Help with relays

[kopper69]

Hey guys,

Ive had a bit of a problem trying to replace the 5 pin relays in my VR. I go down to autobarn - guy there doesnt know a thing about them so i take my old relay and check little wiring diagram on the side of old relay and compare it to new relay.

There were a few different types but i matched the wiring diagram and then got a 12V 20/30A. I put it in the car and the (Fuel Pump in this case) fuse blew. So i take a closer look and i made the mistake of getting a slightly wrong wiring diagram. ie 87 and 87a were shorted on new fuse but not on old one.

So back to autobarn get another relay. Double checked the wiring diagram - yep this is it. Put it in the car and the fuse blew. Damn damn damn.

Now my old relay has 12V 20/30A.
New relay is 12V 30/40A.

This is the only difference i can see. Wiring diagram is exact but they are not compatable. Can anyone tell me what the numbers on the relay mean.

Obviously 12V is voltage but whats this 20/30 and 30/40.

Autobarn dont have 20/30 with exact wiring diagram so I will have to look somwhere else - but what do these numbers mean???

 

[Doctor Bob]

there are two types of 5 pin relay used, the trick is the location of the 87 pin
look to make sure they are the same.
the 30/40 refers to the current rating of the relay

Rob

 

[shaggerz]

As above... current rating. You can use a relay with a higher current rating, but not a lower one. Current rating is how much current (amps) the relay can switch before it becomes too resistive and gets hot and melts and burns your car down

 

[kopper69]

But which one is what? Like 30/40?

ie If 30A is the current rating that the relay would stop working what is the 40?

 

[shaggerz]

That is a good question come to think of it. I would take a stab at guessing that the lower number is the max current that can be switched, and the higher is the current that the contacts can handle without a switching operation occuring.

Hope that makes sense? Just having a guess.