Why URO DME Relays Fail Right Out of th Box

[86 911 Targa]

Nice pics.

How about one more showing the solder points.

Thanks,

Gerry

[umgang]

They are all junk with weak solder joints. I've had them failed right out of the box too.
Only way to be secure is to re-solder them or have them soldered.
I send mine to Steve Weiner @ Rennsport Systems - do a couple of them and you are good.
Even the Porsche branded parts are starting to be questionable. Though they are still WAY better than the after - market consumer grade crap.
You want cheap you get cheap .

[rick-l]

Originally Posted by 86 911 Targa

How about one more showing the solder points.

Like the one in the first post? I cleaned the solder flux off after I resoldered it however.

Reprint

[Walt Fricke]

Should be easy enough just to solder the wires to two standard relay holders to these pins, and figure out a way to mount the two relays separately in a place which is out of the way, off the floorpan (water), but where they are easy to replace.

When repairing these regular DME relays, whether really crappy, or just the poor design of the stock one, you should consider fitting a piece of plastic or fairly stiff foam between the PC board and the plastic case. The Porsche ones fail because those two heavy electromechanical relays make the PC board bounce up and down, and cantilevered as it is - the relay mounts in a horizontal position - the solder joints crack. If you don't add this support, you'd suppose they will eventually crack again.

[rick-l]

If anyone has one of these that they are using as a spare could you do me a favor and measure the resistance between pin 30 to 87b and also 30 to 87?

This is the resistance between the open relay contacts and on mine it reads 1-2 MEG Ohms with some indications of a strange contaminant that I can't find on the PCB.

It has to be in the area circled (orange) but getting that relay frame off would probably destroy the board.

[CountD]

URO parts=Chicom parts=the most expensive parts you'll ever buy.

Why is a URO part the most expensive part you'll ever buy?

Because you'll need to replace it 3-4 times and it still won't last as long as a German equivalent.

[KiwiJohn]

All we all really need is an adapter that routes the pins of two Bosch relays to fit the Porsche socket properly. Cheap and excellent replacements forever.

Anyone know how to manufacture stuff?

Something like this?
My effort on a single.
It works

[Walt Fricke]

The problem with this kind of thing is remembering which wires go to which spades when replacing the relay. But you can purchase relay sockets and wire them this way, which means you only have to do the figuring once.

[David Borden]

Can this be done with a single relay, or does it need two?

[Walt Fricke]

You don't have much faith in Porsche engineering, do you? A wiring diagram ought to show why two were used, and one assumes they needed to keep two circuits and functions separate.

[Tremelune]

You need two relays, but you only need two $5 relays which will last forever, instead of a $40 DME relay (which will still probably last a decade).

Most of the time it comes down to the fact that $40 for a relay to get me down the road for another decade isn't a big deal, it's just annoying. Anyone who is willing to cobble together a solution will probably just solder the broken relay properly and be on their way.

That said, someone went far enough to manufacture and sell a solid-state DME relay for the 964/993. To me, it would make a lot more sense to manufacture a fool-proof adapter for a pair of standard relays.

[KiwiJohn]

Lack of availability of a new relay prompted my fix. Not cost or reliability.

[steely]

Originally Posted by rick-l

If anyone has one of these that they are using as a spare could you do me a favor and measure the resistance between pin 30 to 87b and also 30 to 87?

have 2 test subjects for you, they both read wide-open, or "OL" w/ a Fluke 79III
relays: old obsolete 91161815400 (Porsche branded OE mfr is Stribel) and 'newer' x5401 (Porsche OE branded only)

[rick-l]

thanks