Relays,ABS Main,Brake Pump and Fuel Pump?

Below was exerpted from a recent post and the Brake/Relay Section of reatta.net

Are Hella and Bosch #'s correct (reversed?) or innerchangable?

Would like to update info at reatta.net

From post:

Hella part numbers 25530905 and 25530731 work

Bosch #12065115 works.

Omron #25553347 works.

There may be others.

MR125? Advance Auto

From reatta.net:

Bosch #25530731

Bosch #25530905

Hella #25530904

Hella #25530731

Omron #25553347

The Advance Auto MR116 is no longer available but picture of the MR125 (available) indicates it has the proper bracket?

Wally.... the 8 digit numbers are GM numbers that the manufacturers (Hella, Bosch, and others) put on their relays for GM. So you could have a Hella and a Bosch with the same (8 digit)part number, but the manufacturers internal number would be different. It also appears Hella, Bosch, and others have changed their internal numbers since first introduced in the 1988 Reatta.

Why did GM have so many different numbers for the same relay? Think it has something to do with specs...intermittent duty, continious duty, and probably current rating. There is also the design of NO (normally open) and NC (normally closed). The Reatta relay only need one set of contacts, as nothing happens when the relay is off, but all the relays I have seen have both sets of contacts.

After GM stopped buying the relays, I suspect the manufacturers dropped several of the part numbers and now only make the most universally used relay design.

This (technical) information is hard to come by as sales people don't have the time of day for someone that is not going to purchase something.

I have been working on similar information on the Electro-luminescent Inverters,

GM had 6 different part numbers, I cannot get information on why they were different. I have found a company that has 4 of the part numbers and they can't/won't give me details.