Speedometer Illumination?

[JGrefenstette]

the left half of my speedometer is always light when i turn on the marker lights. but the right half is very dim. i was driving onthe interstate a few months ago and notice that when the orange needle hit somewhere around 65mph, (getting farther to the right side of the numbers) that the right side light up? is it designed to do this? stay dim untill you get much over 60mph, then it lights up the other half? if not, what the heck is going on with it? it hasnt dont it sence, and i dont usual get much over 60, sometimes ill hit 65 but rarely. im running 35inch tires so my speedometers a bit off anyway, thats why i dont hit the higher speeds as often, becuase im acutally already going faster than it says.

 

[dpuckett]

Sounds like a bulb has gone out, or you have a bad connection to the bulb.



Daniel

 

[JLEONARD]

im running 35inch tires so my speedometers a bit off anyway

I don't think is affecting the speedometer illumination unless it is making the truck go faster than the speed of light in which case there is no solution. :-laf

Probably a burned out bulb.

 

[JGrefenstette]

haha, good to hear

well the speed of light is about the farthest from what my truck goes :-laf

but since i got those gauges in i have been driving it a lot different. and i can honestly say, for the first time, that old cummins pined me to my seat!

thanks for the input guys, looks like ima be tearin the dash apart again

 

[tugboatphil]

JG, if I remember correctly the bulbs that light the dash are 194s. They are either blue or fit into a blue sleeve. I think there are 11 or 12 of them for the whole dash cluster. I have considered replacing mine with LEDs. They make a plug in replacement, but the cost is more. I was going to do it to reduce the current through the switch.

 

[JGrefenstette]

ah, good to know. thanks phil.

 

[JGrefenstette]

was cruzing down the interstate this weekend at 70+ mph. Guess what?!?! the right side of the speedometer was light up... HMMMM im actually begining to think this is a factory feature. what else could it be. its so predictable and consistant it dosent seem that somthings broken or wrong, just strange.

 

[cojhl2]

was cruzing down the interstate this weekend at 70+ mph. Guess what?!?! the right side of the speedometer was light up... HMMMM im actually begining to think this is a factory feature. what else could it be. its so predictable and consistant it dosent seem that somthings broken or wrong, just strange.

Is your pickup a 1989 or later? If it is a 1989 the speedometer is cable driven and maybe there is a vibration thingy happening. I have never seen anything in the wiring diagrams that indicate any fancy tricks like this.



((sorry I did not look close enough at your sig, it may have the info already but I got here on this slow darn computer and didn't want to go back))



Time to remove the cluster and diag it I think. .



Well after reviewing your sig,, it isn't the cable!!!! But still could be a harmonic of some kind from somewhere.

 

[Moab4x4]

JG, if I remember correctly the bulbs that light the dash are 194s. They are either blue or fit into a blue sleeve. I think there are 11 or 12 of them for the whole dash cluster. I have considered replacing mine with LEDs. They make a plug in replacement, but the cost is more. I was going to do it to reduce the current through the switch.

I did this to mine. The blue plastic sleeves were starting to melt from the heat of the 194s. I got the LEDs on ebay and they weren't too bad. I got a variety of colors.

I removed the blue covers so the colors would show and used:yellows for turn signals. , blue for brights (bad idea, too brite and it won't dim, I should have left the cover on it to dim it) and then I used reds for the dash lights. If you use blue as I did the first time, the red of the needles really doesn't show up well. Especially for the Isspro guages with red needles. I could see the stock dash OK, but the tach and boost were terrible with blue lights. I just decided to standardize on red. Wierd but it grows on you. I like the LEDs cause they are literally really cool. They don't dim really well, more of an off or on until you add a resistor to the loop and I haven't done that yet.

One or two spots if you put LED's they will never quite go off (brake warning, and a couple of others. I have enough leakage current in my PCM to slightly light the LEDs. Bulbs don't glow at that low a level so I didn't realize it until I had it all together.





I agree, bad connection on a bulb for the flickering dash lights, Why consistent with speed???????

 

[cojhl2]

I love the LED idea. I did not know there were LED bases that would fit into incandescent sockets. . I'm going to look into this.

I agree, bad connection on a bulb for the flickering dash lights, Why consistent with speed???????

The only reason I can think of is a vibration (maybe a harmonic) that sets up and closes a bad connection.

 

[Moab4x4]

leds

Internet and/or ebay search 'LED 194' and you will get tons of options.