Re: 2 questions (WOT switch)

[quk@isham-research.demon.co.uk (Phil Payne)]

In message <707e7a8c.35f999fe@aol.com> MSV96@aol.com writes:

> I had no problem "fixing" mine. Here's how I did it (has worked fine for
> almost a year since so far). (The following steps assume you have removed the
> WOT switch from the car.)
>
> 1. Carefuly pry open the switch case with a jewler's screwdriver or your
> weapon of choice. The seam is glued so it is a little tricky but does come
> apart.
>
> 2. Using liquid solder flux (rosin, NOT acid) and a very hot iron, resolder
> the connections from the internal switches to the extrnal connector. These are
> almost certainly cracked--solder them all.
>
> 3. With a relay contact burnishing tool (electronic suppliers) and good
> quality contact cleaner (i.e. Caig DeoxIT or Stabilant) carefully clean the
> contacts of the open WOT switch.
>
> 4. Clean the idle microswitch by spraying in contact cleaner while exercising
> the switch (this is really a preventative thing).
>
> 5. Seal the switch assembly back up. I used black electrical tape (color
> matches good, seals the seam, and easy to take apart for the next time--which
> has yet to happen!)

Yup.

I've given up with this procedure.  Scott Mockry has proposed that the
WOT circuit on the MAC11/12D/13A/14 is sensitive to resistance.  I now
have _three_  cases in the UK (Daryl Roxburgh, Charles Adair, John
Robinson) where I strongly suspect parasitic resistance of blocking
WOT.

I'm not rebuilding _any_ more WOT switches.  I've had _some_ success,
but the overall aggravation just ain't worth it.  Check out the new
version now being shipped by Bosch, and you'll find they've addressed
a number of the original design issues.  Keeping a bad design in use
versus allowing replacement by an improved version is a no-brainer.

--
 Phil Payne
 Phone: 0385 302803   Fax: 01536 723021
 (The contents of this post will _NOT_ appear in the UK Newsletter.)