Relay Information Please

Post Thu Aug 15, 2024 10:46 pm

Hi everyone

I have a 7 pin relay from a 1985 320i Bmw and I cannot identify some of the pin numbers and I cannot find a reference for it in the Paynes manual!!

I Know that Pins 30 & 87 are the load side.
But I also have a Pin 15, Pin 31, Pin 50, Pin 87b and Pin TD

Now I think Pins 31 and 87b is another switch point but as for Pins 15,50 and TD I am not too sure about.

I have added photos to help show their positions on the relay and I have tried testing for continuity/ohms across the following Pins
15 to 50 multimeter shows OL
15 to TD Multimeter shows OL
50 to TD Multimeter shows OL
15 to 31 Multimeter shows OL
15 to 87b Multimeter shows OL
31 to 87b Multimeter shows OL

I have also checked Pins 30 to 87 and Multimeter shows OL as it should.
And when the relay is plugged into the car I can hear the relay pull in.

I would like to replicate this on a Bench Test but I don't want to damage the relay by connecting it up incorrectly to a power source even though it probably is broken.

I know that the TD Pin doesn't stand for Turbo Diesel lol and I have just fitted new batteries into my multimeter and tested it on other relays and its working fine but I would welcome any help or advice on this.

Also any advice on where I could buy a replacement.

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Post Tue Aug 20, 2024 6:36 pm

Are there any auto electricians on here who might know?

Post Tue Aug 20, 2024 8:49 pm

OK I have dug out my notes

TD = time delay (usually a pulse from negative side of coil)
50 Live when starting
30 Hot Live
15 Live with ignition (switched live)
31 Earth
87 Live when relay is on
87a Live when relay is off (changeover)
87b Second live like 87

HTH

Post Thu Aug 22, 2024 11:29 pm

flybynite wrote: ↑
Tue Aug 20, 2024 8:49 pm
OK I have dug out my notes

TD = time delay (usually a pulse from negative side of coil)
50 Live when starting
30 Hot Live
15 Live with ignition (switched live)
31 Earth
87 Live when relay is on
87a Live when relay is off (changeover)
87b Second live like 87

HTH

Dear Flybynite
A VERY BIG Thank you to you I really thought I was going to struggle to get an answer to this one!!!. I will do a proper bench test over the weekend as the car will run for about 10 seconds the cuts out. I have a good spark and fuel but it will not run which is really annoying after fitting a new fuel pump.
I would have replied sooner but I am not getting emails from this post.Probably my fault lol

Post Sat Aug 24, 2024 12:41 pm

Hi Flybynite

Just been checking the relay and I do not have a 87a pin. Only 87 and 87b which I presume switches from one to the other.

I Have now been testing it using a multimeter and I think Pins 30 and 31 are equivalent to the 85 and 86 Pins of a normal relay and that I should have an Ohms reading.
Sadly I only get OL so I think the relay is dead.

The only other reading I get which is continuity between Pins TD and 87b

Post Tue Aug 27, 2024 11:58 am

[url][viewtopic.php?t=245248/url] Brianmoore the guru posted this article up some years ago, it may help you.

Post Tue Aug 27, 2024 5:04 pm

HartgeH27 wrote: ↑
Tue Aug 27, 2024 11:58 am
[url][viewtopic.php?t=245248/url] Brianmoore the guru posted this article up some years ago, it may help you.

Thank you so much for posing this I will have a good read later.

Post Tue Aug 27, 2024 5:28 pm

The zone Wiki works wonders !

Post Wed Aug 28, 2024 7:22 pm

HartgeH27 wrote: ↑
Tue Aug 27, 2024 5:28 pm
The zone Wiki works wonders !

Most of the time I would agree with but on this occasion sadly not

Post Wed Aug 28, 2024 7:26 pm

I read through the Brain Moore link with great enthusiasm which was very interesting. Thanks HartgeH27. I then promptly went out to my car with hope in my heart in search of relays by the ECU but sadly there aren't any so back to the drawing board!!!

Post Wed Aug 28, 2024 7:47 pm

Oh well that is one avenue of investigation discounted, good luck with your problem resolution

Post Fri Aug 30, 2024 8:05 am

HartgeH27 wrote: ↑
Wed Aug 28, 2024 7:47 pm
Oh well that is one avenue of investigation discounted, good luck with your problem resolution

Thank you going to have a recheck at the weekend someone called Brutus has been in touch and says he may have a spare. Apparently he sells parts on this forum.

Post Fri Aug 30, 2024 8:11 am

Brutus is an old skool zoner and has been around for many years. He has a good reputation.

Post Fri Aug 30, 2024 12:45 pm

HartgeH27 wrote: ↑
Fri Aug 30, 2024 8:11 am
Brutus is an old skool zoner and has been around for many years. He has a good reputation.

Mart.

Post Fri Aug 30, 2024 10:36 pm

Brilliant guys!! Thank you. Good to know as its so easy to get caught out by none reputable people

Post Sun Sep 08, 2024 10:21 am

Well it has been a manic week here hence why I haven't posted but the news so far is that the readings i am getting from the pins is inconsistent so I am going to order a replacement. I will check if Brutus has one in stock first and then go from there (Fingers crossed).

Post Sat Sep 21, 2024 4:22 pm

Again apologies for the slow update but i do have some good news I have managed to buy a relay from Brutus and I should have it in the next week or so. Hopefully I will be able to get my car running again.
I was told that it is the bmw e30 preface fuel relay siemens --1286727. either way I hope it works!!!
I will do a comparison test before fitting on the pin readings.