Swords in all V8 cars myth solved + more...

[Mike-AZ]

My 6/93 build-date 540i does not have a sword, just the resistor cube. So, whom ever posted a while back that there was, needs to be shot. Just kidding. Anyway, I also found out why my HVAC system would randomly shut off during normal operation or would stay on after the car was shut down. It is a worn blower relay (yellow cube in the fuse/relay box). Now here's my new dilemma...I opened the relay and cleaned the gunked up contacts and put it back in. It seemed to be fine for the rest of the day, but then the problems started again. So, today I opened it back up only to find that the contacts were once again all burned/gunked. Here's my question, do I need to buy a new relay and that's it, or is the quickly failing relay indicitive of a worn-out blower motor and I should replace that as well??? I would hate to buy a new relay only to have it go bad quickly because of the blower itself. Thanks -- Mike

[Ross]

Relays are cheap. Swap it with another one and see what happens.

[Bill R.]

etc are causing enough amp draw to cause the relay contacts to burn quickly. I'd buy a relay anyway though but plan on probably having to buy a motor.

My 6/93 build-date 540i does not have a sword, just the resistor cube. So, whom ever posted a while back that there was, needs to be shot. Just kidding. Anyway, I also found out why my HVAC system would randomly shut off during normal operation or would stay on after the car was shut down. It is a worn blower relay (yellow cube in the fuse/relay box). Now here's my new dilemma...I opened the relay and cleaned the gunked up contacts and put it back in. It seemed to be fine for the rest of the day, but then the problems started again. So, today I opened it back up only to find that the contacts were once again all burned/gunked. Here's my question, do I need to buy a new relay and that's it, or is the quickly failing relay indicitive of a worn-out blower motor and I should replace that as well??? I would hate to buy a new relay only to have it go bad quickly because of the blower itself. Thanks -- Mike

[Ross]

etc are causing enough amp draw to cause the relay contacts to burn quickly. I'd buy a relay anyway though but plan on probably having to buy a motor.

Yup, if the draw is enough to fuse the contacts that would explain the fan continuing to run.

[Mike-AZ]

OK, thanks guys for all the input. I'll probably end up just playing it safe and replacing the fan blower as well as the relay. Is that blower hard to replace in a 540i? -- Mike


1994 BMW 540i (141,000 Nikasil miles)
1984 BMW 533i (200,000 miles, 5-speed)