280z Bosch Relay Correlation? Stock Relay vs Porsche Relay

[kyle146]

3 minutes ago, Zed Head said:

There's a 120 and and a 121.  The 121 says "Jetronic", the 120 doesn't.  Wonder if diodes/resistors is the difference.  I know that their typical 5 pin relays come in different flavors.  Same basic functions, just some have a few extra parts inside.  Usually they show it on the cover, but these don't.

https://www.amazon.com/Bosch-0332514121-BOS0332514121/dp/B006NYJ328

https://www.amazon.com/Bosch-Automotive-0332514120-Relay/dp/B004Z0W1C6

The pinouts on that 121 don't seem to match up, maybe a later year revision?

[Zed Head]

Different cars, for sure.  The 120 is the one you want, apparently.  I wonder which Ford used it.

[Mike]

Only real way to compare is to open the Bosch relay..  just my opinion.  Would be great info for others if you're willing to sacrifice a good relay.  😉

 

[Zed Head]

Some work with a meter and a battery, should do the job.  Measure resistance and direction.  A fun project.

[SteveJ]

17 minutes ago, Zed Head said:

Some work with a meter and a battery, should do the job.  Measure resistance and direction.  A fun project.

Exactly. Does anybody have a spare Bosch relay they want to send me for testing?

[grannyknot]

Having parted a few BMW's I have quite a collection of Bosch relays, what kind do you want?

 

[SteveJ]

53 minutes ago, grannyknot said:

Having parted a few BMW's I have quite a collection of Bosch relays, what kind do you want?

 

Well, the intent was to test the EFI relay. Do you happen to have one of those that match the ones earlier in this thread?

[kyle146]

Just bought one, should be here this week. Will do some testing!

Edited May 31, 2021 by kyle146

[grannyknot]

1 hour ago, SteveJ said:

Well, the intent was to test the EFI relay. Do you happen to have one of those that match the ones earlier in this thread?

I think so, it's still attached to the wiring harness, I'll drag it out tomorrow.

[Captain Obvious]

Yes, I believe with a power source and some crafty meter work, one could determine if those extra components are included with the Bosch unit. I suspect they are.

Oh, and by the way... There are two diodes inside the assy (not just one), so I edited my post above.

10 hours ago, Patcon said:

What are the ramifications of not having those components?

Hmmm... I'd have to look into that, but I bet the ramifications are unpleasant. Probably not "light the car on fire" unpleasant, but maybe "fuel pump runs when it shouldn't" kind of unpleasant. If you want me to dig into it, let me know.

[Patcon]

I was asking the next Obvious question, sort of for posterity's sake

[Captain Obvious]

LOL. 

Yeah, it kinda makes me wonder a little too. There have been people who have "constructed" a fuel injection relay out of two independent generic relays. I wonder if those people included those additional components.