Starter Relays, I recommend them on all cars now |
|
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. |
|
Starter Relays, I recommend them on all cars now |
McMark |
Nov 10 2013, 03:16 PM
Post
#1
|
914 Freak! Group: Retired Admin Posts: 20,179 Joined: 13-March 03 From: Grand Rapids, MI Member No.: 419 Region Association: None |
I've been meaning to post this for awhile and Andyrew's recent starter thread inspired me. I used to recommend against a relay at the starter because it was always known as a 'hot start' relay, and hot start issues can be a sign of a wearing starter. So I considered the relay to be a baind-aid to avoid have to really fix the problem - a bad starter.
Jamie (JRust) was having some ignition switch issues and I started to rethink my position on the starter relay. I realized that the crappy reproduction ignition switches that are available now are prone to failure from having too much current pushed through them. They simply aren't built with enough focus on quality to stand up to the way Porsche/VW designed the starting system. So now I recommend a starter relay on all cars in order to avoid undue stress on either old, tired factory ignition switches or crappy reproduction switches. This can be any 30A or larger relay and Bosch sells a starer relay kit, but I didn't like some of the choices they made, especially because it's sold as a universal kit, which means it doesn't fit nicely on anything. So I put together my own kit designed specifically for our cars. I also found a relay that has a fuse built in, rather than a separate unit. A starter relay can be made with pieces available from your FLAPS, but for those of you who don't feel like going that route, I've made a few of my setup available for sale. This thread is more about sharing information though, so I'll exclude the details here. Attached image(s) |
Spoke |
Nov 10 2013, 03:39 PM
Post
#2
|
Jerry Group: Members Posts: 7,052 Joined: 29-October 04 From: Allentown, PA Member No.: 3,031 Region Association: None |
I like your re-fit. I want one. Looks very clean.
It is '70s technology to run the solenoid of the starter through the ignition switch. Powering an inductor like the solenoid is just bad for the switch. When turning off the solenoid, there is likely an arc across the ignition switch which can lead to premature failure. This isn't done at all today. Most motors, contactors, lighting, solenoids are likely controlled by relays or MOSFET or NPN solid state switches. Would you please explain what is in your kit and show a schematic of the circuit? I'm curious of the fuse shown in the pic. |
jvmarino |
Nov 10 2013, 04:16 PM
Post
#3
|
Member Group: Members Posts: 89 Joined: 22-March 09 From: Baltimore Member No.: 10,188 Region Association: None |
I added one to my car a few years back. I still have issues every now and then, but I believe it is due to poor electrical contact of the blade fuse, as fiddling with the fuse holder usually solves the problem when it does happen. It beats crawling under rear tire to jump the started solenoid with a screwdriver (especially if you are on a date (IMG:style_emoticons/default/smile.gif).
Your design looks nicely packaged, but one concern I would have with the installation location is the relay/fuse will be exposed to the elements (as well as the heat from the exhaust system). Mine is mounted on the rear wall of the engine compartment, and the fuse holder is a rubber capped unit. I am sure mounting it inside the trunk would be even better, I used my location for ease of wiring the retrofit, as well as easy fuse access. Jim |
Mike Bellis |
Nov 10 2013, 04:31 PM
Post
#4
|
Resident Electrician Group: Members Posts: 8,346 Joined: 22-June 09 From: Midlothian TX Member No.: 10,496 Region Association: None |
(IMG:style_emoticons/default/agree.gif)
100% All new cars have a starter relay. The ignition switch should never transfer that much current. Carbon builds up over time and will render the switch useless... |
jimkelly |
Nov 10 2013, 04:41 PM
Post
#5
|
Delaware USA Group: Members Posts: 4,969 Joined: 5-August 04 From: Delaware, USA Member No.: 2,460 Region Association: MidAtlantic Region |
after getting my v8 engine connected to fuel and what not, and running it a little bit in my garage, several times the starter and ring gear did not fully engage. I do not know if my switch is faulty or not. BUT I've been thinking full power (consistently) may not be making it thru and have been thinking about this very thing. thanks to mark for always giving full thought to 914 issues. jim
I stumbled upon these pics I saved to my computer Attached thumbnail(s) Attached image(s) |
shuie |
Nov 10 2013, 05:04 PM
Post
#6
|
Member Group: Members Posts: 352 Joined: 17-May 04 From: baton rouge, la Member No.: 2,075 |
Awesome. I have one in my cart to order. Why is it charging me CA sales tax in the shopping cart?
|
Mark Henry |
Nov 10 2013, 05:06 PM
Post
#7
|
that's what I do! Group: Members Posts: 20,065 Joined: 27-December 02 From: Port Hope, Ontario Member No.: 26 Region Association: Canada |
Been doing this for 25 years. (IMG:style_emoticons/default/smile.gif)
|
ConeDodger |
Nov 10 2013, 05:10 PM
Post
#8
|
Apex killer! Group: Members Posts: 23,758 Joined: 31-December 04 From: Tahoe Area Member No.: 3,380 Region Association: Northern California |
Yes please. (IMG:style_emoticons/default/biggrin.gif)
|
Mike Bellis |
Nov 10 2013, 05:27 PM
Post
#9
|
Resident Electrician Group: Members Posts: 8,346 Joined: 22-June 09 From: Midlothian TX Member No.: 10,496 Region Association: None |
|
r_towle |
Nov 10 2013, 05:38 PM
Post
#10
|
Custom Member Group: Members Posts: 24,624 Joined: 9-January 03 From: Taxachusetts Member No.: 124 Region Association: North East States |
Why a fuse?
|
Spoke |
Nov 10 2013, 06:17 PM
Post
#11
|
Jerry Group: Members Posts: 7,052 Joined: 29-October 04 From: Allentown, PA Member No.: 3,031 Region Association: None |
Why a fuse? I was wondering this too. The only thing I could think of is the red wire comes directly from the heavy starter wire from the battery. When active, the relay connects the yellow wire to the red wire (12V) with no fusing. The fuse must be to protect the relay and wiring from shorts. |
76-914 |
Nov 10 2013, 07:14 PM
Post
#12
|
Repeat Offender & Resident Subaru Antagonist Group: Members Posts: 13,611 Joined: 23-January 09 From: Temecula, CA Member No.: 9,964 Region Association: Southern California |
Exactly. Nice install. I went the Ford route. +1
|
Tom |
Nov 10 2013, 07:52 PM
Post
#13
|
Advanced Member Group: Members Posts: 2,139 Joined: 21-August 05 From: Port Orchard, WA 98367 Member No.: 4,626 Region Association: None |
Mark, you are right on with this modification! The contacts in the ignition switch are not designed to handle the arc from the initial closing contact or the arc produced by the break of contact in ignition switches. Relay contacts , however, are engineered to suppress the damage by the arcing so they last longer. The engineers at VM/Porsche did a good job with what they had at the time, but there are much better solutions available now. I already modified my electrical system years ago to take advantage of newer technology or I would be following your advise.
Tom |
jimkelly |
Nov 10 2013, 07:53 PM
Post
#14
|
Delaware USA Group: Members Posts: 4,969 Joined: 5-August 04 From: Delaware, USA Member No.: 2,460 Region Association: MidAtlantic Region |
I assume the high current circuit is grounded thru the starter.
how is the low current circuit grounded? is the another wire I am not seeing? jim |
Spoke |
Nov 10 2013, 08:10 PM
Post
#15
|
Jerry Group: Members Posts: 7,052 Joined: 29-October 04 From: Allentown, PA Member No.: 3,031 Region Association: None |
|
jimkelly |
Nov 10 2013, 08:25 PM
Post
#16
|
Delaware USA Group: Members Posts: 4,969 Joined: 5-August 04 From: Delaware, USA Member No.: 2,460 Region Association: MidAtlantic Region |
I do see a small wire loop underneath but can't see where it comes from or goes, but this must be it?
|
Elliot Cannon |
Nov 10 2013, 08:58 PM
Post
#17
|
914 Guru Group: Retired Members Posts: 8,487 Joined: 29-December 06 From: Paso Robles Ca. (Central coast) Member No.: 7,407 Region Association: None |
So, where to I hook up the big assed wire that comes from my battery? I want one of these but it better come with instructions. (IMG:style_emoticons/default/laugh.gif)
|
jimkelly |
Nov 10 2013, 09:38 PM
Post
#18
|
Delaware USA Group: Members Posts: 4,969 Joined: 5-August 04 From: Delaware, USA Member No.: 2,460 Region Association: MidAtlantic Region |
I think the big assed wire from battery goes to same stud on starter as the red wire pictured above, thus it is where the red wire pictured above gets its power from.
|
Mark Henry |
Nov 10 2013, 09:47 PM
Post
#19
|
that's what I do! Group: Members Posts: 20,065 Joined: 27-December 02 From: Port Hope, Ontario Member No.: 26 Region Association: Canada |
|
jim_hoyland |
Nov 10 2013, 09:58 PM
Post
#20
|
Get that VIN ? Group: Members Posts: 9,418 Joined: 1-May 03 From: Sunset Beach, CA Member No.: 643 Region Association: Southern California |
Is that a 3 PIN relay ? Is the clamp The ground ?
|
Lo-Fi Version | Time is now: 27th September 2024 - 06:43 AM |
All rights reserved 914World.com © since 2002 |
914World.com is the fastest growing online 914 community! We have it all, classifieds, events, forums, vendors, parts, autocross, racing, technical articles, events calendar, newsletter, restoration, gallery, archives, history and more for your Porsche 914 ... |