How do you test if a relay is working ?

[Gecko]

I think the relay on my auxilliary Hella FF50 lights has gone phut.... I have an illuminated switch mounted and there is no light there - the fuse is OK and no signs of any loose wires. When I turn the switch on I hear no click at the relay so I suspect it's dead.

 

[Fanum]

On a standard ISO relay, you should get power out at pin 87 when it's switched.....check that there's power going in at pin 86 to activate it (that will be the live feed from your illumianted switch to the relay) and that there's current to drive it from the battery, so a permanent live at pin 30.

Also check the earth is good from pin 85, or the relay won't switch as well.

If all of those check out, the relay's duff......

 

[Fanum]

PS if the switch itself earths through the relay circuit, it could be that....unplug the feed to the switch (which presumably is ignition or sidelight/dip beam fed) and connect that directly to the pin 86 feed on the other side of the switch (ie just bypass it)

if that makes the relay click, the switch is fekked.

 

[Gecko]

Cheers Bill - that's my littel job for the morning sorted then I managed to get out on the bike again today ..... only the 3rd time this year but it was lovely - sun was shining - bike felt good just my hellas not working which is odd because last time out they were fine.

 

[Fanum]

Earth connections are a prime suspect after a vehicle's been stod for a while.....though relays can stick as well.

 

[hops]

can

you swap one from another part of the bike or car? Most relays are very similar.

 

[Steptoe]

you swap one from another part of the bike or car? Most relays are very similar.

Took the words out of my mouth - quickest and easiest solution. Swop over with a relay in your fuse box.

Takes about 30 seconds

 

[hops]

GET IN

Took the words out of my mouth - quickest and easiest solution. Swop over with a relay in your fuse box.

Takes about 30 seconds

Beat the Guru

 

[Gecko]

As happens - I had a spare relay in my box of bits - but it didn't solve the problem so I have been looking further into the tangle of wires and there seems to be an internittent loose connection but I haven't found it yet . Lots of zip ties litter my garage floor as I work my way along trying to find where it is..... I have power back to the switch but only sometimes the search continues....

 

[hops]

probably

stating the bleedin' obvious but check out the earth side first, (you could make up a fly lead with a length of wire and wire it straight to the battery and earth terminal then positive to positive on the relay). This will eliminate any connections and at least tell you which circuit you need to look closer at. If the earth is okay check connectors and then 'pinch-points' for chaffed/stretched wires.