<VV> Re: Courtesy light hook up

[Kirby Smith]

Having now spent some time studying the under-dash wiring, I am now 
convinced that for my 66 coupe, at least, it never had the floor 
courtesy lights, only the dome light.  This is consistent with the 
service manual, which shows that one or the other are used.  The 
connectors used, as well as wire lengths, do not support using them both 
together.  This led me to the realization that the courtesy light 
harness I have likely came from my wife's long defunct convertable, and 
wasn't a "leftover" part.

However, having gone this far, I wasn't going to be thwarted from adding 
the lights.  I made a pair of two-into-one flying-lead connectors and 
hooked the courtesy lights in parallel with the dome light.  Now both 
work together when either a door switch is grounded (by opening a door), 
or the panel dimmer control is rotated to the left.

I was surprised to discover that GM used the specialized type 631 lamp 
for this purpose, rather than the much more common type 97.  Having dual 
series filaments instead of a single filament would seem to be 
unimportant when the light is not directly viewed, but instead reflects 
off the carpet.  The slightly different wattages of these bulbs is not 
apparent in situ.

kirby



NicolCS at aol.com wrote:
> <snip>I  could wire up a connector based system, but I would really like 
> to know:
> How is this conection supposed to be made? <unsnip>
>  
> I haven't seen the answer to your question yet so..  The cars came one 
> way or the other, mostly and there were different sub-harnesses for each 
> type.
>  
> The sub-harness for the dome lamp style gets constant power 
> (orange) from the fuse box. Any door switch or the headlight switch 
> provides the ground, so both door switches and the headlight switch are 
> connected together and then go to the lamp (white wire). These switches 
> ground directly to the body, so there's only the one wire connected to 
> them. 
>  
> The underdash style harness works exactly the same way except the wire 
> lengths and routing are set for TWO lamps mounted under the dash. In 
> that case the right lamp (orange) goes to the left lamp, and then to the 
> fuse box for constant power.  The right switch (white) goes to the right 
> lamp then to the left lamp, then to the left switch, then to the 
> headlight switch. Either door switch can provide a ground and turn 
> on the lights or the headlight switch can ground and turn on the lights.
>  
> The exception to this is the EM accessory kit which can be added to a 
> car with or without a dome light.  In the accessory kit, each door 
> switch will only turn-on the one, local, underdash lamp and does not 
> turn on the dome lamp. In these kits, the white wire does not cross over 
> from side to side and the orange wire that plugs into the fusebox has a 
> pigtail that provides a place to plug in the existing dome lamp feed, if 
> needed.
> Craig Nicol
> 
>