FE-FC Holden Discussion Forum

Technical Board => General Technical => Topic started by: MechanicalMal on November 10, 2005, 01:19:02 PM



Title: Stray current
Post by: MechanicalMal on November 10, 2005, 01:19:02 PM
 Guys,
I am Mechanical Mal.
I have read your 'not so informed' comments about this distructive and costly radiator disease 'Stray current'.
You have tickled my funny spot with your coments about fruit.
This is the only funny thing about SC.
I will indulge you by giving you the good info on stray current (SC).
You never know, it may save your radiator.
here goes.
Stray currents in the cooling system
In simple terms stray current is a chemical/electrical process which causes an electrical current to pass through a vehicles cooling system fluid.
It can cause rapid damage to radiators and will indirectly cause problems with other engine components such as water pumps, thermostat housings, etc.
This is brought about when one or more items such as a cooling fan or headlamp develops a problem in its electrical circuitry.
This causes an electrical current to seek out an earth path via the radiator core through the engine coolant.
The most common fault is the body/battery earth lead being loose, dirty or not in place.
That is what it is , now for the test prodecure.
The procedure employed to test for Stray Current is:
1. Remove the radiator cap and run the engine to operating temperature at idle speed.

2. Switch ON all electrical circuits including items such as a fan, rear demister, head lights, radio, wipers etc.

3. Attach an ANALOGUE multi meter. Set meter to volts. Use as low a scale as you can.

4. Connect the negative lead of the meter to the battery negative post.

5. Dip the positive lead into the coolant without touching the filler neck.

6. Test the coolant – if the READING above 0.5V, there is stray current present. 0V is best.

7. If no reading, there is no StrayCurrent was present. to continue if stray current is present;

8. Systematically, the electrical system is tested by turning electrical circuits OFF individually and testing the meter prior to turning off the next circuit.

9. After all circuits were turned off, and stray current is still present. continue.

10. At this stage a temporary earth lead can placed between the battery negative post and the body.

11. Immediately the circuit should test free of stray current.

12. Remove the temporary earth lead and stray current will be noted noted in the cooling system.

13. The battery to body earth cable is to be inspected.

14. If necessary, make up a new lead out of 6mm cable and secure it from the battery neg post to the body or radiator itself. Make sure you remove paint from the body to ensure a good contact.

15. Retest and there should be no SC.

Remember, SC is instant death to aluminium radiators and brass alike. Aluminium will corrode 253 times faser than brass.
Note, brass does not transmit heat as well as Aluminium.
never mix coolant types.
always flush with good clean water prior to adding good quality additives.

Best of luck.
MM


Title: Re: Stray current
Post by: Glenn 'Stinky' Stankevicius on November 10, 2005, 01:50:12 PM
G'day Mal, welcome to the forum (I think?).
2 things

1. Are you in the right place? not sure I have seen a post about stray current recently.

2. Although your post is informative and probably helpful to some, you'd better lighten up on the language. Cocky comments such as yours aren't really welcome around here.


Title: Re: Stray current
Post by: Sarge on November 10, 2005, 07:39:40 PM
Yeah well what can I say,  but are thanks for the lesson Mal  ??? ???

Cheers
Sarge


Title: Re: Stray current
Post by: nicko on November 10, 2005, 09:12:24 PM
thanks for the lesson Mal,
i found it extremely interesting but also cant remember anyone asking about it,still i found the old adage (you learn something new everyday )came true again.
very informative,thanks
Nicko


Title: Re: Stray current
Post by: craiga on November 10, 2005, 10:02:16 PM
Try here http://www.fefcholden.org.au/cgi-bin/yabb/YaBB.cgi?board=howto;action=display;num=1044226644;start=14

Was discussed about 2 years ago.


Title: Re: Stray current
Post by: Glenn 'Stinky' Stankevicius on November 10, 2005, 11:14:09 PM
Thanks CraigA, that makes more sense now, I only searched back 2 months  ::)
I gave it a bump too.

Thanks Mal, sorry for the confusion, technically you should have replied to the original topic to save all the confusion.


Title: Re: Stray current
Post by: MechanicalMal on November 11, 2005, 01:28:19 AM
Gents,
Thanks for your replies.
I found this site inadvertantly by doing a web search on instances of Stray Current (SC) and was having a good chuckle when reading the comments and replies to some of the other subjects. I am glad the Oz sence of humour continues.
Its good to be able to have a smile while getting into it.

For some background info, I started life restoring an FX in 1970 and moved onto my first J in 73.
Then it was up hill with an FE,  what a beast. great car to drive.

Anyway, I was in a state of nostalgia when seeing all your good work on your machines I decided to contribute my article and hopefully save you fellas from expensive and unnecessary cooling system costs.

apologies for a perceived cocky remark. not the intent at all.

I am now learning the site rules and hopefully can add some worthwhile info again.

feel free to ask this old auto engineer for techo assistance. I would be glad to put my ten cents worth in.

Keep up the good work.

Cheers
MM


Title: Re: Stray current
Post by: Grah on November 11, 2005, 01:50:15 AM
Is the term stray currents a bit of a misnomer? Should it not be difference in potetial between two or three materials / metals that allows electrochemical action especially when presented with or immersed in an electrolyte (liquid)? Currents measured are usually milli amps and although extremely distructive its the difference in potential across the two materials that causes the problem. Ohms Law V = IR.
I am digging this out of a very old, addled and tiered brain and may have completely lost the plot, engineers altz being a problem. Perhaps a dose of current is the cure??


Title: Re: Stray current
Post by: MechanicalMal on November 11, 2005, 02:28:05 AM
Hi Grah,
Thanks for the reply.
I am glad your 'old' brain is on the ball.

The term 'Stray Current ' is a real term and a nasty bit of work.

I wish the problem could be linked to dissimilar metals but unfortunately it is more like insulated metals with an electrical system searching out an earth.
The coolant is the vehicle that the current uses in its search to get back to the battery.

Plastic tanks with a radiator core of aluminium or brass makes the core the victim.

Don't forget the heater core. Out of sight is definitely not out of mind. A heater core that fails in a restored car is expensive and the collateral damage is immense.

My best advice is remove your earth leads, don't just look at them, rub the terminals with emery so they sparkle and refit with CRC or a protection medium to inhibate the formation of corrosion. Check the body to engine earth lead as well.

My FC had one on the gearbox mount. Make sure it is in excellent condition.

Fresh water and good quality additives and there you go.

I hope this assists you and has answered your question.

(PS , if any one runs LPG, make sure the upper most point of the converter is installed lower than the top of the radiator and is well earthed)

Cheers

MM


Title: Re: Stray current
Post by: Grah on November 11, 2005, 02:49:19 AM
Thanks Mal,

Good advice about the heater core!

I use good old Vasalene, or Vick - smells nicer,lol - on all my battery and earth connections, seems to work, stops the build up of "crud".


Title: Re: Stray current
Post by: knickers on November 11, 2005, 09:34:33 AM
Stinky I think it's you who should lighten up !! and I ask

Who is welcome on this site?
What comments are welcome?

Because of the pathetic bickering a very few thin skinned members we will no longer visit this site.
Thanks fellow members for the information I have gathered on this site & good luck with you projects.


Title: Re: Stray current
Post by: Glenn 'Stinky' Stankevicius on November 11, 2005, 01:51:12 PM
Oh dear!
OK, I will try to justify my post, even though I feel I shouldn't have to.

I have been given the role of moderator on some of the forum's boards. I see this as a duty to ensure the smooth and safe running of such boards. This task also includes keeping members in-line, helping out and guidance. I would rather nip something in the bud than let it turn into a shtit storm.

The facts as I see them -
1. Mal seemed to come out firing with an accusation of members being ill-informed.
2. I researched a little and found no reference to Stray Current recently and posted my reply.
3. CraigA researched a little more thoroughly then me and found the original post which put everything into context.
4. I APOLOGISED! rather than delete my original post and make the whole thread look weird.

I don't expect to make any friends when I put the mod cap on, but I would rather that than see the Forum be degraded.

If you choose to leave because of these actions, then so be it.


Title: Re: Stray current
Post by: oldgmh on November 12, 2005, 12:26:54 AM
Its okay stinky  ;D

You don't need forgiveness  for just doing your job. :-[
You probably need more appreciation!   :) :)

someone has to devote the time and energy, which a lot of us won't do, so thank you very much for doing so.

regards
earlee


Title: Re: Stray current
Post by: Al on November 12, 2005, 04:48:14 AM
Thank you Mal,how you explained about Sc was excellent. After reading that I bet there would have been a lot of guys going out to there cars and checking the earth leads. Thats what this Forum is about which is helping each other out. Hey Mal don,t go anywere, stick around we need more guys like you on this Forum. Again thank you Mal.

   Cheers Al


Title: Re: Stray current
Post by: ACE on November 12, 2005, 08:20:53 AM
Hey MM,
I checked my FC for SC and it's O.K. ;)
Regards ACE  8)


Title: Re: Stray current
Post by: MechanicalMal on November 14, 2005, 09:39:56 AM
 :)
Gents,
I sincerley hope I did not set the dogs barking.
Every site should have a moderator.
but the moderator should be ' moderate' and not so 'impetuous'

Seems I made a remark in reply to the funny comments some of the guys made in reference to currents (the fruit)
Mr. Moderator jumped right in and - oh well, here we are.

Never the less, my aim to help those that appreciate knowledge seems to have been achieved.

Lets all smile and learn a little technology.

From the replies, many of you have benefited and I am very happy.

I am happy to enlighten you guys on any other interesting or troublesome mechanical issues.
(how about LED tail lights)

Cheers for now and keep up the good work.

MM


Title: Re: Stray current
Post by: 4hammers on November 14, 2005, 09:46:35 AM
Hi Mal.
All good now, I think.
Thanks for the info on "Stray Currents" issue. I don't think I have ever had this problem, but I jumped at the chance of being able to post my "Currant Bun" joke on the forum. You know how often you get to use a joke like that? Not much at all.............some say thankfully.
Looking forward to hearing more & if you need anymore bakery jokes, I am the man to see ;D ;) ;)

Rob J


Title: Re: Stray current
Post by: MechanicalMal on November 14, 2005, 10:13:34 AM
Hey Rob,

I was truely impressed with the current bun joke.
Heard it numerous times but you have put the edge to it.

Cheers and thanks for the input.

MM


Title: Re: Stray current
Post by: RET on November 14, 2005, 11:18:04 PM
Mechanical Mal,

(By way of introduction I am the Administrator of this site, and as such the "Chief" Moderator.  We haven't met or spoken before, so welcome to the FE-FC Forum.)

I've stayed out of this so far, and have no problem with the way Stinky has looked after it.

However, (in response to this thread being "Reported" several times since it started), a couple of comments.  Perhaps if you had replied to the original topic rather than starting a new one there wouldn't have been the confusion about what you were on about with the 'not so informed' comments and the like.  That got things off to a less-than-ideal start.

Secondly, maybe you could lay off the 'not so informed' and 'I am about to enlighten you guys' remarks.  Your knowledge and input is appreciated, but there's no need to lecture the rest of us like school-kids.  Have a look around, there's a lot of knowledgeable people on this forum.  You don't see other members couching their replies in this air of superiority.  I don't know you personally, so as a stranger it reads like this bloke MM has a few tickets on himself.

Let me repeat: we are grateful for the knowledge you're sharing.  I'm hopeful we can make a fresh start, and we welcome you to the FE-FC Forum.

cheers
RET