

| Subject: | Re: "yawn" Another (trivial) Jetta conversion Fuel Pump relay question.... ;^) |
| From: | Mike S |
| Date: | Sat, 19 Apr 2008 07:10:33 -0400 |
At 09:25 PM 4/18/2008, neil N wrote... >One thing I had to do, was run a jumper between 30 and 86 on FP relay. >In Bentley, it shows an internal connection doing the same (though >there's no "86" shown): > >http://tubaneil.googlepages.com/FPrelaydiagram.jpg/FPrelaydiagram-full.jpg Because the Jetta relay doesn't have an "86" terminal. I doesn't have 4 contacts. It sounds like you're using a generic Bosch type relay (4 or 5 contacts, 2 for coil, 1 for relay arm, 1 or 2 for relay contacts). >My potentially trivial quesiton: > >In diagram on fuel pump relay, there is an icon between 85 and 86. I >looked inside and there was a resistor. > >Why is that resistor there? You'll have to provide an image, it's not shown (86) on either of the pictures you posted: http://tubaneil.googlepages.com/jettafinal1.jpg/jettafinal1-full;init:.jpg http://tubaneil.googlepages.com/FPrelaydiagram.jpg/FPrelaydiagram-full.jpg Maybe you're talking about the J17 relay on the second diagram??? Between 85 and 30 is the relay coil (electromagnet). The dashed horizontal between it and the relay contact arm indicates a mechanical linkage. Contacts are normally shown with the relay in the unenergized state, so for this relay, putting power between 85 and 30 would connect terminals 30 and 87. The resistor which you may find in parallel (across) the relay coil is a damping resistor (and is not shown in the diagram), it helps to reduce the voltage spikes caused when the relay is de-energized, and the stored magnetic field collapses (like happens with an ignition coil).
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