Starter turns when jumped 30 and 87a

[Lundegaard]

I'm about to test WUR and jumped 30 and 87a with a switch to turn on the fuelpump, but the starter also started to turn, so i switched off immediately again.
Is it the relay or something connectet wrong?

[pete3799]

You sure you're jumping the fuel pump relay?
What year car?

[boyt911sc]

Originally Posted by Lundegaard

I'm about to test WUR and jumped 30 and 87a with a switch to turn on the fuelpump, but the starter also started to turn, so i switched off immediately again.
Is it the relay or something connectet wrong?

Lundegaard,

Do yourself a favor by taking time reading the posts of DKLever48. Everything you need to know and understand about the FP relay and socket tests are discussed in his posts. This will help you able to ask your next question. Don’t feel bad because we all started from scratch and gradually developed the knowledge over time. Keep us posted.

Tony

[tirwin]

Originally Posted by Lundegaard

I'm about to test WUR and jumped 30 and 87a with a switch to turn on the fuelpump, but the starter also started to turn, so i switched off immediately again.
Is it the relay or something connectet wrong?

It’s hard to imagine how the starter would be actuated by jumping the FP relay. To amswer your question, something would have to be wired really wrong if the starter was indeed engaged by jumping those pins. Sometimes people do really strange things in attempting to fix cars though. If the starter was engaged by jumping those pins it would mean the starter was continuously running while the car was running, so that seems unlikely.

The fuel pump is a low humming sound.

[ossiblue]

Agree with all the above posts. You may have jumped 87a (switched power) with 87, which is the connection to the starter circuit. Your post indicates you were rigging up a switch between the two sockets. What was the wiring schematic for that switch? A simple wire from socket 87a to a single pole switch with the other lead in socket 30 would be all you needed.

[Lundegaard]

I have done the test discribed in post DKlever48 and have come to that i dont have ground on 85 when ignition is turned on?

[Lundegaard]

Forgot to mention it is a 1980 sc with lamba��

[Bob Kontak]

Originally Posted by tirwin

It’s hard to imagine how the starter would be actuated by jumping the FP relay.

Before I understood you jumper the relay socket holes and not the pins on the relay this happened to me.

[Lundegaard]

Just to be clear, i jumped 30 and 87a while the relay is still in the socket, a wire is turned around the 30 and the 87a with i switch between, and the relay mountet in the socket?

[Bob Kontak]

Originally Posted by Lundegaard

Just to be clear, i jumped 30 and 87a while the relay is still in the socket, a wire is turned around the 30 and the 87a with i switch between, and the relay mountet in the socket?

Put the wires between the holes - put the relay on the work bench.

[Lundegaard]

[Bob Kontak]

Exactly what I did.

It's confusing only because people talk about "jumpering the relay". You jump the sockets without relay installed.

[Lundegaard]

No i only jumped it with the relay on, but the starter also turns?

[Bob Kontak]

Originally Posted by Lundegaard

No i only jumped it with the relay on, but the starter also turns?

That is incorrect.

Remove the relay from the car to perform this test. It will turn the starter the way you are doing it.

Put the wires in the relay sockets/holes to perform the test.

[Lundegaard]

I now that that 85 is connectet to the airflow switch. I tryed with ignition on to lift airflow plate only 1-2 sek and i could hear something starting. But why cant i start the fuel pump without also starting the starter?

[Lundegaard]

Just tryed that and now it is workin, the fuel pump starts. Thanks

[tirwin]

Maybe this will help.

This is my setup for running the FP. It’s a switch and in-line fuse with bullet-nose connectors on the end.



Here’s a close-up of the ends crimped on with a little shrink tube.



When you wire it as you have with the relay in place, you will get a ground on pin 85 because the air pressure plate is closed. When the engine is started the pressure plate opens, which breaks the ground to pin 85 and then the FP relay provides power to pin 30 via 87a. As long as the there is a ground on pin 85, the FP relay DOES NOT provide power to pin 30. When you’re trying to do this test, you’re not starting the engine so the ground doesn’t get broken.

As Bob said, leave the relay on the bench. That removes the ground so you can run the FP.

Edit: looks like you were successful while I was writing this.

[Bob Kontak]

Good job.

[boyt911sc]

Originally Posted by tirwin

Maybe this will help.

This is my setup for running the FP. It’s a switch and in-line fuse with bullet-nose connectors on the end.



Here’s a close-up of the ends crimped on with a little shrink tube.



When you wire it as you have with the relay in place, you will get a ground on pin 85 because the air pressure plate is closed. When the engine is started the pressure plate opens, which breaks the ground to pin 85 and then the FP relay provides power to pin 87a. As long as the there is a ground on pin 85, the FP relay DOES NOT provide power to pin 87a. When you’re trying to do this test, you’re not starting the engine so the ground doesn’t get broken.

As Bob said, leave the relay on the bench. That removes the ground so you can run the FP.

Edit: looks like you were successful while I was writing this.

Tim,

Your understanding about how the FP relay works is FLAWED specially with terminal #87a. I strongly suggest to read DKLever48’s posts before we start the discussion.

Tony

[boyt911sc]

Originally Posted by Lundegaard

I'm about to test WUR and jumped 30 and 87a with a switch to turn on the fuelpump, but the starter also started to turn, so i switched off immediately again.
Is it the relay or something connectet wrong?

Lundegaard,

These are how the FP relay pins work with the ignition switch off.

NC (normally closed): 87a - 30
NO (normally open): 87 - 30

When you turned the ignition switch to ON position not START:

The NC (87a-30) terminals will open and the NO (87-30) will close because terminals 87a & 86 will have power provided that the relay is good and working plus the presence of ground @ terminal 85.

With the FP relay installed, bridging terminals 87a-30 like you did will cause the STARTER to run!!!!! It should be done with the relay removed. My good friend Bob K. made similar blunder years ago. So you are not alone.

Tony