Need help from anyone who's done a Painless wiring harness

[FLYNAVY30]

Car is a '72 C20 Suburban. Ive rewired the entire car with the Painless C10 harness. Everything works perfectly with one exception....the blinkers dont work, and when I press the brake pedal, the front and rear blinkers illuminate (steady), along with the associated dash directional lights. Ive traced the wires for all four lights back to the fuse block, and everything is run properly. The only thing I can think of is that something between the harness and the steering column isn't wired properly. Keep in mind, when I disassembled the truck, everything was working properly, so I know that the wiring within the steering column is good. Below are the connections between the steering column and the painless harness....any help is GREATLY appreciated!!

Column BLACK to Painless BLACK
Column BLACK/LIGHT BLUE STRIPE to Painless LIGHT BLUE
Column ROYAL BLUE to Painless ROYAL BLUE
Column BROWN to Painless BROWN

Column GREEN to Painless GREEN
Column BLACK/YELLOW STRIPE to Painless YELLOW
Column PURPLE to Painless PURPLE
Column BLACK/GREY STRIPE to Painless GREY

[VetteVet]

Originally Posted by FLYNAVY30

Car is a '72 C20 Suburban. Ive rewired the entire car with the 67-72 Painless C10 harness. Everything works perfectly with one exception....the blinkers dont work, and when I press the brake pedal, the front and rear blinkers illuminate (steady), along with the associated dash directional lights. Ive traced the wires for all four lights back to the fuse block, and everything is run properly. The only thing I can think of is that something between the harness and the steering column isn't wired properly. Keep in mind, when I disassembled the truck, everything was working properly, so I know that the wiring within the steering column is good. Below are the connections between the steering column and the painless harness....any help is GREATLY appreciated!!

Column BLACK to Painless BLACK
Column BLACK/LIGHT BLUE STRIPE to Painless LIGHT BLUE
Column ROYAL BLUE to Painless ROYAL BLUE
Column BROWN to Painless BROWN

Column GREEN to Painless GREEN
Column BLACK/YELLOW STRIPE to Painless YELLOW
Column PURPLE to Painless PURPLE
Column BLACK/GREY STRIPE to Painless GREY

The diagram in painless' manual does match the wiring in your description for the harness you have nor does your truck match the normal diagram for the 67/72 truck diagram. There may be some difference between the suburban and the truck harness however.

the normal color for the truck column is shown below and you can see that the connector from the truck side of the harness does not match the colors from the column side. these variations are always possible with different years, models, and the aftermarket.




Looking at the column side of the harness, the colors match the standard diagrams. The truck side has wires with stripes in them.

In your case it appears that the brake light power wire is connected with the hazard wire in the column harness. The hazard button would also have to be engaged. to make all the connections.

What you need to do is sort out the painless harness wires and match them to the column harness wires. Well Duh! LOL.

Certain wires are easy to match. Do you have the crescent connector like in the picture or the flat type that some of the later models came with?

Based on the picture and the truck harness diagram, the colors are and their functions are as follows.

Starting at one end.

Black-----------Horn relay to horn button in column.
Lt blue-----left front and left dir. light in dash.
Dk blue----------right front turn and dir light in dash.
Brown -------- Hazard lights to all turn lights.

Purple-------Normal turn lights power to turn signal switch
Yellow ----- left rear turn and brake light through the TS switch.
Dark green----- right side rear turn and brake light.
White--------Brake lights power wire and power to TS switch.

Here's how to sort the wires out.
With the steering column connector disconnected and the key off.
Measure voltage on the wires from the truck side of the harness.

Only the brown hazard wire should have 12 volts. The rest should show no voltage. The brake switch is fed by an orange wire that is full time hot so the wire from the brake switch to the harness connector, (normally white) should show 12 volts when you press the brake pedal also key off. This is critical to
your problem as you need to sort which wire is the brake power wire. It would
normally be a white wire but in your case I'm guessing it's the black wire with the gray stripe.

Turn on the key.

The purple wire is normally the turn signal feed wire and should now have 12
volts on it. If you doubt the turn signal lights wiring, you can jump this wire to the yellow and green wires in the truck side connector and the left and right rear brake/signal lights should come on and possibly blink.

You can also jump the purple wire in the truck side harness to the two front turn signal wires, normally Lt blue and dark blue and they should light up and may blink., You should also see the dash directional light. I'm guessing that the black/with lt blue and black with dk blue stripe wires are the front signal lights wires.

The horn relay wire should be easy to find. It will have no voltage on it ever, it is a ground wire from the column to the horn relay and will be the smaller wire on the relay and usually black.

Do these tests and label the wires if you determine what they do. If you need to sort out the column side it is easy to do using the multimeter checking for continuity.

[hounddogs!]

Nothing to add. However, I did want to call out Vet for taking the time to give such a thorough response. That's why I love this site.

Loren

[ItsRandy]

All of the wire(s) in the Painless harness should be marked telling what each go to, I had to use a magnifying glass to read some of the wire. That and the description in the earlier post should give you enough information to be sure you have it wired correctly.

When I wired my truck I ran independent grounds, from a ground buss bar that was grounded to the battery, to most everything, tail lights, side markers, gas tank sending unit, licence plate light, back-up lights...you name it I ran a ground to it.

I once read somewhere: "When it comes to electrical, if it's goofy...it's a ground". Be sure you have good grounds, EVERYWHERE.

[FLYNAVY30]

VetteVet, I can't thank you enough! After an hour under the dash with the voltmeter, I had everything wired up and working perfectly! I actually had it wired 90% correctly from the beginning....but for whatever reason, the black wire is the constant 12v wire in the painless harness, so I had to swap the black and brown wire and now everything works as advertised. Now I just need to figure out why the Custom Autosound radio won't turn on even though it is seeing the required switched and constant 12v source along with a ground.

[Faster57]

Is it possible that you have power feeding back thru a ground at one of the bulbs? Take one out at a time. Also if you changed sockets check them.

[pinturbo75]

is the antennae fully plugged in.....

[VetteVet]

Maybe this will help.

http://www.casmfg.com/images/Radio_M...urs_manual.pdf

[Manatee Poacher]

I just experienced the same problem after replacing damaged wiring behind the dash. I must have spent 15 hours chasing it down with no luck. I finally brought it to an auto electrician, he had it fixed in 4 hours for $100. It was worth it.

If everything worked before I doubt its a ground issue, most likely behind the dash. Good luck, that is a pain to deal with!

[FLYNAVY30]

got it all sorted out with a little help from a couple of guys in the truck section!

[FLYNAVY30]

radio turned out to be that the plug in the back of the radio wasn't completely seated....2 min fix

[El Campo]

Vettevet is the MAN! Always love to see his electrical explanations

[highwinger]

Originally Posted by FLYNAVY30

got it all sorted out with a little help from a couple of guys in the truck section!

So what was the problem & fix?


Mine's going thru a wiring cleanup now too

[vectorit]

I merged the two posts into one.

[FLYNAVY30]

Thanks vectorit! The problem ended up being a few crossed wires going from the painless harness to the column....namely the constant 12v, the hazard, and brake light wires.