• From: B.C.Canada
  • Registered: 2005-01-26
  • Posts: 2,585

Topic: hard start prevention with diode?

Has anyone ever heard of putting a diode from the solenoid wire to ground to save the ignition switch?

I just read that one thing that fry's ignition switches is a feedback pulse of electricity that comes from coils (solenoid) when they discharge. It causes a spark across the ignition terminals. Is that what the condenser prevents in the ignition coil?

So the article said if you put this certain diode from the starter wire to ground it will discharge this pulse. Has anyone done this or heard of it?

I've just started using diodes in a couple of projects and I seem to get them in backwards every time, even though by the law of averages I should get it right half the time. Electricity flows from - to + right? It did when I studied electricity, but they were still using tubes then and it was just a theory.

jim

'71 SB(DD only 79K(now 84K miles) & '78 FI Westy (project)
PO of '65 Beetle in '69, '70 Crewcab & '70 Ghia in '77
'71 Super inside rear vents now available
http://www.openroad.ca/volkswebbin/view … p?id=85915
  • From: Cincinnati, Ohio
  • Registered: 2005-09-10
  • Posts: 2,318

Re: hard start prevention with diode?

I've honestly never heard of anyone frying an ignition switch (assuming someone didn't wire things incorrectly, and assuming we are not talking about a high performance application). 

I'm sure it can & does happen...just never heard of anyone having this problem.  So I would think that jumping off the couch & installing a diode ASAP is not necessary.

Just my humble opinion,

- Nick

p.s.  Now after saying that...my ignition switch will fry the next time I start the Beetle!  ; )

Last edited by Bug In My Nose (2009-02-22 15:50:46)

1979 Super Beetle Convertible
  • From: B.C.Canada
  • Registered: 2005-01-26
  • Posts: 2,585

Re: hard start prevention with diode?

Not frying, just prematurely wearing. They said with the diode you would not need a hard start relay in the future. New cars all have them. I was just curious.

jim

'71 SB(DD only 79K(now 84K miles) & '78 FI Westy (project)
PO of '65 Beetle in '69, '70 Crewcab & '70 Ghia in '77
'71 Super inside rear vents now available
http://www.openroad.ca/volkswebbin/view … p?id=85915
  • Registered: 2007-03-27
  • Posts: 2,422

Re: hard start prevention with diode?

Yeah Jimm you need one !
  Consider 7.5 -1 CCR on a Stock 1600cc ?? Now consider that Engine rebuilt at 8.5-1 or 9-1 CCR ?? Or consider a 1776cc or 1835cc at 9-1 CCR ????
  Just goes to reason that you need more cranking ability !
  In the Old Day's we used Ford Starter Solenoid's ! You probably have Jumped the Ford Solenoid that is usually Mounted on the Fender Well next to the Battery in Old Ford's with a screw Driver to Turn Old Ford motor's over ?
   But Now a Day's Aftermarket companie's have realized the need to by pass the key switch and 10 Ft of wire that runn's from the Key switch back to the starter solenoid by selling you a Starter Relay, manufactured specifically for this !
   This shortens the 10 ft of wire from the switch to about a Foot straight off the battery !
  There 20 buck's and 20 Minute's to install ??? Ive written extensively on these several time's in here ?
  Guess I know who is really, not readin my Post ? LMAO
  INdication  that you warrant a starter relay ( I Do it to all of them ) But If you turn key swich and Nothin ! Then jump the starter solenoid with screw driver and it turn's the motor over ?
  Then the Key switch start's workin again ? Just to quit workin a week later or Month Later !
  Definately need to install a Starter Relay !! Like I said I dont wait to have a Problem ! I just install them if there isnt one !
  Starter Solenoid's will last Longer etc. etc.
                                                          Sean

  • Registered: 2007-03-27
  • Posts: 2,422

Re: hard start prevention with diode?

P.S. I read the post again ! This time I Paid attention to the Drivel !!!
  What happen's with point's is it Pitt's them on start up because of the Drain and Pull of the Starter on start up !
  Ive heard of what your talkin about ? But with Electronic ignition's availiable and a Hard start Relay installed and Clean Batt Cable's and a carefull Timming procedure not really neccessary ??
  But Your point's would last a Lott longer if a Diode like your talkin was installed !!
                    Sean

  • From: Cincinnati, Ohio
  • Registered: 2005-09-10
  • Posts: 2,318

Re: hard start prevention with diode?

jamesdagg wrote:

Not frying, just prematurely wearing. They said with the diode you would not need a hard start relay in the future. New cars all have them. I was just curious.

jim

Thanks for clarifying that Jim!  I thought you meant that at any given time when starting the car that the ignition switch could "fry"...of course premature wear is no fun either.

- Nick

1979 Super Beetle Convertible
  • From: B.C.Canada
  • Registered: 2005-01-26
  • Posts: 2,585

Re: hard start prevention with diode?

I was just curious about the use of diodes to save electrical equipment wear. There are one of the first electronics put in a Beetle. There is one in the later style brake warning light. They needed it otherwise when you push for the bulb test the brake lights would come on as well.

Some of us listen to you Sean!

I already installed a hard start relay well before I have ignition problems. I think it's GM.

http://i43.tinypic.com/2e1c9wy.jpg

jim

Last edited by jamesdagg (2009-02-23 23:22:16)

'71 SB(DD only 79K(now 84K miles) & '78 FI Westy (project)
PO of '65 Beetle in '69, '70 Crewcab & '70 Ghia in '77
'71 Super inside rear vents now available
http://www.openroad.ca/volkswebbin/view … p?id=85915
  • Registered: 2007-03-27
  • Posts: 2,422

Re: hard start prevention with diode?

Hey Jim if you like electronic's figure out how to fix the Wind Sheild wiper problem !!
  Deal is if you pull your ride in in the rain with wind sheild wiper's runnin and turn the Key off, with out turnin the wiper switch off first before turnin the Key off ?
  Will drain the battery if you lett it sit !
  As to preserveing the Key switch ?? I hate the Brazillian replacement's ! The tumbler doesnt work the Plastic switch on the Ignition right and Blow's the spring in the Plastic switch !
                                                          Sean

  • From: Bethel Park PA
  • Registered: 2004-06-27
  • Posts: 686

Re: hard start prevention with diode?

jamesdagg wrote:

I was just curious about the use of diodes to save electrical equipment wear. There are one of the first electronics put in a Beetle. There is one in the later style brake warning light. They needed it otherwise when you push for the bulb test the brake lights would come on as well.

Some of us listen to you Sean!

I already installed a hard start relay well before I have ignition problems. I think it's GM.

http://i43.tinypic.com/2e1c9wy.jpg

jim

Mine has a shorter run than yours...
http://www.geocities.com/dyouse2000/VWphotos/042.jpg

David H
'66 VW Beetle w/sunroof
http://tinyurl.com/qhw59
"Where am I going ... and why am I in this handbasket?"
  • From: B.C.Canada
  • Registered: 2005-01-26
  • Posts: 2,585

Re: hard start prevention with diode?

David H wrote:
jamesdagg wrote:

I was just curious about the use of diodes to save electrical equipment wear. There are one of the first electronics put in a Beetle. There is one in the later style brake warning light. They needed it otherwise when you push for the bulb test the brake lights would come on as well.

Some of us listen to you Sean!

I already installed a hard start relay well before I have ignition problems. I think it's GM.

http://i43.tinypic.com/2e1c9wy.jpg

jim

Mine has a shorter run than yours...
http://www.geocities.com/dyouse2000/VWphotos/042.jpg

PERFECTIONIST!!

I'm too lazy for that but yeah that's the best by far. Nice clean looking install.

Where did you get that split boot?

jim

Last edited by jamesdagg (2009-02-24 21:46:39)

'71 SB(DD only 79K(now 84K miles) & '78 FI Westy (project)
PO of '65 Beetle in '69, '70 Crewcab & '70 Ghia in '77
'71 Super inside rear vents now available
http://www.openroad.ca/volkswebbin/view … p?id=85915
  • Registered: 2007-03-27
  • Posts: 2,422

Re: hard start prevention with diode?

Yeah Im not sure I like it mounted on the boot ?? But then that's what V.w.'s about ??
  Figurin out a better mouse trapp !!
                                        Sean