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 )

4 Pages V < 1 2 3 4 >  
Reply to this topicStart new topic
> battery connection screw up
dt4
post Feb 11 2020, 02:32 PM
Post #41


Member
**

Group: Members
Posts: 148
Joined: 26-May 19
From: England
Member No.: 23,161
Region Association: England



its a very slow errr......long pause...... errr .......click
(IMG:style_emoticons/default/smile.gif)

I have looked the wiring over and cant see anything untoward
As the fuel pump can be heard running and there is small sign of life in as much as there is power getting to the starter but either not enough to turn it over or the starter has a problem, could there be anything on the relay board that could have been effected?
I notice there is a circuit board on the underside, could a track have been burnt out? (there isnt any sign to suggest this, i am just fishing for ideas)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
ejm
post Feb 11 2020, 05:28 PM
Post #42


I can see the light at the end of the tunnel
****

Group: Members
Posts: 2,462
Joined: 3-February 03
From: Massachusetts
Member No.: 224
Region Association: None



QUOTE(dt4 @ Feb 11 2020, 03:32 PM) *

could there be anything on the relay board that could have been effected?
I notice there is a circuit board on the underside, could a track have been burnt out? (there isnt any sign to suggest this, i am just fishing for ideas)


No. Since the solenoid engages when you turn the key to start the only circuit relevant on the relay board is good.

The connections you haven't tested are where the battery cables are crimped onto the terminals at either end. These can and do corrode internally. I've used jumper cables from the battery terminals to a ground near the starter and the starter battery cable post to provide an alternate current path. If the engine spins faster you have a cable problem.

If the starter was working before this issue I would look into this before pulling or replacing the starter.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
ctc911ctc
post Feb 11 2020, 07:20 PM
Post #43


Member
**

Group: Members
Posts: 364
Joined: 9-June 18
From: boston
Member No.: 22,206
Region Association: North East States



QUOTE(ejm @ Feb 11 2020, 06:28 PM) *

QUOTE(dt4 @ Feb 11 2020, 03:32 PM) *

could there be anything on the relay board that could have been effected?
I notice there is a circuit board on the underside, could a track have been burnt out? (there isnt any sign to suggest this, i am just fishing for ideas)


No. Since the solenoid engages when you turn the key to start the only circuit relevant on the relay board is good.

The connections you haven't tested are where the battery cables are crimped onto the terminals at either end. These can and do corrode internally. I've used jumper cables from the battery terminals to a ground near the starter and the starter battery cable post to provide an alternate current path. If the engine spins faster you have a cable problem.

If the starter was working before this issue I would look into this before pulling or replacing the starter.

(IMG:style_emoticons/default/agree.gif) (IMG:style_emoticons/default/agree.gif) (IMG:style_emoticons/default/agree.gif) (IMG:style_emoticons/default/agree.gif) (IMG:style_emoticons/default/agree.gif)

I would run the jumper cable from the negative terminal first - battery to starter - this will confirm that the chassis is working as a ground conductor or not.

Next

If there is no change, take the cable off completely

Then the Positive side:

Connect the jumper cable to the starter on the big nut, where the battery cable connects (once this is done the other end of the cable is HOT - make sure it is not touching anything), then connect to the positive - Double Check- lug of the battery. Then turn the key!

If there is no change to in either test,,,,this is getting interesting!

User is offlineProfile CardPM
Go to the top of the page
+Quote Post
porschetub
post Feb 11 2020, 07:36 PM
Post #44


Advanced Member
****

Group: Members
Posts: 3,457
Joined: 25-July 15
From: New Zealand
Member No.: 18,995
Region Association: None



QUOTE(dt4 @ Feb 12 2020, 09:32 AM) *

its a very slow errr......long pause...... errr .......click
(IMG:style_emoticons/default/smile.gif)

I have looked the wiring over and cant see anything untoward
As the fuel pump can be heard running and there is small sign of life in as much as there is power getting to the starter but either not enough to turn it over or the starter has a problem, could there be anything on the relay board that could have been effected?
I notice there is a circuit board on the underside, could a track have been burnt out? (there isnt any sign to suggest this, i am just fishing for ideas)

My advise maybe suspect as electrical work is a real art on older cars as you are always chasing issues.
You could try to crank the starter manually by jumpering the hot lead to your yellow solenoid wire,try that and may prove you have an ignition switch issue which is very possible with these cars.
Yes you can bench test the starter after you have done the above, (IMG:style_emoticons/default/beer.gif)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
dt4
post Feb 12 2020, 01:32 AM
Post #45


Member
**

Group: Members
Posts: 148
Joined: 26-May 19
From: England
Member No.: 23,161
Region Association: England



I guess I can make this easier to get the jumper leads to the starter by putting the battery under the car? so not having to thread them down and around and also not as likely for the positive to contact something it shouldn't?

I am clear on which is the positive for the starter

could some one show which is the negative or is it obvious once I get back under and take another look?

Many thanks for the pointers chaps (IMG:style_emoticons/default/thumb3d.gif)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
dt4
post Feb 12 2020, 01:36 AM
Post #46


Member
**

Group: Members
Posts: 148
Joined: 26-May 19
From: England
Member No.: 23,161
Region Association: England



Attached Image
I took a photo from ebay, I am guessing the negative is the terminal that is not the positive (IMG:style_emoticons/default/biggrin.gif)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
914Greg
post Feb 12 2020, 03:15 AM
Post #47


Newbie
*

Group: Members
Posts: 14
Joined: 17-November 19
From: Australia
Member No.: 23,647
Region Association: None



Technically speaking when connecting and disconnecting jumper cables the negative terminal is the last fitted and first removed and not connected to the battery post.
The reason being if there is a mistake with polarity or a dead short there is the potential for sparks, if this happens at the battery there is a possibility of an explosion caused by sparks igniting battery gases.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
ctc911ctc
post Feb 12 2020, 11:04 AM
Post #48


Member
**

Group: Members
Posts: 364
Joined: 9-June 18
From: boston
Member No.: 22,206
Region Association: North East States



QUOTE(dt4 @ Feb 12 2020, 02:36 AM) *

Attached Image
I took a photo from ebay, I am guessing the negative is the terminal that is not the positive (IMG:style_emoticons/default/biggrin.gif)


We still have some conceptual work to do.

The entire car - everything metal is negative. So, the negative lead should be connected to the starter chassis or a point close to the starter. See the red circle in the picture.

We are testing the connections from the neg term on the battery, through the car to the starter, there is a ground strap that connects the engine/trans to the chassis - this may be a problem.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Spoke
post Feb 12 2020, 12:36 PM
Post #49


Jerry
*****

Group: Members
Posts: 6,217
Joined: 29-October 04
From: Allentown, PA
Member No.: 3,031



QUOTE(dt4 @ Feb 12 2020, 02:36 AM) *

Attached Image
I took a photo from ebay, I am guessing the negative is the terminal that is not the positive (IMG:style_emoticons/default/biggrin.gif)


The lug closest to the starter body is the positive power for the actual starter motor. The lug towards the top of the picture is the connection to the battery. The bendix (small cylinder above the starter motor) is a contactor which connects the 2 lugs together electrically to turn the starter motor. The bendix also pushes out the gear which engages the flywheel so the starter motor will turn the flywheel.

The small electrical tab on the bendix is the power (from the ignition switch) to power the bendix.

Personally I wouldn't try to connect any wires or jumper cables to the starter. I would inspect the wires and if anything, measure the voltage on the lug from the battery when the starter is engaged.

Once you have the voltage at the starter, do the same measurement at the battery measuring from the positive terminal CLAMP and at the actual battery terminal. This will test the clamp and wire to make sure it is electrically sound.

Also check the ground strap on the battery to chassis AND the ground strap on the transmission. All cables should be clean and secure.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
dt4
post Feb 12 2020, 12:40 PM
Post #50


Member
**

Group: Members
Posts: 148
Joined: 26-May 19
From: England
Member No.: 23,161
Region Association: England



so I connected a jumper lead to the negative battery terminal and the engine and the starter sped up quite noticeably although not enough to fire up
I then ran a jump lead from the positive post on the starter to the positive to the battery, the starter remained at the increased speed but the engine didnt fire
suggesting a negative lead to battery problem
I also wonder about the non firing issue, could there be coil damage?
I swapped batteries over but to no effect and now have the better of the 2 on charge as it started to struggle.
I also tried the negative jumper on the starter itself to see if that was grounded, it ran at the improved speed but the doesnt sound to be any firing, I could take a plug out to see if there is a spark but I dont have a helper any more as the Mrs has fallen and broken her wrist
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
ctc911ctc
post Feb 12 2020, 03:10 PM
Post #51


Member
**

Group: Members
Posts: 364
Joined: 9-June 18
From: boston
Member No.: 22,206
Region Association: North East States



You should not have taken your frustration out on your darling bride! Seriously, I hope she will mend quickly.

(IMG:style_emoticons/default/biggrin.gif) (IMG:style_emoticons/default/biggrin.gif) (IMG:style_emoticons/default/poke.gif)

You need a 'lad' from the neighborhood to assist you - I would start by removing the grounding strap and cleaning and reattaching.

As to the firing (Carb or Injectors?) check on the spark first. The coil, points and perhaps other ignition parts can be damaged. Search web on "testing Ignition coil". This is pretty easy as to Good/Bad, however, some test OK and then do not perform properly.

However, to get going I would:

Check the plugs for firing
Check the plug wires
Inspect the cap and rotor (burn marks,etc)
Check the points (burn marks, etc.)

Hey, you got past one mystery, how many are left to go?


QUOTE(dt4 @ Feb 12 2020, 01:40 PM) *

so I connected a jumper lead to the negative battery terminal and the engine and the starter sped up quite noticeably although not enough to fire up
I then ran a jump lead from the positive post on the starter to the positive to the battery, the starter remained at the increased speed but the engine didnt fire
suggesting a negative lead to battery problem
I also wonder about the non firing issue, could there be coil damage?
I swapped batteries over but to no effect and now have the better of the 2 on charge as it started to struggle.
I also tried the negative jumper on the starter itself to see if that was grounded, it ran at the improved speed but the doesnt sound to be any firing, I could take a plug out to see if there is a spark but I dont have a helper any more as the Mrs has fallen and broken her wrist

User is offlineProfile CardPM
Go to the top of the page
+Quote Post
dt4
post Feb 12 2020, 03:23 PM
Post #52


Member
**

Group: Members
Posts: 148
Joined: 26-May 19
From: England
Member No.: 23,161
Region Association: England



thanks, the pointers are much appreciated
will report back (IMG:style_emoticons/default/clap56.gif)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
dt4
post Feb 13 2020, 12:21 PM
Post #53


Member
**

Group: Members
Posts: 148
Joined: 26-May 19
From: England
Member No.: 23,161
Region Association: England



IT RUNS !!!!!!!!!!!!

It took a lot of attempts but I got the feeling that it was trying to fire
just as it felt like the battery would die it fired and spluttered but with a bit of help on the throttle cable to lift the idle speed it started to run smoothly

It needed the jumper cable from the negative post to the engine and it wouldnt start if using the normal negative battery lead so I will order a new lead.

Its a relief to know nothing else is fried although none of the instruments are working so Ill have to check fuses etc....

thanks for all the input chaps (IMG:style_emoticons/default/thumb3d.gif)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Spoke
post Feb 13 2020, 04:00 PM
Post #54


Jerry
*****

Group: Members
Posts: 6,217
Joined: 29-October 04
From: Allentown, PA
Member No.: 3,031



Great news!

What about the alternator? Does it appear to be operating? Is the GEN light on or off? Does the GEN light come on when the key is turned w/o the engine running?
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
jcd914
post Feb 13 2020, 04:07 PM
Post #55


Senior Member
***

Group: Members
Posts: 1,923
Joined: 7-February 08
From: Sacramento, CA
Member No.: 8,684
Region Association: Northern California



QUOTE(Spoke @ Feb 13 2020, 02:00 PM) *

Great news!

What about the alternator? Does it appear to be operating? Is the GEN light on or off? Does the GEN light come on when the key is turned w/o the engine running?


He replaced the Alternator.


QUOTE(dt4 @ Feb 10 2020, 05:23 AM) *

so the latest...

I tracked an alternator down over here and fitted it at the weekend

With the ignition on I can hear the fuel pump running at the front, when I turn the key to start it is very slow to crank and is not firing, its as though the battery is virtually flat
I swapped out the battery for a spare that I believe to be good but the same result.

Looking for suggestions as to what else to check please

I am an electrical numbskull and whilst I have a circuit tester I have no clue how to use it.




User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Spoke
post Feb 13 2020, 05:11 PM
Post #56


Jerry
*****

Group: Members
Posts: 6,217
Joined: 29-October 04
From: Allentown, PA
Member No.: 3,031



QUOTE(jcd914 @ Feb 13 2020, 05:07 PM) *

He replaced the Alternator.


Thanks. Didn't read all the posts.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
dt4
post Feb 14 2020, 01:55 AM
Post #57


Member
**

Group: Members
Posts: 148
Joined: 26-May 19
From: England
Member No.: 23,161
Region Association: England



No warning lights but that said the instruments were all dead so more to look at there
The main thing was getting it running again after the mess up
I can now move it again when the weather improves and be able to clean down the garage in readiness for painting
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
ctc911ctc
post Feb 14 2020, 09:50 AM
Post #58


Member
**

Group: Members
Posts: 364
Joined: 9-June 18
From: boston
Member No.: 22,206
Region Association: North East States



Do not forget to remove, clean and reinstall the ground strap - many gremlins can hide in there.

Congrats on the start! You have finished your freshman class on 914 Electrics
(IMG:style_emoticons/default/cheer.gif) (IMG:style_emoticons/default/cheer.gif) (IMG:style_emoticons/default/beerchug.gif) (IMG:style_emoticons/default/beerchug.gif)

QUOTE(dt4 @ Feb 14 2020, 02:55 AM) *

No warning lights but that said the instruments were all dead so more to look at there
The main thing was getting it running again after the mess up
I can now move it again when the weather improves and be able to clean down the garage in readiness for painting

User is offlineProfile CardPM
Go to the top of the page
+Quote Post
dt4
post Feb 15 2020, 01:13 PM
Post #59


Member
**

Group: Members
Posts: 148
Joined: 26-May 19
From: England
Member No.: 23,161
Region Association: England



out of curiosity i tried the jumper lead from the battery negative to the connection bolt on the inner wing and there was clearly a poor connection as the starter struggled to turn over but it fired up pretty quickly once I earthed to the engine
The bolt and surrounding area on the inner wing are all nice and clean bright metal so thats puzzling
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
porschetub
post Feb 15 2020, 01:38 PM
Post #60


Advanced Member
****

Group: Members
Posts: 3,457
Joined: 25-July 15
From: New Zealand
Member No.: 18,995
Region Association: None



QUOTE(dt4 @ Feb 14 2020, 07:21 AM) *

IT RUNS !!!!!!!!!!!!

It took a lot of attempts but I got the feeling that it was trying to fire
just as it felt like the battery would die it fired and spluttered but with a bit of help on the throttle cable to lift the idle speed it started to run smoothly

It needed the jumper cable from the negative post to the engine and it wouldnt start if using the normal negative battery lead so I will order a new lead.

Its a relief to know nothing else is fried although none of the instruments are working so Ill have to check fuses etc....

thanks for all the input chaps (IMG:style_emoticons/default/thumb3d.gif)


Well done,pleased to hear you got it running (IMG:style_emoticons/default/beerchug.gif) .
User is offlineProfile CardPM
Go to the top of the page
+Quote Post

4 Pages V < 1 2 3 4 >
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: 27th February 2020 - 11:00 AM