Author Topic: no rear lights  (Read 26842 times)

Offline bd

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Re: no rear lights
« Reply #30 on: May 24, 2013, 08:33:26 AM »
On that style fuse box, the flasher at the top left is the hazard flasher.  The turn signal flasher is a divorced type that plugs into a two-wire connector hanging loose out of the harness.  It will have one dark blue and one purple wire running to it.  It sounds as though the turn flasher is either faulty or missing entirely.  Look around the driver side under the dash and you should be able to find it.

The black wire is the horn circuit and the brown wire is from the hazard flasher.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline 78C10 sleeper

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Re: no rear lights
« Reply #31 on: May 24, 2013, 03:19:16 PM »
I found the flasher and checked the wires the red and black have power the green wire dosent even with the turn signal switch on. Is this consistent with a bad flasher or is it just best to replace it

Offline bd

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Re: no rear lights
« Reply #32 on: May 24, 2013, 04:19:08 PM »
I found the flasher and checked the wires the red and black have power the green wire dosent even with the turn signal switch on. Is this consistent with a bad flasher or is it just best to replace it

Red, black and green... three wires?  Are you sure you're not looking at the horn relay?

The turn flasher will have two wires, dark blue (ignition power) and purple (to the turn switch).  The hazard flasher and the turn flasher are the same part number, so will appear similar in shape and have only two terminals.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline 78C10 sleeper

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Re: no rear lights
« Reply #33 on: May 24, 2013, 04:49:21 PM »
This hangs down beside the fuse box its square I don't see any kind of component that look like the other flasher (hazard flasher) there is only the one round component om the fuse box it may be missing Idk thanks

Offline rich weyand

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Re: no rear lights
« Reply #34 on: May 24, 2013, 05:00:13 PM »
Post a pic of the fusebox.
Rich

"Working Girl": 1978 K-10 RCSB 350/TH350/NP203 +2/+3 Tuff Country lift

Offline 78C10 sleeper

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Re: no rear lights
« Reply #35 on: May 24, 2013, 05:53:02 PM »
I tryed  to upload one it says its to big sorry im new new to this whole thing is there another way to post it

Offline bd

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Re: no rear lights
« Reply #36 on: May 24, 2013, 06:27:41 PM »
Go here for a "How to" to resize pics.  You can also use MS Office Picture Manager packaged with some computers, etc.

I agree, post some pics of the fusebox and up around both sides of the column.  The turn flasher might be missing, but unless someone removed the connector, you should be able to locate the plug under the dash.  As I recall, some vehicles had them clipped upside down to the sheetmetal behind the dash panel somewhere left of the ashtray.  You may have to lay on your back and look up.  The flasher can be metal or plastic.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline 78C10 sleeper

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Re: no rear lights
« Reply #37 on: May 24, 2013, 09:05:37 PM »
I wont be able to access a pc for the next few days im on my phone. But tomorrow im going to try and trace the wires to find it I will post the pics as soon as I can get to a pc

Offline 78C10 sleeper

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Re: no rear lights
« Reply #38 on: May 25, 2013, 05:34:48 AM »
Ok guys I found where the flasher goes :D I traced to purple wire back to the fuse box but one of the spade connectors had came out or had ben removed so I traced the green wire and put it back in the fuse box now the flasher Is working both ways and the green arrow lights in the dash are working but the rear lights still don't blink thanks

Offline bd

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Re: no rear lights
« Reply #39 on: May 25, 2013, 07:45:11 AM »
Now, we're back to this.....

  • Switch the ignition ON and turn signals ON (either direction), then use a test light to check for power at the yellow and dark green wires entering/exiting the turn signal switch connector under the dash at the right side of the steering column.  With the turn signals ON you should see power at the yellow (on left turn) and dark green (on right turn) wires....  Post up what you find.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline 78C10 sleeper

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Re: no rear lights
« Reply #40 on: May 25, 2013, 08:43:52 AM »
Ok I have power to the purple and yellow but not the green

Offline 78C10 sleeper

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Re: no rear lights
« Reply #41 on: May 25, 2013, 08:54:34 AM »
Also the flasher seems a little slow to me

Offline bd

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Re: no rear lights
« Reply #42 on: May 25, 2013, 09:07:36 AM »
As you know, the purple lead comes from the turn flasher; it's power into the turn switch.  The yellow lead is power out to the left rear turn/stop lamp.  Green is power out to the right rear turn/stop lamp.  Since the brake lights work, and they share the rear wiring with the turn signals, when you have power on the yellow wire (during left turn), you should observe the left rear lamp brightly illuminate.

However, yellow should be 'hot' only on left turn or with the 4-ways ON.  Is this the case?

If the green wire is not 'hot' with the right turn signal ON, replace the turn switch.

A 'slow' flasher may be due to insufficient load, because the rear lights aren't working.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline bd

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Re: no rear lights
« Reply #43 on: May 25, 2013, 10:28:57 AM »
There's a caveat:  Using a voltmeter, check for power on the dark green and yellow wires at the turn switch connector with everything turned OFF, except the tail lights.  Make sure the running lights are ON when you do this.  Post the reading.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline 78C10 sleeper

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Re: no rear lights
« Reply #44 on: May 25, 2013, 05:07:14 PM »
Ok tested the wires and the green and yellow have power and blink with good voltage but the purple has no power