Buying (bought) a Volvo 850 1996

[DennisCA]

No the engine heater is the engine block heater for preheating the engine before starting it up in winter. I have that and an electric cabin heater usually hooked up to a timer so I can get in a warm and preheated car in the morning.

I don't know what the diode trick actually does. I thought it would stop the SAS pump from starting, but I keep hearing sometimes a repeating chugga-chugga-chugga sound from where it should be located. If I pulled the relay above the engine fan (which controls the SAS pump based on what I've read) then it stops but that creates another error code. I have read on forums IIRC that the SAS pump had it's own relay placed somewhere stupid like far down in the engine bay but in literature I have never seen that, all the relays seem to be at the front above the engine fan.

The SAS pump has something physically broken about it's mount too, some rubber connectors that are broken entirely off.

[scot850]

Yes those rubber anti-vibration mounts/bobbins fail with age. The diode is to fool the system to thinking the SAS pump is fitted. The diode trick is so you can fully remove it or just leave it in place but not operational. If you are getting a noise from it, try drilling as suggested on the bottom of the fan portion of the case and let the water drain out of it. It may then fire back up.

Block heaters are great to have. I have contact paste to put behind them as was done in the factory to give better thermal transfer of the heat. It washes out over time.

Neil.

[DennisCA]

I am not sure but I believe mine is an immersion heater, fitted into one of the freeze plugs behind the engine.

Also I tested it today and it started working without the GFCI tripping... annoying with those kinds of faults...

[scot850]

Maybe lack of use has caused internal corrosion I'm sure you checked that the cable has not been rubbed through and the plug ends are not corroded.

Volvo fitted the OE heater we got over here to the back of the block. It is mounted high up near the exhaust manifold.

Neil.