Date: Wed, 6 Feb 2013 14:47:09 -0800
Reply-To: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Subject: Re: No Start Cause: Relay Failure. PICS, Thoughts.
In-Reply-To: <CAB2RwfiRBUFUXQsAfKtS1CvJhvxqzoOJuueM5U5p5zLLonakUA@mail.gmail.com>
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no kidding not using a relay socket is a bad idea.
puts stress on the pinsand relay ..
easy to mix up the wires ..
anytime I see a relay with individual wires stuck on it, I consider it a
pretty mickey mousemouse installationand not reliable.
Like Ilike to say in engine conversionwork ..'do what the manufacturers
do' ...and they use relay sockets only, to connect to relay pins.
lol ..'the worst' looking mickey mouse stuff I see is individual wires
on replay pins with some electrical tape ..
that always just falls off.
Shrinkable tubing and liquid electrical tape as needed is 5 times better.
vynyl tape is for wrapping wire bundles ....you'll find that on subaru
harnesses ...withthat split tubing ..
an noelectrical tape doing any actual insinsulating.
What is a 'wall wart" anyway .?
is that like worts on your wall or what ?
Every EFI system ECU I have ever seen energizes the fuel pump relay by
supplying ground to it. It's the common strategy.
On 2/6/2013 2:19 PM, neil n wrote:
> On Wed, Feb 6, 2013 at 1:00 PM, David Beierl <dbeierl@attglobal.net> wrote:
>> At 03:12 PM 2/6/2013, neil n wrote:
>> Well it certainly got hot enough to melt the solder around the terminal, but
>> that was from high resistance and arcing once the joint had already gone
>> bad.
> Understood.
>
> Since it's a yucky day outside, and I am suffering the remnants of an
> Electrical Victory celebration, took some more pics of the relay.
>
> Speaking of heat:
>
> https://lh6.googleusercontent.com/-vCPFjWDwWyw/URLRuT7232I/AAAAAAAAGzc/W6AxiYxxQgw/s640/109%2520relay%2520suppression%2520component.jpg
>
> 70º C temp at coil windings. Interesting to me that's all. Relay is
> powered from a "12 VDC" wall wart. Voltage may be higher.
>
>>> The replacement 109 relay is a different design;
>
>> VW relays with PCBs have a pair of molded-in rails inside the cover, that
>> the board slides into to support it against overall distortion/vibration.
>> Failing to mount the cover in this orientation will contribute to terminal
>> failures.
> Right. Yes. The old failing relay assembles as such. New one does not.
> (No PCB on it). It's seeming more and more obvious to me that not
> using a relay socket was a really bad idea.
>
>
>
>> ..... This particular relay is operated by switching the ground
>> lead rather than the hot lead of the coil. All this suggests to me that
>> it's being driven by an ECU output, is this correct?
> Yes. Order of events AFAIK: key to ign. on 15 + --> ECU. Energized
> ECU then sends - to power supply relay (109 relay). 109 relay sends
> + to main + buss in harness for fuel injectors, ECU, etc.
> Slightly annotated diagram image:
>
> https://lh3.googleusercontent.com/-8GS0_Zk_uJE/UQRc-4jPHLI/AAAAAAAAGtA/jibwhoITrAU/s800/power%2520supply%2520relay.jpg
>
>
>
>>> .... Both the Jetta
>>> Power Supply and Fuel Pump relays have a suppression component
>>> (appears to be a resistor) in parallel on 85 and 86 so I would make
>>> sure a substitute relay has same.
>>
>> Ok, how specifically does it appear to be a resistor? What does it look
>> like, exactly? Any numbers, banded end, color bands, body material, body
>> color, body shape? I guess a parallel resistor could be used to mitigate a
>> voltage spike, I'm just not accustomed to the idea.
> I may be wrong. Image of suppression component:
>
> https://lh6.googleusercontent.com/-vCPFjWDwWyw/URLRuT7232I/AAAAAAAAGzc/W6AxiYxxQgw/s640/109%2520relay%2520suppression%2520component.jpg
>
> At first glance looked like a resistor, but maybe not enough bands?
>
> And for fun, a close up of the relay switch. Not that revealing, but
> to my eye, part under magnifying lens, the contacts don't look too
> bad.
>
> https://lh4.googleusercontent.com/-vrLtjwmz4xI/URLRueP8Q9I/AAAAAAAAGzg/Jh2bqF0A6jE/s720/109%2520relay%2520contact%2520close%2520up.jpg
>
> Not sure if VW wanted to save money on wire, and in the process make
> sure owners would have to purchase a "special" relays, but the 109 is
> obviously wired from 30 to one side of the coil, so only 3 external
> connections required. The fuel pump relay is similar. Diagram image:
> (ignore my annotations):
>
> https://lh5.googleusercontent.com/-qjVqWgmKgiA/UQLzz0KnCHI/AAAAAAAAGq8/dV79PgDqWQg/s720/ABA%2520swap%2520coil%2520wire%253F.jpg
>
> I wired in an external jumper lead from 30 to 86 of relay. It has worked fine.
>
> Neil.
>
>
>
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