![]() |
|
![]() |
#1 |
Registered User
Join Date: Jul 2017
Location: Pa
Posts: 134
|
Help with dash lights
Im trying to knock off the checklist one by one on my 70 c10 that i bought a few years ago and the next thing i need to figure out is my dash lights. The gauge lights, turn signal indicators, and the heat control do not light up. Where do i start trobleshooting this? The switch or the fuse panel? The headlights dont work too so im hoping just the switch but i dont want to rule anything out.
|
![]() |
![]() |
![]() |
#2 |
Registered User
Join Date: Jul 2018
Location: Ozark, AL
Posts: 43
|
Re: Help with dash lights
Maybe the dimmer switch?
|
![]() |
![]() |
![]() |
#3 | |
Registered User
Join Date: Dec 2017
Location: Elkhart, Texas
Posts: 1,705
|
Re: Help with dash lights
Quote:
|
|
![]() |
![]() |
![]() |
#4 |
Registered User
Join Date: Jul 2018
Location: Ozark, AL
Posts: 43
|
Re: Help with dash lights
I wasn't sure if it would affect the dash lights, but it will cause the headlights to not work
|
![]() |
![]() |
![]() |
#5 |
Registered User
Join Date: Jul 2017
Location: Pa
Posts: 134
|
Re: Help with dash lights
I checked the fuses and nothing was blown. I am not getting power to the fuse for the dash lights with the key on.
|
![]() |
![]() |
![]() |
#6 | |
Registered User
Join Date: Dec 2017
Location: Elkhart, Texas
Posts: 1,705
|
Re: Help with dash lights
Quote:
Here's a clue to dash light operation.. Although the dash lights operate from the headlight switch, they don't receive power from the headlight circuit. But a certain switch does have to be "turned on" before you will see power on the dash light fuse.. The wiring diagram will sort this out for you.. |
|
![]() |
![]() |
![]() |
#7 |
Registered User
Join Date: Jul 2017
Location: Pa
Posts: 134
|
Re: Help with dash lights
I have A diagram but im not sure if they were wired the same for all years and if they werent then im not sure what year its from.
|
![]() |
![]() |
![]() |
#8 |
Registered User
Join Date: Dec 2017
Location: Elkhart, Texas
Posts: 1,705
|
Re: Help with dash lights
The wiring is similar from year to year, BUT there are differences.. Determine the year you're working with and get the corresponding diagram.. Grey is the color of the dash light circuit for most years of all GM products.. Referring to the proper diagram, trace the wire (no matter the color) on the other side of the fuse that has the grey wire on it.. I know where it goes, but, as I said-- I don't spoon feed.. You'll not learn a thing unless you dig into it yourself.. Turn on the dash lights (even if they don't come on) and check for voltage at the other end of that wire feeding the dash light fuse.. Do that and come back and tell me what you find..
|
![]() |
![]() |
![]() |
#9 |
Registered User
Join Date: Jul 2017
Location: Pa
Posts: 134
|
Re: Help with dash lights
I can see that the gauge lights are running off of the grey wire from the fuse panel. But im not sure where the power comes from to give the grey its power on the other side of the fuse.
|
![]() |
![]() |
![]() |
#10 |
Registered User
Join Date: Dec 2017
Location: Elkhart, Texas
Posts: 1,705
|
Re: Help with dash lights
Think about what you just said (typed).. You know the answer, you're just not seeing it.. When everything is functioning properly, what does one do to make the dash lights come on??? the power for the dash lights comes from whatever device is activated..
|
![]() |
![]() |
![]() |
#11 |
Registered User
Join Date: Jul 2017
Location: Pa
Posts: 134
|
Re: Help with dash lights
Actually now that im looking at it my cluster harness does not match my diagram i have.
|
![]() |
![]() |
![]() |
#12 |
Registered User
Join Date: Jul 2017
Location: Pa
Posts: 134
|
Re: Help with dash lights
Sounds like your hinting toward the headlamp switch?
|
![]() |
![]() |
![]() |
#13 |
Registered User
Join Date: Dec 2017
Location: Elkhart, Texas
Posts: 1,705
|
Re: Help with dash lights
BINGO!!!! Now, you said some other lights don't work either --- headlights I believe.. Do the the tail lights work??? If so, that rules out a loss of power to the headlight switch.. If the tail lights do not work, then check for battery power (not switched but protected by a fusable link somewhere under the hood) to the headlight switch.. If you have power to the switch, the problem is under the dash or possibly a defective headlight switch.. Don't just run out and buy a headlight switch.. Find the actual problem and fix it.. Just like the charging system problem you had --- a possible corroded connection....
|
![]() |
![]() |
![]() |
#14 |
Registered User
Join Date: Jul 2017
Location: Pa
Posts: 134
|
Re: Help with dash lights
One thing i did notice after i took my gauge cluster out this evening is that i had voltage on the grey wire. I grounded my meter to steel, not the ground wire in the cluster harness because i wasnt sure which one was the ground. So possibly the ground wire in the cluster harness is my problem?
|
![]() |
![]() |
![]() |
#15 | |
Registered User
Join Date: Dec 2017
Location: Elkhart, Texas
Posts: 1,705
|
Re: Help with dash lights
Quote:
I don't like the factory ground for the cluster.. It's comprised of a wire with a "J" clip on the end.. the "J" clip is attached to the edge of the steel dash on the edge of the cluster opening.. Given 40 - 50 years of vibration, rust, and general poor design, the ground becomes ineffective.. Loss of ground paths account for about 80% of the electrical problems in old vehicles.. |
|
![]() |
![]() |
![]() |
#16 |
Registered User
Join Date: Jul 2017
Location: Pa
Posts: 134
|
Re: Help with dash lights
Yes the tail lights work.
|
![]() |
![]() |
![]() |
#17 |
Registered User
Join Date: Dec 2017
Location: Elkhart, Texas
Posts: 1,705
|
Re: Help with dash lights
OK.. This tells us the headlight switch has power to it.. At this point I wouldn't condemn the headlight switch.. As I previously stated, you have more than one problem. I'm leaning toward more corroded connections and poor/missing grounds. Let's get the dash light problem solved, then we'll move on to the other light problems..
While you have the cluster out, check the printed circuit "fingers" where the harness plugs into it.. Polish and tweak the contacts on the harness plug, making sure you have tight and clean contacts.. A pencil eraser makes a good polishing tool for those fingers on the printed circuit... |
![]() |
![]() |
![]() |
#18 |
Registered User
Join Date: Jul 2017
Location: Pa
Posts: 134
|
Re: Help with dash lights
I checked the ground and its fine. Lights still didnt come on. I found a few bulbs that were burned out, one bulb holder has a broken contact, and a few other bulbs have corroded terminals coming out of the glass. One bulb holder is missing also. I have to go to the parts store and get some bulbs and hopefully bulb holders but i doubt they will have those.
|
![]() |
![]() |
![]() |
#19 |
Registered User
Join Date: Jul 2017
Location: Pa
Posts: 134
|
Re: Help with dash lights
Well ive gotten 3 bulbs to work so far...
|
![]() |
![]() |
![]() |
#20 |
Registered User
Join Date: Dec 2017
Location: Elkhart, Texas
Posts: 1,705
|
Re: Help with dash lights
While we're at it, let's get the nomenclature correct.. It's not "bulb holder", it's bulb socket.. You're making good progress.. Using a small pick or screwdriver, gently lift the contact tabs a small amount on the bulb sockets and polish them with fine sand paper or a pencil eraser. Also, polish the printed circuit trace where the bulb sockets make contact with it. This will create a nice tight connection for the bulbs.. Just remember --- all the bulbs are not dash lights.. Some of those bulbs are for turn signal indicators, warning lights, and one is the hi-beam indicator.. Clean and polish all of them.. No telling how old those bulbs are.. I suggest you replace all of them..
You're doing good work.. When you get all the dash lights working, we'll move on to the next problem... |
![]() |
![]() |
![]() |
#21 |
Registered User
Join Date: Jul 2017
Location: Pa
Posts: 134
|
Re: Help with dash lights
I had the parts store order me a few sockets since a few were in bad shape and broken. They are only a buck a piece so no big loss. I will have them tomorrow. I replaced the bulbs with some led's since i have a bag of them already. Cant see what they look like yet though because its too bright outside. If i dont like them i will get the filament type. I already polished everything on the printed board so i should be good to go with that. I think when i hit the turn signal i did not get an indicator lit up but cant confirm that right now. Once i get home i will mess with it some more.
|
![]() |
![]() |
![]() |
#22 | |
Registered User
Join Date: Dec 2017
Location: Elkhart, Texas
Posts: 1,705
|
Re: Help with dash lights
Quote:
This is just my opinion on LEDs.. Personally I don't like them, but to each his own.. I'd suggest you get all the lights working with conventional incandescent bulbs first. Sometimes certain LEDs can be problematic.. Get the circuits working first, then make the switch to LEDs.. This could prevent a lot of "tail chasing" on your part.. I'll be spending a lot of time today working on my truck.. However, I'll periodically check in on your progress.. |
|
![]() |
![]() |
![]() |
#23 |
Registered User
Join Date: Mar 2018
Location: Colchester IL
Posts: 284
|
Re: Help with dash lights
X2 on the led's get them working first with regular bulbs then switch.
|
![]() |
![]() |
![]() |
#24 |
Registered User
Join Date: Jul 2017
Location: Pa
Posts: 134
|
Re: Help with dash lights
Ok so i have all of the gaige lights working. I have the flashers working too. Also the turn signals sort of work. They work when you move the handle up or down until it clicks then they go out. Im hoping the switch may just need to be cleaned but im not sure how to get into the column yet.
|
![]() |
![]() |
![]() |
#25 | |
Registered User
Join Date: Dec 2017
Location: Elkhart, Texas
Posts: 1,705
|
Re: Help with dash lights
Quote:
|
|
![]() |
![]() |
![]() |
Bookmarks |
|
|