73 S engine bay - left side electrical panel relays question

[mac73s]

As I get nearer to the time to start the freshly rebuilt engine from its 23 year slumber, I have a question on the various relays that are presently installed. I don't imagine these are overly expensive, and if available, would prefer to simply replace them as I've done on so many other components. In looking at what is installed vs. the PNs and descriptions in PET, I'm confused about is proper. What I currently have is (1) round black relay that plugs into the round harness end (911-615-109-01); a silver rectangular 6 pin relay (911-615-115-00) and a silver rectangular 4 pin relay (no Porsche PN, but BOSCH # 0-333-400-006). If anyone has gone through this and knows definitively what is proper and has current part numbers I'd appreciate hearing back. Thank you.

[RSTarga]

Is this what you've got? First round relay on the left is cold start; next box over is for 2 stage rear defrost; next box rpm transducer then voltage regulator. If you just have single stage rear defrost , it's an additional round relay and then no 2 stage relay;

[4SFED]

Do this help? (Should be original, the car has 36,000mi) Or do you need numbers off of each piece?

[RSTarga]

So it's reverse order transducer then 2 stage defrost. The car above has single stage defrost

[4SFED]

Wiped some of the 40 year old dust off for ya...

[mac73s]

Thank you to those who replied and offered photos. I indeed have a SINGLE round relay (same PN as those photos show) and based on the above descriptions, the two silver rectangular relays for the 2-stage defrost and transducer, but curiously NO voltage regular was installed when I got the car. The alternator has been replaced - could it have an 'internal' regulator and therefore nothing on the panel? Thanks!

[304065]

Yes it the battery charges and there is no VR on the console then someone converted to internal.

[mac73s]

I would appreciate it if anyone could provide me with a Porsche PN for the 4-pin rectangular relay...PET makes no mention of it and my dealer can't sort this one out. In looking at the wiring diagram for my 73 S, it is for the 'speed switch' with wiring run to the 'micro-switch. The terminals on the relay are marked 1,2,3,4. Thank you!

[304065]

http://forums.pelicanparts.com/porsc...ds-warren.html

[kentf14]

Ravi, where did you get you info on the voltage regulator? All of the original '73 units I've seen have been metal boxes like the one in my old photo below. The plastic Marchal box you have would likely be a later replacement.

Some 73 regulators were mounted 90 degrees to the picture originally posted. Regardless, if you don't have either version, then it's probably internal to your alternator. Do you have the SEV Marchal alternator, or something else ?

By 73S panel before restoration. 3300854, Feb '73.

Attachment 291970