Re: 3:car needed+headlamp sockets+head gasket?(quite long)

["Fred Munro" <munrof@isys.ca>]

 Hi Erik;

  The problem with the DOT lights is in the design of the reflector and lens
system - increasing bulb wattage just provides more lumens to scatter in all
directions.
    The discolouration at the connectors is from the contacts heating up,
not from heat from the bulb. The 900x contacts have a low surface area and
are pretty well limited in the amount of current they can carry to that
required by normal wattage bulbs. The spade contacts on the Euro Hx bulbs
are much larger and can carry more amps. Keeping the contacts clean goes a
long way to keeping them cool - a little surface oxidation increases
resistance and rapidly results in overheating. This is why a contact
enhancer (Stabilant 22A) or a dielectric grease can help, although I have
read that dielectric grease can result in a resistive silicate layer forming
on the surface of the contact.

Fred Munro
'94 S4  94k km

----- Original Message -----
From: "Erik Addy" <erik@aero.und.edu>
To: "Robert Myers" <rmyers@inetone.net>; "Allan Jones" <ampj@mediaone.net>;
"Quattro List" <quattro@audifans.com>
Sent: Sunday, December 12, 1999 5:17 PM
Subject: RE: 3:car needed+headlamp sockets+head gasket?(quite long)


>
> > My personal experience with the Competition Unlimited (nice folks, BTW)
> > wiring harness (including sockets) and 80/100 watt 9004 lights (or the
> > lower values above stock) was totally unsatisfactory in my first
> > '89 200tq.
>
> Hmm.... Interesting.
> I built my own wiring harness, using 12 ga wire and Hella relays,
terminated
> in blue-colored "heavy-duty" comp ltd bulb sockets.  These are made out of
> a seemingly softer plastic than o.e., and have (if I remember correctly)
> 14 gauge pigtails.  They came with dielectric grease in the terminal
holes.
>
> Using 65/100 9007's I have had no problems, now over a year since I did
the
> conversion and not even a burnt out bulb.  After reading your post, I went
> to take a look at the connectors.  On the high beam side of the comp ltd
> socket, there is some slight discoloration (brown).  There is very little
> of this discoloration.  The low beam side is fine.
>
> I wonder if the metal housing of the 4kq lights is helping to disipate
> heat beter than the plastic housings on the 200?  My 200 has euros, but
> I was planning on doing the 9007 conversion to my brothers 5ktq.
>
> After reading bout your problems, I will probably go with 70/80 watt bulbs
> to prevent this problem.  Frankly, even w/ 100w's the high beams still
> suck on the 4kq, so I don't really think I will loose anything.
>
> Erik
>
>