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Working on a poorly lit instrument lighting problem. I pulled the speedo/tach module out----Surprise! There are WAY more lightbulbs than the 82 Shop Manual shows. Shop Manual says there should only be 3 bulbs for backlighting the guages. I count 14 bulbs plus room for one more! I have id'd a few.....
#4  are L and R turn signal
#6 is high beam
#12 is brake warning
Can anyone point me to a diagram or pic that identifies the rest please?
Someone has installed a 165mph speedo in this unit...it works well, but maybe a bit over the top on this mild mannered cruiser.
1, 2, 3, 7, 8, 9, 10, 11, 13 are all backlights.
I think 14 was for the choke warning light, but does nothing on an 82, they just left the lamp there for some reason.
Wired that the shop manual for the 82 says there's three lights for backlighting, the 81 manual says 9.
THX for all inputs!
Not really an electric expert here....think I would like to put 12 volts across pins 4 and 10 in the Wilcox schematics and see if I get full illumination of all 9 backlights. Anybody know if thats a good test without frying my tach circuits? I have a quality 12 v power source with selectable/variable output (11-14v). Is this a good way to test dimming capability?
FYI....the source of my confusion....82 Shop Manual appears to show only three illumination lights in the Tach/Speedo cluster. Same page shows correct number of illumination lights in the center console gauge cluster.
With the dash on the table like that, It should be easy to pull the tach totally out of the dash- no risk of cooking it that way. Also be a good time to clean up and maybe refinish the inside of the housing.
And looking at Willcox' diagrams, it looks like you are correct. Standard incandescent bulbs will respond to low voltage with decreased output. So that is a good test for dimming.
Also, while you have the dash gutted like a fish, check the ground on the left A pillar just above the hood release. Clean up that ground.
With the dash on the table like that, It should be easy to pull the tach totally out of the dash- no risk of cooking it that way. Also be a good time to clean up and maybe refinish the inside of the housing.
And looking at Willcox' diagrams, it looks like you are correct. Standard incandescent bulbs will respond to low voltage with decreased output. So that is a good test for dimming.
Also, while you have the dash gutted like a fish, check the ground on the left A pillar just above the hood release. Clean up that ground.
Big THX, Great tip on the ground wire. Will clean that ground !
FYI....the source of my confusion....82 Shop Manual appears to show only three illumination lights in the Tach/Speedo cluster. Same page shows correct number of illumination lights in the center console gauge cluster.
Note the text to the right side of the box - it says '9 Lights Total'.
Oops - TimAT beat me to it! ;-)
Last edited by bradleyb66; May 18, 2017 at 03:18 PM.
Oops!....lets see......how about......Old Man syndrome, the cat ate my homework, need stronger prescription, fine print? Fine Print....We dont need no stinking fine print! Choose any excuse you like, but a serious thank you for helping!
82 Inst Panel lighting (tach/speedo)
