Are all the round relays interchangable?

jwakil · jwakil's Garage

Are the round relays for the AC and the fuel pump and other things in the trunk and engine compartment the same? I want to have a spare in case one goes out but are they different AMP ratings and if so, can I just get the highest rating one for emergencies?

tirwin · tirwin's Garage

The black ones are all the same. The red fuel pump relay is different. At least that is the case for SC's.

ossiblue · 08-19-2015, 06:35 AM

Quote:

Originally Posted by tirwin

The black ones are all the same. The red fuel pump relay is different. At least that is the case for SC's.

^^This^^, and it's for all 911s from 76 onward.

The red relay is for the fuel pump and has an internal diode that prevents reverse electrical flow through the relay coil when the magnetic field collapses. You can use a red relay as a substitute for a black, but it is not recommended to use a black in place of the red unless it is an emergency. If you are thinking of carrying spares, buy each type.

BlueWing · BlueWing's Garage

I have looked in the past but never found the specs of the black round relays. Anyone know what the current capacity for the contacts are?

Terry

jwakil · jwakil's Garage

Well, sounds like for emergencies if I just get a red I should be fine.

OsoMoore · OsoMoore's Garage

Quote:

Originally Posted by jwakil

Well, sounds like for emergencies if I just get a red I should be fine.

Test your backup - I've had two go bad on me, and one right after replacing it. It led to plenty of hours of headache searching for the problem elsewhere because the new relay was erratic.