No trailer lights or back up lights
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No trailer lights or back up lights
Running into an odd issue while trying to install a backup camera. Honestly not 100% sure if they were working before, but noticed after tapping into the left taillight reverse line that the back up lights aren't actually working. Neither side. Checked the fuse and it looks fine, checked for the backup 12V signal at the rear 7-pin and no power there, either. Noticed that neither trailer plug has any power at all, though, even the auxiliary or the brake lights. Do the standard back up lights and the trailer plugs share a circuit somewhere?
Tried searching, but not really finding anything super relevant. Maybe a different fuse or possibly a relay that I'm not seeing? Thanks so much
Tried searching, but not really finding anything super relevant. Maybe a different fuse or possibly a relay that I'm not seeing? Thanks so much
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Need a tad more information since they changed wiring up over the years.
However, without someone actively pressing on the brakes or having a turn signal going, you won't get power on those circuits. You won't see power even at the 12v line on some later trucks.
Did you have the truck on and in reverse when you checked the circuit? If not you won't have power to the reverse lights either.
I don't know how your back up camera works, but I wouldn't be splicing into the brake light circuit for power - as said above, you'll only get power when you're stepping on the brake pedal.
However, without someone actively pressing on the brakes or having a turn signal going, you won't get power on those circuits. You won't see power even at the 12v line on some later trucks.
Did you have the truck on and in reverse when you checked the circuit? If not you won't have power to the reverse lights either.
I don't know how your back up camera works, but I wouldn't be splicing into the brake light circuit for power - as said above, you'll only get power when you're stepping on the brake pedal.
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Ugh, sorry. Thought I had it in my signature. 2006 F250 ECSB with the 6.8 and the ZF6.
Yeah, I had the truck in reverse with the ignition on as well as cranked, both with no reverse lights. Only checked the 7-pin with ignition on, not fully cranked, maybe that's why there was no power there and the two issues are completely unrelated. I did check to see if there was power to fuse 8 (the back up lamp fuse) with ignition on and in reverse, and saw no power to that fuse, so it seems upstream of the fuse on the interior? Looks like there's also a relay at #211 but I don't seem to have another half sized relay in the box to test it with.
Need a tad more information since they changed wiring up over the years.
However, without someone actively pressing on the brakes or having a turn signal going, you won't get power on those circuits. You won't see power even at the 12v line on some later trucks.
Did you have the truck on and in reverse when you checked the circuit? If not you won't have power to the reverse lights either.
I don't know how your back up camera works, but I wouldn't be splicing into the brake light circuit for power - as said above, you'll only get power when you're stepping on the brake pedal.
However, without someone actively pressing on the brakes or having a turn signal going, you won't get power on those circuits. You won't see power even at the 12v line on some later trucks.
Did you have the truck on and in reverse when you checked the circuit? If not you won't have power to the reverse lights either.
I don't know how your back up camera works, but I wouldn't be splicing into the brake light circuit for power - as said above, you'll only get power when you're stepping on the brake pedal.
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From: St Louis
Thought I had it in my signature. 2006 F250 ECSB with the 6.8 and the ZF6.
Do the standard back up lights and the trailer plugs share a circuit somewhere?
Verify CJB fuse F08 is present and good.
Same for the reversing lamp relay.
Verify whether or not the relay "clicks" when the ignition is in RUN/Start and the transmission is shifted into REVERSE.
Report results.
BTW, if the truck is equipped with either the EC mirror or the parking aid, the (operational) reversing signal is readily available in the truck's cabin.
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Doesn't appear you've set up a signature yet. That can be done in your User CP.
I'll preface this with the observation that you likely have multiple faults since you do not have truck reversing lamps nor any activity on the trailer plugs. I'll focus on the first condition as checking it out may cause you to stumble across the reason for the latter issue.
Verify CJB fuse F08 is present and good.
Same for the reversing lamp relay.
Verify whether or not the relay "clicks" when the ignition is in RUN/Start and the transmission is shifted into REVERSE.
Report results.
BTW, if the truck is equipped with either the EC mirror or the parking aid, the (operational) reversing signal is readily available in the truck's cabin.
I'll preface this with the observation that you likely have multiple faults since you do not have truck reversing lamps nor any activity on the trailer plugs. I'll focus on the first condition as checking it out may cause you to stumble across the reason for the latter issue.
Verify CJB fuse F08 is present and good.
Same for the reversing lamp relay.
Verify whether or not the relay "clicks" when the ignition is in RUN/Start and the transmission is shifted into REVERSE.
Report results.
BTW, if the truck is equipped with either the EC mirror or the parking aid, the (operational) reversing signal is readily available in the truck's cabin.
Also tested the trailer plugs with the truck idling and still the same, no power to either 3 pin or 7 pin. Unfortunately it's the XLT trim, so no EC mirror or parking aid.
Hotshot
Joined: Jan 2004
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From: St Louis
You are checking fuse F08 under the dash, correct? It should be ALWAYS HOT.
The reversing lamp relay is also under the dash, not under the hood.
The reversing lamp relay is also under the dash, not under the hood.
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Correct, I probed the F08 fuse with both ignition on and running and am getting no voltage.
I was thinking it could be the reverse signal switch on the transmission, but I'm assuming F08 is before the switch, so the problem is upstream? Is there anything in the path between 12V and the F08 slot?
I was thinking it could be the reverse signal switch on the transmission, but I'm assuming F08 is before the switch, so the problem is upstream? Is there anything in the path between 12V and the F08 slot?
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Is there a fuse in the engine bay that supplies power to the interior back up light fuse F08? I don't see how the backup light and trailer connections are connected at all, but it's just an odd coincidence that they're both currently out and in the same area. Possibly a shared ground somewhere? I'll take another look at the rear wiring asap.
Edit: One thing I did notice is both the solid yellow and solid brown wires in the loom that goes into the driver side kick panel look to have been spliced at some point in the past. They both seem like they're crimped solidly, but figured I'd mention it since I just saw it. I can't seem to find online what those wires go to.
Edit: One thing I did notice is both the solid yellow and solid brown wires in the loom that goes into the driver side kick panel look to have been spliced at some point in the past. They both seem like they're crimped solidly, but figured I'd mention it since I just saw it. I can't seem to find online what those wires go to.
Last edited by jrp07f; Nov 1, 2021 at 04:32 PM.
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Joined: Jan 2004
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From: St Louis
Let's check a few additional fuses in the CJB. They should all be ALWAYS HOT, fed off the same source as F08. If they're all dead, then I expect a LOT of things to also be not working besides backup lamps and the trailer lights.
F02
F03
F04
F05
F06
F07
F11
F12
F13
F17
F18
F19
F20
F02
F03
F04
F05
F06
F07
F11
F12
F13
F17
F18
F19
F20
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