I would not wish to mix the different switches. The dash wiring harness
is different for the different switches.

The switch was not changed in later years for reliability reasons. It
was changed to make room in the fuse/relay panel for all of the power
window/door lock/etc relays and fuses. 85-89 had a separate fuse for the
dimming lights, late 89 on uses the license plate light fuse for the
dash dimming lights also, freeing up a relay mounting area above the
main panel previously used by the separate fuse.

Using the newer switch in earlier models would keep the dimming dash
lights from working at all.
Using the older switch in newer model would seem to work fine but would
remove all fuse protection from the dimming dash light circuit. Fire or
wiring damage could some day result. 80-84 models had no fuse for this
anyway but 85 on does.

Mark

Joe Federici wrote:

> Just wondering? if you've got the older switch is there any advantage
> to upgrading to the newer switch. Is it stronger, works better, or has
> any advantage?
>
> I've got an 87 with the older switch and just wondering. . .
>
> JFF
>
> On Jan 6, 2005, at 8:23 AM, Don in North Carolina wrote:
>
> You need to check Matilda's chassis number, they changed the switches in
> 1989.  If the number is higher than 24K045001, you need the newer (read
> more
> expensive) switch.  I believe that the instrument cluster dimmer is
> different in the newer vans, and there is an extra connection on the
> headlight switch for this.
>