Date: Tue, 5 Feb 2013 23:44:01 -0800
Reply-To: Dick Wong <sailingfc@DSLEXTREME.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dick Wong <sailingfc@DSLEXTREME.COM>
Subject: Re: No Start Cause: Relay Failure. PICS, Thoughts.
In-Reply-To: <CAB2RwfjO6aDKaodFewkYPuZXyn_ViGRK_amo6w3JvmFOL5oVbA@mail.gmail.com>
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Neil,
From the looks of the solder joint, the "extra" flux (brown stuff) that is
visible around the solder pad indicates that someone was in there soldering
that very joint before. So someone else had the same problem. The crack
looks to be jagged with some wrinkles on the surface of the solder around
the break (nice pictures). To me this means the joint cracked due to
mechanical stress and heat. The mechanical stress may have been from
vibration. Check the contacts of the relay too. If the contacts are pitted
and dull there probably is a lot of resistance and that causes high heat.
With my old Scirocco, the fuel pump relay will get hot to the touch and has
actually melted the side of the plastic case. After filing and cleaning the
contact, it typically runs cooler. I also keep a spare fuel pump relay.
-Dick Wong-
78 Scirocco
Original Owner
87 Syncro 2.5 (slightly crispy)
Third Owner
12 Golf TDI
Original Co-Owner
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
neil n
Sent: Tuesday, February 05, 2013 10:43 PM
To: vanagon@GERRY.VANAGON.COM
Subject: No Start Cause: Relay Failure. PICS, Thoughts.
Hi all.
This isn't for a stock Vanagon, but I figure it's worth mentioning here.
(it's Jetta engine powered)
After doing a bunch of work on my van, it wouldn't start. I'd had rare
random no starts not long after the swap was finished and had one mysterious
highway speed stall. Until today, I could not figure out why the most likely
cause of them was.
With my engine, the fuel pump and ECU relay are mounted "loose"
(actually they're packed pretty tight in a Vanagon junction box); they're
not mounted in relay blocks. While trouble shooting this no start, with key
turned to ign. on I heard a relay buzzing intermittently. Since this relay
was mounted "loose", I could wiggle each relay wire til I found the culprit:
a cracked solder joint at the
30 pin of my power relay. (supplies power to fuel injectors, ECU,
etc.)
Close up images of the cracked solder joint:
https://lh4.googleusercontent.com/-h3JODsFUDHM/URHsPfqBbZI/AAAAAAAAGy4/5DkyK
weHpnc/s576/Jetta%2520Power%2520Supply%2520Relay%2520Solder%2520Crack.jpg
https://lh3.googleusercontent.com/-vmq-vUhQT4s/URHsPue73gI/AAAAAAAAGzA/cNsoA
Ux6cJw/s640/Jetta%2520Power%2520Supply%2520Relay%2520Solder%2520Crack%25202.
jpg
I don't know if any WBX or air cooled engines have relays with printed
circuit boards, but if they do...
When diagnosing a no start, if one pulled a relay part way out of it's
socket, then gently pushed-pulled on it, would this help determine if
there's a physical fault at a relay?
Maybe this technique (or similar) has been written of here already?
Neil.
--
Neil n
65 kb image Myford Ready For Assembly http://tinyurl.com/64sx4rp
'88 Slate Blue Westy to be named.
'81 VanaJetta 2.0 "Jaco" http://tubaneil.googlepages.com/
Vanagon VAG Gas I4/VR Swap Google Group:
http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engine
s
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