No Dash Lights

[patrick flowers]

>
> Any suggestions on debugging my dead dash lights. The dash lights have
> never worked for me and the 4A fuse for the dash lights blows as soon as the
> lights are turned on. That is as far as I have take it? Any advice would be
> great. Thanks.

Not much help - just start with the wiring diagram in the manual and
work backwards. Did that with mine and found a bad dimmer. Your
problem sounds more serious tho'. There's a short somewhere. You might
start by looking for and disconnecting any PO added "custom" wiring.
IIRC, there's a gray wire behind the dash that goes to ground when the
switch is off. It's sometimes mistaken for a ground wire, and if wired
into a grounded chasis radio, would have the effect you mentioned(blown
fuse).

> BTW, I fetched our GMC from storage this weekend. The old battery would not
> crank her over even when jumping it with my mini-van? What does it take to
> get these beasts to crank?

I'd suspect a bad starter ground or possibly bad battery cables. My
WalMart battery works just fine.

Good luck,
Patrick
- --
Patrick Flowers
Mailtoatrick

The GMC Motorhome Page
http://www.gmcmotorhome.com

 

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>
> I have asked for a switch from the local junkyard, as I was
> afraid to ask at NAPA - it looks like something they might
> want lotsa money for (right now I don't have lotsa).

I know the feeling. I got my replacement switch from PEPBoys. Took the
old one and asked for a switch for a 73 GMC truck. When the counter guy
brought out the 73, it didn't match. He took my old one and came back about
10 minutes later with another box. "72" he announced - a perfect match,
working to this day(about five years).

> Patrick, that gray wire you mentioned - is that coming from
> the light switch?

Yep, it's part of the dash light circuit. I tapped into it for an
instrument light right above the radio. I did that not long after hearing
some folks had run into problems when installing replacement radios, which
is why it stuck in my memory. Supposedly, it goes to ground when the lights
are off. Someone installing a radio assumes it's a ground wire(how many
people install radios with the coach lights on?), which works fine until
you turn the lights on...

Patrick

 

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>

> >
> > Patrick, that gray wire you mentioned - is that coming from
> > the light switch?
>
> Yep, it's part of the dash light circuit. I tapped into it for an
> instrument light right above the radio.

IIRC, this wire is for the lamp inside the HVAC control head.

Patrick