Rubbish yellow relays!

I have discussed this before as part of my starter troubles thread (link) and I know @Brown has had similar problems. The standard yellow relays are just terrible. Both the fuel pump relay in my td5 and the starter relays in my 110 have the same issue where by wobbling the relay makes them switch on and off. The issue is not a loose connection with the wiring and the spades at the base connector as these are new and have been squeezed together to give a tight grip, nor is it other wiring issues as the whole loom is brand new from autosparks. The issue is definitely internal to the relay. Both relays have been replaced with new and this cured the problem with the fuel pump for about 9 months before it returned.

@mystery mentioned that this is known issue with the yellow relay and they have a tendency of breaking their soldered internal connections if forced sideways (wiggling them) whilst in the holder quite simple to check by carefully removing the plastic case and re soldered if required. I have not yet checked the failed ones but this is on my list. Even so this seems to be either a fairly poor design or poor quality of parts.

I am in the process of looking into solid state relays and seeing if they would work for this application, I know they are more expensive but if they last longer it will be money well spent. Especially as the yellow ones are not cheap either considering they are just a standard relay! This thread is really just to get other peoples expricance and if anyone else other than the two mentioned above has had similar problems and what the cure was.

I don't think I have ever changed a factory fitted relay on a car in 30 plus years, 20 of them driving land rovers.

lynall said:

I don't think I have ever changed a factory fitted relay on a car in 30 plus years, 20 of them driving land rovers.

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I dont think I had until I had the fuel pump issue with the TD5. That seems to have jinxed things as I now have the same issue with the starter relay on the 110. Just very annoying. the hella solid state relays look to be 20amp, but the yellow land rover ones look to be 40amp so I need to work out if I can get a higher rated solid state or if I actually need 40amp

I can't imagine that the fuel pump needs more than 20A, if that.
The starter relay will likely just be the solenoid power, again I would be fairly surprised if it needed 20A too.

10A in both would seem to be more realistic IMO

On looking at some of the wiring diagrams do solid state relays work differently to standard relays? I was hoping for a direct replacement as I have just fitted a brand new loom so do not really want to have to cut it about to modify things. Doe solid state require a switched earth rather than a switched 12v that is currently there?

It's the same as a coil version ....

Put 12V onto P1 and the voltage on P3 is passed to P5 .... take the voltage away and the relay opens.
You could switch the GND (P2) - permanent 12V to P1 (P1 to P3) - floating is NO and grounded is NC

miktdish said:

It's the same as a coil version ....
View attachment 292036
Put 12V onto P1 and the voltage on P3 is passed to P5 .... take the voltage away and the relay opens.
You could switch the GND (P2) - permanent 12V to P1 (P1 to P3) - floating is NO and grounded is NC

Click to expand...

I was looking at this diagram from hella:

The Hella version has P30 (feed) internaly connected to P86 (the P1 on the ESR10 relay) so the 'trigger' is to drop P86 (P2 on the ESR10) to ground.
As the solid-state 'coil' that fires the relay is connected through P30 (+) to P86 (GND) you have to use a ground trigger as the live is internally connected.

If it fits your socket then the ESR10 should be a plug and play as (I think) your Defender provides a voltage to fire the coil on P1 (P86) rather than pulling the pin low.

Yes, but as I've said in another thread, check which pins perform which functions. Even if the pattern is the same, they can differ in terms of which ones operate the switch and which ones carry the current to the appliance. I think that's what @miktdish is saying in rather more technical terms.

dag019 said:

On looking at some of the wiring diagrams do solid state relays work differently to standard relays? I was hoping for a direct replacement as I have just fitted a brand new loom so do not really want to have to cut it about to modify things. Doe solid state require a switched earth rather than a switched 12v that is currently there?

Click to expand...

Some do YES!