Your brake booster is in roughly the same location as the relays, that may
be where your hissing is coming from.
Don
----- Original Message -----
From: "David Clarkson" <dvdclarksn@AOL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Monday, June 06, 2011 9:45 PM
Subject: hissing relays?

I've been listening for something on my vanagon for a while. There is an
audible hissing noise that seemed to come from one or both of the relays
used for the very common headlight upgrade. I thought at first that there
was some sort of grounding problem tied into either the amp, crossovers or
stereo receiver but recently disproved that when the radio was disconnected
completely and removed. I have also had pulled the fuse on the amp as well.
I still had the hissing noise that would continue for about a second after
the engine was shut off. The noise occurs whether the headlights are on or
off. My question is could this be a grounding problem with the relays or
simply one or both of the relays themselves? This is the second pair that I
have had after one got broken when it came loose in the dash and when a fuse
for the relay power was damaged it melted down the other. The original pair
did not cause any hissing but it seems that I changed something like maybe
the grounding point for the relays. Anyone out there had a similar problem
or maybe some explanation or fix. I have heard of buzzing relays? before but
not one that mad a hissing sound like air being let out of a tire. Thanks
for any insight that anyone can offer. I'm thinking that I might just buy a
couple more and maybe get a slightly more expensive and hopefully better
quality relay. With this 21 yr. old van that is approaching 300k on a
rebuilt engine I really am tuned into any noises especially one that might
mask a more serious noise.

David Clarkson
1990 Westy Ssssssss....