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Daniel Diewerge
Experienced User
Username: didi13109

Post Number: 17
Registered: 11-2009
Posted on Tuesday, 30 August, 2011 - 06:32:   Edit PostDelete PostView Post/Check IP

Dear all,

I have a question concerning BOSCH relays. On my car X13109 I have some non working 0 332 204 101 relays. From a later car (X36126, a Turbo R with only 35 K on the clock) that I bought as a wreck to gain spare parts from, I got a bucket full of the type 0 332 204 122 but they do not work as a replacement. The only difference I reckon seems to be the diode. Why don't they work? I know I should have paid more attention in school when electronic circuits were explained... Is there I way to get them to work in my application? The reason I want to use them is their beautifull metall housing instead of the plastic one that the available replacements all seem to have. Thank you for all advise! Sebastian

relay1

relay2

(Message edited by david_gore on 30 August 2011)
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Paul Yorke
Grand Master
Username: paul_yorke

Post Number: 777
Registered: 6-2006
Posted on Tuesday, 30 August, 2011 - 07:43:   Edit PostDelete PostView Post/Check IP

Hi Daniel,

Yes the only difference is the diode.

Depending on how the socket is wired, they will either work or not.

Unfortunately if it is the wrong way, it will try to short out whatever is driving the circuit ( not good in most circuits)

If you wish to modify them so the diode is not operating (without spoiling what looks like beautiful cases) you can connect the coil terminals to a car battery which will short and destroy the diodes. With the leads in one direction the relay will click, in the wrong direction it will short, pop, and then click.

Not ideal but easier than changing all the wiring.

H & S on batteries and sparks etc apply.
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Richard Treacy
Grand Master
Username: richard_treacy

Post Number: 2396
Registered: 4-2003
Posted on Tuesday, 30 August, 2011 - 16:11:   Edit PostDelete PostView Post/Check IP

Take care !

The Bosch 0 332 204 101 is the incorrect relay type as it has a suppressor rather than a diode. You may use it safely in some places, but not when driven by an ECU. Don’t try them on Climate Control, fuel injection etc. On later cars that even includes Windows, Headlamps and lots more.

To use them safely, you must wire a diode (EM513, 1N4007 etc) across the coil connections on the relay socket.

With a blown internal diode or no suppressor, the relay will punch 200 Volts or more in a short negative spike into the ECU and can destroy it. A suppressor-type relay like the 0 332 204 101 will punch about 40V – safer, but it may still destroy an ECU instantly or over time.

The 0 332 204 122 has the diode inside and is correct. However, if someone has pushed the leads into the socket the wrong way it will not work or may blow fuses and ECUs. Worst, if the diode is blown out then there is no protection against spikes into the electronics.

If you decide to use a relay with no internal diode, I suggest that you fit an external diode, invisible under the relay socket. The anode of the diode should connect to the -ve side of the coil lead and the cathode (the end of the diode with a stripe) to the +ve side. Pin 85 should be the –ve side of the coil and pin 86 the positive side unless someone has swapped them by mistake.

RT.
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Paul Yorke
Grand Master
Username: paul_yorke

Post Number: 778
Registered: 6-2006
Posted on Tuesday, 30 August, 2011 - 17:10:   Edit PostDelete PostView Post/Check IP

Just to clear this up a bit.

What RT is saying is correct, NEVER use an earlier NON suppressed type relay on a later car.

Daniel, who is doing it the other way around, will be OK.