Compressor Relay

[SeanC]

I’m over on Stradbroke Island and the R7 compressor relay has failed. Swapped with the R9 heated windscreen relay. Compressor runs again. Any problems using R9 relay in R7position.

Another big thumbs-up to the GAP diagnostic tool. Read fault. Googled fault code. Took me to DISCO3.CO.UK. Check relay. Problem solved in 10 mins.

[scarry]

Same or larger amperage relay, it will be fine.

Slightly smaller, it should also be fine until you get home and replace it.

[Tombie]

I’d recommend checking the compressor and servicing it when you get back. The relay failing is likely due to increased current draw from the compressor.

[DiscoDB]

If I recall correctly (without going out to car to check), R9 has the same amp rating as R7 and so becomes your spare for the air compressor.

[SeanC]

Thanks everybody.

For future Reference.

Fault code was: C1A27-14 Compressor circuit - General electrical failure - circuit short to ground or open.

[Eric SDV6SE]

If the relay failed then the fuse has not done its job to prevent over current in the circuit. But easy fix by the sounds of it. Yes, check the compressor as the only reason it can overload if it cannot move enough air, so dessicant and filter change required,check the piston seal whilst youve got the compressor out.

[DiscoDB]

I’d recommend checking the compressor and servicing it when you get back. The relay failing is likely due to increased current draw from the compressor.


If the relay failed then the fuse has not done its job to prevent over current in the circuit. But easy fix by the sounds of it. Yes, check the compressor as the only reason it can overload if it cannot move enough air, so dessicant and filter change required,check the piston seal whilst youve got the compressor out.

Good pick up re this being an early warning sign of a problem with the compressor.

It is a 60amp relay on a 60amp circuit - but does work very hard and must be operating close to its limit. The contacts end up welding together - hence the fault to earth as I believe the relay forms the earth circuit for the compressor.

I upgraded mine to a 70amp relay - so could end up blowing a fuse instead.

[PerthDisco]

If the relay failed then the fuse has not done its job to prevent over current in the circuit. But easy fix by the sounds of it. Yes, check the compressor as the only reason it can overload if it cannot move enough air, so dessicant and filter change required,check the piston seal whilst youve got the compressor out.

That’s how mine went blowing the fuse and replaced both main fuse and relay. The unit carried on again for months without repeat only giving fault for slow to fill so a worn older compressor runs longer stressing the already old relay and fuse. That’s why new relays are provided with new compressors I imagine.

Carry a spare fuse in your glovebox or kit I recommend.

This is a helpful video I did not find till after I did a “full” compressor rebuild and reinstalled it.

Electric Motor servicing Oem Hitachi Air Suspension Compressor - YouTube (https://youtu.be/DZVpMI9LxlY)