electrical gremlin

[hdavis]

Today I noticed that when I turn on my headlights the guages change their readins. For example, the temp indicator jumps about
1/8 scale when the lights are on and drops back when I turn them off. Gas drops when the lights are on and increases when the
lights are off.

I'm assuming a ground problem since the DC volatage appears to remain constant according to my (analog) multimeter.

Any ideas on where to begin the hunt?

Henry

Henry Davis Consulting, Inc / new product consulting
PO Box 1270 / product readiness reviews
Soquel, Ca 95073 / IP reviews
ph: (408) 462-5199 / full service marketing
fax: (408) 462-5198
http://www.henry-davis.com

 

[jim bounds1]

Henry,
I think you are on the right track, the ground to the dash guage
clusters would be my guess.

Lift up the right side of the rear dash cover and find the black wire
going to the cigarette lighter. Rig a wire from it to a known good
ground and see if it helps.

If not, pull the back cover off and find the ground wire to the guage
cluster and connect your good ground there.

Next, check the battery to frame ground connection and the frame to
engine ground strap on the side of the motor. If the lights get theur
groung through the engine strap and not the battery to frame wire, the
readings may fluctuate when the current load of the lights is present.

Hope this helps.

Jim Bounds www.gmccoop.com

>
> Today I noticed that when I turn on my headlights the guages change their readins. For example, the temp indicator jumps about
> 1/8 scale when the lights are on and drops back when I turn them off. Gas drops when the lights are on and increases when the
> lights are off.
>
> I'm assuming a ground problem since the DC volatage appears to remain constant according to my (analog) multimeter.
>
> Any ideas on where to begin the hunt?
>
> Henry
>
> Henry Davis Consulting, Inc / new product consulting
> PO Box 1270 / product readiness reviews
> Soquel, Ca 95073 / IP reviews
> ph: (408) 462-5199 / full service marketing
> fax: (408) 462-5198
> http://www.henry-davis.com