Agreed. But 99.9% of short life problems I have had with this style of relay proved to be "Open them up and find green and orange powder". Wet air entered and electrolysis did the rest. Most of my personal relay failures occurred in places where it would be impossible for rain or road splash to have entered the picture.
I have had Hella, made in Portugal relays fail, some from Denmark and many non Bosch relays fail mainly those marked made in Japan. In every case a Bosch Tyco relay also made in Portugal solved the reliability problem. The failure issue wasn't subtle. A genuine Hella relay less than a year old almost cost me an engine due to cooling fan motor malfunction. Every last one of the failures was green and red powder electrolysis.
Then I tried once again using non sealed relays, but applying a gob of dielectric grease on the relay base to seal against wet air. Much much improvement for customers who had purchased LED light bars. Same brand no failures. Months till failure versus three years no failure.
So when I saw the relay in the image I went "Aha! Someone learned their lesson". Ten cents worth of sealing makes the relay better than any gob of silicone dielectric grease I could apply.
My toad's fan has a Bosch relay now. But they are anything but inexpensive. The weak point of a Bosch relay is the relay base. It's exposed so more dielectric grease gets gooshed into the electrical terminal slots to seal them up. My "test lab" is hot humid marine air. Salty with a stiff onshore breeze. For testing it's ideal.
Because of the CRUMMY female relay base brass terminals all of these relays are vulnerable. THE weak spot. I would rate any of the Bosch style relays, even OEM Bosch with German base, as being suitable for 20 amps continuous and no higher. If Delco Packard fast-on terminals were employed the rating would do up but they will not fit the base.
I purchased a 50-amp sealed Bosch type relay and base. But instead of the relay contacts being .250" they are .375". Both cost me thirty dollars plus as a package. This is damned near the outright cost of a White Rogers tower-style 100-amp continuous duty relay. Lets not talk about garbage metal can continuous duty relays...
The best contact protection is gold flashing, not silver. But only the White Rogers tower relays seem to have it. The White Rogers is sealed. And it is thirty dollars plus.
Choose wisely. I am springing for the relays in the ad. We shall see.
