914 community!
 
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG. This site is not affiliated with Porsche in any way.
Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners.
 

Welcome Guest ( Log In | Register )

 
Reply to this topicStart new topic
> Turn key, battery goes flat, ignition switch smoky.
jaredmcginness
post Nov 30 2020, 08:25 PM
Post #1


Member
**

Group: Members
Posts: 323
Joined: 12-June 19
From: Baltimore
Member No.: 23,209
Region Association: MidAtlantic Region



Me again.
It’s gonna be one problem post a day, until next years Octeener fest. (IMG:style_emoticons/default/idea.gif)

So close here to firing this motor (in the car)(works fine outside of it)
I’m thinking I have a short somewhere in the ignition, but everything seems to check out.

Notes:

Early car, early VW style switch. (After market)
Turn key, ACC works fine, fuel pump relay clicks, all electrics work.
12v to coil, 12v to starter, power supply relay is good.

Turn key to run, Nothing - power goes flat, as long as I hold the key down.

Messing around a bit, tried again and the ignition switch/column starts
smoking and the IGNS wires are warm.

I believe once she smokes she’s done.

I’ll buy a new switch tomorrow, but I’m trying to probe if this sounds like more than a switch.



All my wiring matches the bowlsby pages. Battery is new.
Switch was new (but probably Taiwan crap), new ground to battery and new ground strap. Cleaned every ground I can find. Does not even considering the idea of cranking.
Starter cranks fine when manually jumped.


Now that my smoke is out, queue the ‘Replacement Can’ comments. (IMG:style_emoticons/default/bye1.gif)

User is offlineProfile CardPM
Go to the top of the page
+Quote Post
jaredmcginness
post Nov 30 2020, 08:49 PM
Post #2


Member
**

Group: Members
Posts: 323
Joined: 12-June 19
From: Baltimore
Member No.: 23,209
Region Association: MidAtlantic Region



Ahh yes, found it. I’ll need to add this to my order.

(IMG:http://www.914world.com/bbs2/uploads/post-22428-1558925713.jpg)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Spoke
post Nov 30 2020, 09:07 PM
Post #3


Jerry
*****

Group: Members
Posts: 6,438
Joined: 29-October 04
From: Allentown, PA
Member No.: 3,031



QUOTE(jaredmcginness @ Nov 30 2020, 09:25 PM) *

Early car, early VW style switch. (After market)
Turn key, ACC works fine, fuel pump relay clicks, all electrics work.
12v to coil, 12v to starter, power supply relay is good.


I believe there are only 3 positions for the ignition switch: Off; Running; and Start.

So when you "Turn key", this is to the Running position, correct? The 12V to the starter is measured on the large wire from the battery, correct? 12V on the large wire is constant regardless of the key position. The smaller yellow wire comes from the ignition key when in the "Start" position and puts 12V on the yellow wire to the bendix on the starter.

QUOTE

Turn key to run, Nothing - power goes flat, as long as I hold the key down.
Messing around a bit, tried again and the ignition switch/column starts
smoking and the IGNS wires are warm.


You mean when you go to the "Start" position, correct? In the Start position the yellow wire on the starter should be powered. This wire goes from the ignition switch to the relay board then to the starter. Try disconnecting the harness on the relay board from the cabin and see if the power goes flat.

User is offlineProfile CardPM
Go to the top of the page
+Quote Post
jaredmcginness
post Nov 30 2020, 09:47 PM
Post #4


Member
**

Group: Members
Posts: 323
Joined: 12-June 19
From: Baltimore
Member No.: 23,209
Region Association: MidAtlantic Region



Correct. When I turn key to Run, I have power. When I turn from Run to Start, it goes flat.

I will remove the cabin harness from relay (the 14 pin one, right?)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Mikey914
post Nov 30 2020, 11:39 PM
Post #5


The rubber man
**********

Group: Members
Posts: 10,763
Joined: 27-December 04
From: Hillsboro, OR
Member No.: 3,348
Region Association: None



Check the switch itself. There were some crappy ones made that would allow the switch to ground out and melt it.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
mepstein
post Nov 30 2020, 11:46 PM
Post #6


914-6 GT in waiting
***************

Group: Members
Posts: 15,824
Joined: 19-September 09
From: Landenberg, PA/Wilmington, DE
Member No.: 10,825
Region Association: MidAtlantic Region



Do you still have the switch I gave you. Does it work?
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
jaredmcginness
post Dec 1 2020, 05:15 AM
Post #7


Member
**

Group: Members
Posts: 323
Joined: 12-June 19
From: Baltimore
Member No.: 23,209
Region Association: MidAtlantic Region




Sound about right then Mikey, I think this was one of the $35 crap switches with thinner gauge wires. Hope this is the issue.

QUOTE(mepstein @ Dec 1 2020, 12:46 AM) *

Do you still have the switch I gave you. Does it work?

I have the tumbler and key installed, I don’t recall there being a switch. But the tumbler works excellent.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Superhawk996
post Dec 1 2020, 06:42 AM
Post #8


Advanced Member
****

Group: Members
Posts: 2,353
Joined: 25-August 18
From: The Motor City
Member No.: 22,428
Region Association: Galt's Gulch



QUOTE(jaredmcginness @ Nov 30 2020, 09:25 PM) *


I’m thinking I have a short somewhere in the ignition, but everything seems to check out.




Me too.

You posted a lot of other good info on what parts you have but the only thing that really matter is wheter or not the Digital Multimeter says things check out.

DMM and wiring diagram are your friend. All else is speculation. Let me find the link to half split troubleshooting method I've previously posted.

Post #6
http://www.914world.com/bbs2/index.php?showtopic=340700
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
jaredmcginness
post Dec 1 2020, 07:48 AM
Post #9


Member
**

Group: Members
Posts: 323
Joined: 12-June 19
From: Baltimore
Member No.: 23,209
Region Association: MidAtlantic Region



QUOTE(Superhawk996 @ Dec 1 2020, 07:42 AM) *



the only thing that really matter is wheter or not the Digital Multimeter says things check out.

DMM and wiring diagram are your friend. All else is speculation.


I've never heard of the half split method. I just read a few articles and will apply this tonight. I Prime same-day ordered a better DMM with continuity. Probably much over due from the POS $7 Harbor freight one I've had for years.

Always appreciate your advice.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
VaccaRabite
post Dec 1 2020, 08:56 AM
Post #10


En Garde!
**********

Group: Admin
Posts: 12,366
Joined: 15-December 03
From: Dallastown, PA
Member No.: 1,435
Region Association: MidAtlantic Region



Do you have a solenoid at the starter to handle the big load for starting the car? If not, do that.

As stock, all the power for starting the car goes all the way from the battery to the ignition switch and the back to the starter. The solenoid lets you run a thick cable from the battery to the starter motor and keeps the switch at low amperage. Most of us use a Ford solenoid, the wiring is very simple and they are CHEAP. I have mine bolted to the back of the engine tins so it sits right next to the starter.

This won't fix you immediate problem, but will keep your starter switch from melting in the future.

Zach
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Superhawk996
post Dec 1 2020, 09:19 AM
Post #11


Advanced Member
****

Group: Members
Posts: 2,353
Joined: 25-August 18
From: The Motor City
Member No.: 22,428
Region Association: Galt's Gulch



QUOTE(VaccaRabite @ Dec 1 2020, 09:56 AM) *


As stock, all the power for starting the car goes all the way from the battery to the ignition switch and the back to the starter.

Zach


Be careful with this - I'll modify:

As stock, all the power for starting the car goes all the way from the battery to the ignition switch and the back to the OEM Starter SOLENOID.

The starter motor current (upwards of 100 amps or more) is not drawn through the yellow wire via the ignition switch. The yellow wire handles the OEM starter solenoid current not the actual starter motor current.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
jd74914
post Dec 1 2020, 09:46 AM
Post #12


Its alive
****

Group: Members
Posts: 4,508
Joined: 16-February 04
From: CT
Member No.: 1,659
Region Association: North East States



QUOTE(Mikey914 @ Dec 1 2020, 12:39 AM) *

Check the switch itself. There were some crappy ones made that would allow the switch to ground out and melt it.

(IMG:style_emoticons/default/agree.gif)

I had this happen with 2 replacement switches before putting in a NOS. (IMG:style_emoticons/default/headbang.gif) Once while driving with the top on and windows up-couldn't believe how fast plastic smoke filled the cabin.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
fixer34
post Dec 1 2020, 04:24 PM
Post #13


Member
**

Group: Members
Posts: 481
Joined: 16-September 14
From: Chicago area
Member No.: 17,908
Region Association: Upper MidWest



QUOTE(jaredmcginness @ Nov 30 2020, 08:49 PM) *

Ahh yes, found it. I’ll need to add this to my order.

(IMG:http://www.914world.com/bbs2/uploads/post-22428-1558925713.jpg)

This won't work anyway. The smoke will go backwards since it is positive earth (ground).
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
mepstein
post Dec 1 2020, 05:06 PM
Post #14


914-6 GT in waiting
***************

Group: Members
Posts: 15,824
Joined: 19-September 09
From: Landenberg, PA/Wilmington, DE
Member No.: 10,825
Region Association: MidAtlantic Region



QUOTE(fixer34 @ Dec 1 2020, 05:24 PM) *

QUOTE(jaredmcginness @ Nov 30 2020, 08:49 PM) *

Ahh yes, found it. I’ll need to add this to my order.

(IMG:http://www.914world.com/bbs2/uploads/post-22428-1558925713.jpg)

This won't work anyway. The smoke will go backwards since it is positive earth (ground).

Bob Russo has a big sign on the Mirage race car for positive ground.


Attached image(s)
Attached Image
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
jaredmcginness
post Dec 1 2020, 06:32 PM
Post #15


Member
**

Group: Members
Posts: 323
Joined: 12-June 19
From: Baltimore
Member No.: 23,209
Region Association: MidAtlantic Region



OK.



Guys, as usual I step back into my question threads, solved, with my head hanging low.


I tested continuity on the relay board. 100% all around. Cleaned up the ground bundle really well... Nice to know. But still leaves me hanging.


The new ignition switch arrives. (lucky to have found one in town (BaltAuto - $59)

I start stripping down the column.... Low and behold.....



(IMG:http://www.914world.com/bbs2/uploads_offsite/i.imgur.com-23209-1606869157.1.jpg)


You cannot make this crap up. I installed that switch over a year ago, actually one of the first things I did when I bought the car
(P.O. Drilled the ignition out) Used a cheapo ebay switch - did not check my work.

You can imagine my laugh - and face when I saw this. It could not be MORE grounded to the body, you can actually see through it.


Feel free to flame me.

What I have learned:
-The half split method.
-Every ground I can find is now clean.
-Relay board is in good shape.
-I've tested every relay I own.
-I strongly dislike early switches.



For the guys reading this down the road. Dont buy thee cheapo $22 switch.


(IMG:http://www.914world.com/bbs2/uploads_offsite/i.imgur.com-23209-1606869157.2.jpg)


Here are the differences:

Ebay (jbugs)($22) vsU.S. Standard #403 Ign. Switch ($59)

Ebay is junk clamped, wires are loosely attached, each wire has broken strands. Fits loose in the column.

US Standard #403 Soldered connection, Nice and tight fit in the column. The actual switch mechanism is tighter. Also... Made in Germany?


(IMG:http://www.914world.com/bbs2/uploads_offsite/i.imgur.com-23209-1606869157.3.jpg)


I will hang the old switch above my work bench, to remind me to think and check the easiest thing first. The root of the problem.


Thank you for the help and responses. The car cranked, first try.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
FlacaProductions
post Dec 1 2020, 07:00 PM
Post #16


Senior Member
***

Group: Members
Posts: 775
Joined: 24-November 17
From: LA
Member No.: 21,628
Region Association: Southern California



I always appreciate a graceful recovery. Nice work - glad it ended well!
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Superhawk996
post Dec 1 2020, 07:08 PM
Post #17


Advanced Member
****

Group: Members
Posts: 2,353
Joined: 25-August 18
From: The Motor City
Member No.: 22,428
Region Association: Galt's Gulch



Good job finding that pinched wire! No shame there.

Would have been a shame to start guessing at fixes, modifying wiring, adding solenoids, etc., just hoping for a fix.

We all learn by our mistakes. Been there done that!

I'm going to suggest that you do one more homework reading assignment on half split method. Here's the punch line to encourage you to read it.

"Lesson learned: do not take short cuts, do not assume the part you can easily test is the part that is broken, and do not assume you have found the problem the first time you find something that does not look right. "

So unless you've fully verified your new switch and repaired wire circuit to have low resistance continuity with a DMM all the way back to the starter solenid - You're not done.

https://rule11.tech/troubleshooting-half-split/
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Tom
post Dec 3 2020, 01:43 PM
Post #18


Advanced Member
****

Group: Members
Posts: 2,131
Joined: 21-August 05
From: Port Orchard, WA 98367
Member No.: 4,626
Region Association: None



Superhawk996,
In the military we learned the divide and conquer method. Essentially the same as what you learned as the half split method. And if one does not understand what the complete circuit is composed of, and how it is supposed to work, you are starting in a hole and digging the hole deeper. I have seen it too many times where someone working on an electrical/electronic circuit and does not understand the circuit and ends up making the problem worse.
A good set of wiring diagrams and or schematics is a must. The Haynes manual wiring diagrams have lead many to make the problem worse. Too small and too easy to jump a trace by one wire, ending up with measurements that make no sense.
One more tip: when using a multimeter, always test the meter on a known good power source of the same value you are checking for both before and after your readings have been taken. Just imagine taking reading for an hour or two and not getting anything that makes sense and then trying the meter on your known good 12V battery and the reading is 3 volts. Just wasted a couple of hours.
Tom
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Costa05
post Dec 3 2020, 03:40 PM
Post #19


Member
**

Group: Members
Posts: 224
Joined: 27-October 16
From: Phoenix, Arizona
Member No.: 20,535
Region Association: Southwest Region



Here is my switch I just replaced last week. Notice the crack in it. Had similar problem as you but no short/smoke. Also putting in new solenoid in engine bay to lighten the load going to my new ign switch as others did.Attached Image
User is offlineProfile CardPM
Go to the top of the page
+Quote Post

Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 



- Lo-Fi Version Time is now: 23rd January 2021 - 01:49 AM