Courtsey Light & Fuel Gauge (Quick Help Please)!

[PHOENIX]

OK I have been ripping through my dash board all day yesterday and so far all day today. Im getting alot done, but I have a question about the courtsey light. Ok its mounted under the dash by the heater outlet. It has two wires going to it Orange and White. When the light is OFF, both wires (orange & white) have 12volts + power. When the light is on only the orange wire has power, the white no longer has power. How does this work. As long as the bulb is getting continious power it wont light, but as soon as its only getting power from the on source then it lights. How can I hook up another courtsey light that will turn on with the one under the dash. I can figure it out, its mind boggling.

One more thing, what color wire goes to the fuel gauge in the dash? From what I can find its pink. I hooked every wire to my tester and the only that gives resistance (ohms) is the pink one. My tank is close to full and the ohms is reading 109 and up. I thought that 90ohms was full. Whats my problem here?

The painless wire harness is also giving me alot of problems and Im about to replace the plugs on it. Im not very happy with the main plug connection, its not a very good design in my opinion. It is making me very mad

The faster the better, I have to drive it to work tomorrow and I have everything ripped apart.

Ohh yeah, I got almost all of that cheesy aftermarket A/C system out, boy is it easier to work in there now!

[87 STEPPER]

Ed,

The orange wire is from the main fuse block and the white is from the door jamb switch's.

Im pretty shure the pink wire is your fuel qty. ind. and im not shure about how many ohms it should have when it's full but if thats true then that means your rehostat on the sending unit is out of calibration.

I'll get my wdm out and look at these circuits and see what's up

[swervin ervin]

Yes, the pink wire goes to the fuel gauge. What are you doing with the harness that makes you not like it? I thought it was a good design myself. You need to make sure you get all the wires crimped on correctly or they will pull out when it's unpluged. You do have a good crimping tool, right?

Besides that, what you thinking about changing it with anyway. They don't sell them at Walmart you know.

Calm down and take a deep breath and say, it will be OK, it will be OK.

[PHOENIX]

Yes I have a good crimp tool
Crimps came out fine and all, but you know how one side is female and one is male. Well I plugged it in correctly (i know there shapes ) and when I tried to get it apart it was stuck. I couldnt get it apart for anything, way way way to tight of a fit. I end up holding the tabs and putting a flat screw driver in ther and getting it apart without damage to the plug. But one of the crimps did come off during this fit of rage And as you know you have 10 connections and eactly 10 of those little metal things, couldnt they give us atleast 2 more, just is case something went wrong? Well anyway they are shaped like an arrow, I had a hell of a time getting the metal peice left inside. I went down to checker, then auto zone, then another checker and got alternator style plugs. Im gonna use four of them instead of the one big one. Im gonna lable them A,B,C, & D. It will still be more work then the one big plug, but atleast I can get them apart. The wire harness is nice, but that plug really really p*ssed me off when I couldnt get it apart. Everything is much nicer and cleaner with this harness. I have before and afters for later

Nobody knows how I can hook up another light so it comes on with the courtsey light? Ohh yeah I dont have door switches hooked up. How does that play into this problem? The courtsey light works fine, but were do I connect the new light to get power with the old light?

Thanks!

EDIT:
What about the ohms readings im getting? What does this mean, I think there probly is something wrong with my sending unit, I know there is something wrong with the switch valve.

[87 STEPPER]

Ok, as i stated befor.

The orange wire is power and the white is for the door sw. and at some point on the harness the orange and white wires are spliced togeather thats why you see power on both.

The white wire is looking for a ground thru the door sw. so when the door is opened the sw. is closed and completes the circuit to ground.

All you need to do is splice your new light assy. into the orange wire and your other to a good ground and your done. and dont worry about the colors on the wires of the new light if there differant just hook one to pwr. & one to grd.

And as befor pink is your fuel qty.

[CHaingKaiShek]

Because no one answered. I'm pretty sure your fuel sender is the same as mine.

It should read 0-90omhz if it has the same sender.

Jeff

[MidnightBlues]

Some comments about the courtesy light:

The orange and the white are NOT spliced together,this would make a short.
You read 12v on the white wire because the resistance of the bulb is low enough not to take up all the current.
If you want another light in there put the + on (any) orange wire and the - on the white if you want it switched on and off by the doors.
If you want to switch it yourself you can put the - to ground via a SPST switch.
(Or even a combination of both is possible)

[87 STEPPER]

Originally posted by MidnightBlues
Some comments about the courtesy light:

The orange and the white are NOT spliced together,this would make a short.

WRONG I looked at the factory wireing print and they ARE spliced together and it wont short cuz the door sw. is just an open in the pwr. supply path that needs to be completed it's not really getting grounded just closed to provide power form the orange wire= power form the fuse block via the white wire thru the door sw. to the lamp.

[MidnightBlues]

Bruce,maybe I'm totally wrong here,but I checked the Haynes manual and there's no splice there as far as I can see.

[PHOENIX]

OK guys check it out. There is a white and an orange wire coming from the light switch and all the way to the under dash light. The wires make no stops and dont attach to any other wires, not even each other. When the light is activated by the switch the white wire no longer has power and lets the light turn on. I attached the hot wire of the mirror to the orange wire. I then attached the ground wire from the mirror to the white wire. The mirror now turns on with the other light. But I need to figure out how to run the wire. I have a few ideas, but need to check it out more.

What usually causes a high reading in the gas gauge?

[swervin ervin]

Originally posted by PHOENIX
What usually causes a high reading in the gas gauge?

A bad sending unit.

[PHOENIX]

But what if I have two tanks and they both read high?
Could this be related to my malfunctioning switching valve?

[swervin ervin]

May be a bad ground or wiring. Just guessing here. I guess again, it's possible both senders could be going south, but I doubt it. If the valve is bad, change it first, because you need to. I don't think it would cause your gauge to read high. The gauge could be bad too, I guess.

All I know is the sender reads 0 to 90 ohms. If it's reading higher than 90, and you are sure of this, it would just about have to be a bad sender or wiring one, right? Check the wiring for a short or bad ground too.

[85 K5]

I got lost when you started talking about mirrors.

But, someone correct me if I'm wrong. The basic circuit, and how Chevy is wired, is +12v to the light (orange wire) through the light to a ground. (switch via white wire) This completes the electrical circuit, source volts through lamp to ground. Therefore you could actually wire the additional lamp to either the white or the orange wire, simply splice into it and add it into the circuit. To say a different way cut the orange wire, tie one wire from the light to one side of the orange wire and tie the other wire from the lamp to the other side of the orange wire.

[ElGracho]

We are making this much harder than it is.

Here is a diagram of the circuit:


There are two bulbs already in the circuit. The dome light and the courtesy light under the dash. They are in parallel, that is why you see +12v on the white wire with the door switch open (meaning the door itself is closed). There is no voltage drop across the dome light bulb because the circuit isn't complete. Once you shut the door switch and ground it out, the white wire is grounded, the dome light will light and you will see 0 volts on the white wire of the courtesy light socket. To add another bulb, just wire it in parallel to the two that are already there, one side orange, one side to white. If you splice it in to the orange wire, the bulb will be in series with the courtesy light bulb and they will both be dimmer than if they are wired in parallel.

[PHOENIX]

I dont have a door light or a door switch in my truck. I have one courtsey light under the dash and thats it. I tried hooking the 12v wire for the mirror lights to the orange and the ground on the mirror to a regular ground, the light stayed on all the time. When I hooked the 12v to the orange and the ground to the white it worked fine.

Ill check out my wires underneath the truck and try to track down my problem some more. Those damn switch valves are just so expensive. Ill save some $$$ then pull the bed off probly change the units, change the switch valve, clean out the tank that hasnt been used. And paint the crap out of everything

[swervin ervin]

Sounds like a plan. I hate messing with stuff. I get pissed and change everything at once. To me, when one thing goes bad, it's not long before something else quits. If money is available, do it all at once and be done with it. If you are like me, I hate to have to go back and work on the same thing again. It really ticks me off.

But, I'm not telling you for sure it's a sender(s). No telling what it is. May be the valve (doubt it), or the wiring. It's hard to say for sure what it is. These trucks do some weird stuff sometimes.

[remy]

phoenix...

just splice the positive wire on your mirror light to the orange wire on the courtesy light and the negative to the white... i did the same thing on my neon light in place of a dome light(my truck didn't come with a dome)... works on the same switch as the courtesy light... very simple... run the wires where they won't get pinched or cut and it's done...

remy

[remy]

oh, and by the way... i'm new... hello