Dash Light Problem

[SteveZero 10]

First off, let me say that i'm new here, and, this is my first restoration job on the 1969 mustang coupe auto 302. I'm not very car literate, so please go easy on me.

 

My question:

 

My gauge pod lights do not light up. The first thing I did was replace the fuses. I've noticed that (when the the parking lights are on) the light around the ignition lights up, and (when driving lights are on) the shifter light is on. The dome light in the car does not have a bulb. The blinker indicaters work, as does a light that says "brake system" that flashes on ignition. The push button for the hi-beams also works (but no indication in the dash)

 

I've pulled off the dash pad, but can't get the pod out to check all of the bulbs (can't get the speedometer cable detached/don't know how). The bulbs i have checked are fine.

 

any ideas?

 

--Steven

[jerry69 10]

Hi Steven... I'll try to offer a few things to try. First do you have a wiring diagram of your electrical system??? Now for a few tips..

The bulbs just power + & - ... Most wiring systems are 12 volts negative ground, The wire that runs from bulb to bulb is the positive wire that is fused. It will most likely run from the bulbs to the headlight switch then to the fuse box. So you want to trace the wire and make sure the headlight switch is good and your reading + 12 volts there at the headlight switch. The second part is a good ground (negative) The bulbs when they push into the back metal dash should be hooked up to a good ground....To test, just run a jumper wire from the metal then to maybe to the steering shaft or bolt and see if that makes a difference. But my real guess is the headlight switch.... See if you have the 12 volts from the fuse box to the headlight switch.....then pull the switch on and see if you still have the 12 volts..... then find the wire from the bulbs...pull the wire form the terminal and see if you have 12 volts there......if not then there is a problem with the headlight switch... If you do have 12 volt on that terminal then look at your ground source....Does your radio work??? There should be a grounding wire under the hood from the intake manifold to the firewall..... sometimes when people upgrade to an Edlebrock intake they forget to reinstall the grounding strap...on my 69 coupe it on the rear right side of the intake and runs 6 inches to the firewall.... hope this might be some help....

[SteveZero 10]

no, i don't have a wiring diagram. And, no i don't have a radio either.

 

I had a friend of mine (who has a '64 comet) use his volt-meter all over the place. We took out the dash and cleaned/tested all of the bulb connections (none of the bulbs are burnt out). Then we disconnected the light switch and cleaned/tested it. The circuit 'board' behind the gauges is in good condition as well. We tested just about everything, and we can't see where the problem is. There is power in the headlight light switch, we tested all of the wires, the dimmer coil has even been cleaned and tested, it should all work.

 

But, after all this, there is still no dash light (besides the afor-mentioned blinker lights, and "brake system" light).

 

I'm stumped.

 

-Steven

[ihateclowns 10]

The three areas I would concentrate on are (in this order):

 

1.) Voltage regulator. This is the piece the the "wiring grid" plugs into on a 69-70 car.

2.) Grounding Issues. Get a wiring diagram, borrow one, or PM me and I can fax you a copy of what you need. There are some grounds you needs to check out to make sure that is not causing your pains.

3.) Headlight switch. I know you have tested yours, but if #1 or #2 above do not work, I would go this route. They are relatively cheap and are notorious for going bad and causing tons of problems with these cars.

 

Clowns!

[jerry69 10]

Steven I'm looking at the wiring diagram....I will try and walk you through it blind here.... 12 volts + through the headlight switch,

 

Look for a "BLUE with RED strip wire connecting to the light switch (circuit #19A on wiring diagram), when you pull the light switch on that wire and connector should have + 12 volts.

 

That wire will go to the fuse block (4 Amp fuse)

 

From the other side of the fuse (circuit #19 on wiring diagram) wire still BLUE with RED strip will go to a wire splice. Circuit #19 now spilts into 4 more circuits, here's what their numbers are and what they lead to, same wire color

#19B To RPO Radio

#19C To Dash Lights

#19D To Heater Light Bulb

#19E To Clock Light and to Map Light

 

Printed circuit board connector to dash lights shows 2 wires circuit #19 BLUE with RED stripe and circuit # 57 (black wire goes into connector and is "SPLICED" it comes out and goes to ground)

 

So for the dash lights to work wire #19 BLUE with RED stripe will be 12 volts + to center of bulb and wire #57 the black will go to the outside of the bulb to ground.

 

On the diagram it shows #57 (black wire) as a "Y" one end into the connector and where it goes in comes out to going to ground.......

 

I'm using the Haynes Mustang Manual, there is a website with a few 69 diagrams, you'll have to zoom in but you will see the 2 wires....

 

http://students.washington.edu/jeischen/69wiring.zip

[SteveZero 10]

Wow, thanks for the feedback. I'm planning on getting a new headlight switch, just to take that out of the equation, but I'll be sure to follow those wiring directions to see if i have a problem there. Thanks again for the great feedback, I'll be sure to post when I find where the problem is.

 

--Steven

[SteveZero 10]

Okay, it took some time, but:

 

Replaced the headlight switch and replaced the voltage regulater.

 

For a while it did nothing... then, about a week later, I started her up, switched on the lights, and boom, the dash lights turned on (only one bulb was bad, easy fix).

 

So, i'm not entirely sure what the problem was, maybe a loose ground?

 

thanks for everyone's help.

 

--Steven

 

p.s. about a week ago, i noticed that my brake lights no longer flash when the brake is applied, but the blinkers work. I must have some serious electrical issues.

[SELLERSRODSHOP 13]

steven,

 

just went thru the same problem with mine. the main problem was no power to the guage lights from the headlight switch. after replacing that, the guage lights only worked when i jumped the two sides of the fuse terminal. the fuse was fine, i replaced it anyway, but had to kinda shift the fuse a little in the lugs to get contact & lights. i guess over time there might be a little corrosion or dirt built up , so will take some sandpaper on a small pocket screwdriver & clean the contacts, similar to cleaning the terminals for a good connection at the battery.

[SteveZero 10]

Yeah, I've sandpapered up the terminals on the fusebox, as well as clean just about every other contact from the battery to the dash. Thanks for the tips, but I have the dash lights working now (read a few posts back, not really sure what caused them to start working).

 

--Steven

[classy68cat 10]

Hey guys, new to the site. Have a 68 Cougar, 69 Grande, and a 70 Mach that is in process.

 

Working on the 70 lately I built this cool little device that has really helped us with electrical issues and ghosts.

 

Go to Radio Shack, ask them for a small 12v buzzer. They range from 3 to 8 bucks. Next get you a couple of alligator clips. Some red and balck wire. I made mine about 24 inches long. That way there was "no" reach issues. Put these together, I soldered all my conncetions, and used heat shrink tubing to support everything. The wires that come with the buzzer are very small and frail.

 

Now if you are searching for hot wires, wanting to know if something is on or not, you get the audible buzz from the buzzer.

 

You know I should patent the stinking thing. But thought you guys might find this useful.

 

If you own a Cougar, you better get an electrical degree or one of these.