Need Help With Relays

[guillermoto]

How many amps is required for the EFI main relay? The Toyota repair manual has no continuity test for the blower high relay nor for the heater relay. So I also need a continuity test procedure. Anybody out there who can help? Thanks

 

[blkprj80]

The EFI relay is under Engine, SFI System in your service manaul.

It says it should show continuity between the pins indicated. You're measuring a piece of wire, so the resistance will be fairly low, like 10's of ohms at the most.

What year?

The power window relay is the same as the EFI relay. I don't think the others you mention are interchangeable.

What trouble are you having? Knowing that might help us to form an answer that could lead you in the right direction. Otherwise, how many amps is volts (12 to 14) divided by resistance. That's for the coil side. For the relay contacts, I don't know, but I'd guess around 20 to 30 amps.

 

[maxamillion2345]

Shouldn't take many amps at all, I'm not sure how many ohms Toyota specs for their relays but I'd expect it's pretty standard you could probably compare to a normal bosch relay, 100 ohms?. On the switch side you should have almost no resistance with the coil energized.

 

[noncompliant]

Shouldn't take many amps at all, I'm not sure how many ohms Toyota specs for their relays but I'd expect it's pretty standard you could probably compare to a normal bosch relay, 100 ohms?. On the switch side you should have almost no resistance with the coil energized.

If I may help, you probably know a relay is nothing more than an electrically (current loop) operated switch. Here's how I test relays on oil eqpt: first, disconnect all the wires (label or take a pic!) on the primary and secondary sides. (you dont want to put power into either the source or the load(s). Make yourself a fused wire (I have wires with a small 1A fuse - probably not essential, but may help short something inadvertantly - and alligator clips) that you attach to the input side. Remember relays are either NO (Normally Open) or NC (normally closed). so when power is applied (your 12 or 24V or whatever the relay is rated for) to the input terminals, the switch on the load side (the current in the coil generates a magnetic field pulling the switch open or closed). If the relay is doa/dead, it wont' work at all. I often dont trust that, and activate it quickly/repeatedly. Btw, i FORGOT, on the load side you have your (ohm)meter connected - you probably already knew that. switching on and off should open/close the switch. If you think it may not be working each and everytime without fail or hesitation, much more likely, replace it. Also, it often is missed: relays are rated for the current thru the load side. Dont put in a 10A relay when your load sucks 30 for example.

 

[guillermoto]

Hi, and thanks for these initial replies! This is for a 91 FJ80 3FE.