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Discussion Starter #1
Ok I wanted this to go into Electrical but getting frustrated after looking for an hour and not finding a way to post in Electrical. So here it is...
I'm looking for some advice on my reverse lights and backup radar thing. I have an '07 with the manual trans. The backup radar thing was the 1st to go. maybe a couple of years ago. It now just gives a long beep at the beginning and short beeps while the truck is in reverse. No radar Geiger Counter that your coming close to anything anymore but I was ok with that.Kinda don't need it anyway. Maybe 6 months ago I decided my reverse lights weren't bright enough so I go a pair of LED's from Diode Dynamics. But now they're dim too. Thinking It's a bad connection or a bad ground? I don't think the radar and dim lights are related but I'll leave it to you electrical geniuses to tell me that. Any Idea where I should start troubleshooting this? No Idea where the reverse switch is in the manual trans.
 

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Ok I wanted this to go into Electrical but getting frustrated after looking for an hour and not finding a way to post in Electrical. So here it is...
I'm looking for some advice on my reverse lights and backup radar thing. I have an '07 with the manual trans. The backup radar thing was the 1st to go. maybe a couple of years ago. It now just gives a long beep at the beginning and short beeps while the truck is in reverse. No radar Geiger Counter that your coming close to anything anymore but I was ok with that.Kinda don't need it anyway. Maybe 6 months ago I decided my reverse lights weren't bright enough so I go a pair of LED's from Diode Dynamics. But now they're dim too. Thinking It's a bad connection or a bad ground? I don't think the radar and dim lights are related but I'll leave it to you electrical geniuses to tell me that. Any Idea where I should start troubleshooting this? No Idea where the reverse switch is in the manual trans.
Back-up light switch is on the RH side of the transmission's front case.

For the dim reverse lights, first thing I'd look for is tarnished, corroded or deformed contacts in the reverse light sockets.
 

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Discussion Starter #3
Back-up light switch is on the RH side of the transmission's front case.

For the dim reverse lights, first thing I'd look for is tarnished, corroded or deformed contacts in the reverse light sockets.
Thanks FJtest!!! I'll try the sockets 1st. Do you know what colors the wires are for the switch?
 

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"why are the wire colors important?"

It is true the switch doesn't care which one is which, but in the harness, the different colors indicate that each wire goes to a different thing (in this case, one is power supply from the battery, and the other goes to the lamp, and from that, a grey/black wire goes to ground).

With a modern automotive harness there are so many hundreds of wires that it becomes hard to do but each unique color combination is electrically the same wire, no matter where you find it in the harness. The good thing about that is you know that anywhere you find a wire with that exact color combination, you could tap into it and get the same result as if you had connected at its source.

This is true for the heavy wires carrying +12V power to things. The really skinny "signal" wires are sometimes carrying digitized CAN, or LIN messages and tapping into one of them could really mess things up. :)


Norm
 

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"why are the wire colors important?"

It is true the switch doesn't care which one is which, but in the harness, the different colors indicate that each wire goes to a different thing (in this case, one is power supply from the battery, and the other goes to the lamp, and from that, a grey/black wire goes to ground).

With a modern automotive harness there are so many hundreds of wires that it becomes hard to do but e color combination is electrically the same wire, no matter where you find it in the harness. The good thing about that is you know that anywhere you find a wire with that exact color combination, you could tap into it and get the same result as if you had connected at its source.

This is true for the heavy wires carrying +12V power to things. The really skinny "signal" wires are sometimes carrying digitized CAN, or LIN messages and tapping into one of them could really mess things up. :)Norm
Norm -

I think you mis-understood my question to the OP ("why are wire colors important?").

The question was asked specifically in the context of the OP's problem with his reverse lights, which is most likely caused by either by high-resistance at the bulb sockets, high resistance within the reverse switch or its connector, or a corroded ground connection. Since there IS B+ present at the LEDs, I wouldn't spend time looking for hard defects in the wiring harness (open circuit or dead short), but look for sources of resistance at connections instead.

Obviously, understanding the color coding of each wire is absolutely essential when you are tracing some electrical system fault through the entire vehicle schematic. I don't think that is what the OP needs to do, at least not initially.

You need to be particularly careful with Toyota's schematics, where two different options may be shown in the same schematic, with each option identified only by an asterisk or a small numeral. In the '07 wiring diagrams, in the reverse light section, both the manual transmission circuit and the automatic transmission circuits are shown in parallel. In the headlight section, the wiring for DRL and non-DRL options are shown, which are quite different.
 

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Good input FJTest, thank you for pointing that out.
(also, I probably should have asked, first, if yours had been a rhetorical question because I was pretty sure you knew the reason why the colors are different!).

:)
 

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Discussion Starter #8
Yellow with red stripe and red with blue stripe.
But why are the wire colors important?

(Schematic clickable for larger image.)
Just figured It's a positive way of identifying that I found the proper switch if that winds up being the issue? And thanks for the schematic!
 

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Let us know what you find - my reverse lights flicker and die... Also on LEDs... Maybe the voltage isn't high enough on that circuit to drive them? something that I should check myself.

You can test the reverse lights yourself - just put the transfer case into neutral and the trans into reverse and you're golden - even with the engine running ;-)
 

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Let us know what you find - my reverse lights flicker and die... Also on LEDs... Maybe the voltage isn't high enough on that circuit to drive them? something that I should check myself.

You can test the reverse lights yourself - just put the transfer case into neutral and the trans into reverse and you're golden - even with the engine running ;-)
One problem I've seen with the cheaper LED lamps is the mechanical fit of the contacts into the socket, and the subtle details of the electrical interface.

The OEM incandescent bulbs are (obviously) glass, and the leads pass through the base of the bulb and are formed around the bulb base. The thickness of the glass and the diameter of the leadwires are tightly controlled, and there is only "line" contact between the leadwires and the spring contacts in the socket. This creates a high contact force between the leadwires and the spring contacts, promoting low electrical resistance and high mechanical "grip" of the bulb.

The cheaper LED lamps just use a piece of printed circuit board material with areas of copper exposed (hopefully gold plated). The thickness of the board material may not closely match the specifications of the OEM glass bulb, and because there is a relatively large contact surface between the circuit board and the socket, the "clamping force" per unit area of the electrical contact area is much lower than in the OEM bulb with its small leadwires. The result is potentially higher electrical resistance and particularly susceptibility to corrosion from moisture, etc.

The better LED lamps replicate the base of the OEM incandescent bulbs.

Below:
(Top) Poor quality LED lamp with electrical contacts formed by copper PCB material
(Left) OEM incandescent bulb with leadwires formed directly over glass seal area.
(Right) Better quality LED lamp with leadwires similar to OEM glass bulbs
 

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Thanks FJtest - been trying to get my son to understand about dirty terminals and connections. He just had this issue in his TJ, which he swapped everything for LED, but went cheap...
 

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One problem I've seen with the cheaper LED lamps is the mechanical fit of the contacts into the socket, and the subtle details of the electrical interface.

The OEM incandescent bulbs are (obviously) glass, and the leads pass through the base of the bulb and are formed around the bulb base. The thickness of the glass and the diameter of the leadwires are tightly controlled, and there is only "line" contact between the leadwires and the spring contacts in the socket. This creates a high contact force between the leadwires and the spring contacts, promoting low electrical resistance and high mechanical "grip" of the bulb.

The cheaper LED lamps just use a piece of printed circuit board material with areas of copper exposed (hopefully gold plated). The thickness of the board material may not closely match the specifications of the OEM glass bulb, and because there is a relatively large contact surface between the circuit board and the socket, the "clamping force" per unit area of the electrical contact area is much lower than in the OEM bulb with its small leadwires. The result is potentially higher electrical resistance and particularly susceptibility to corrosion from moisture, etc.

The better LED lamps replicate the base of the OEM incandescent bulbs.

Below:
(Top) Poor quality LED lamp with electrical contacts formed by copper PCB material
(Left) OEM incandescent bulb with leadwires formed directly over glass seal area.
(Right) Better quality LED lamp with leadwires similar to OEM glass bulbs
Thanks - I'll check, but I had the same issues with both cheap and expensive (diode dynamics) bulbs. Both flickering the same so suspecting the earth... but I'd assume that the earth is different for each side... hmmm.... maybe try the incandescent bulbs to rule that out...
 

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Discussion Starter #13 (Edited)
Here's an update to my original post. I noticed that this past week I had NO reverse lights. So I dug through my bulb selection just to get some sort of backup light. I decided due to easier access to try the passenger side light 1st. I found a regular bulb that fit think It's actually an indicator or dash light and plugged it in. What surprised me was the incandescent light wasn't real bright but was on. My drivers side LED reverse was on full Brightness!!! Odd that they're somehow connected like a Christmas tree lights? (One goes out they all go out Lol!) Also while playing with the incandescent light I noticed it affected the rear beeper sound which I had mentioned earlier no longer does the radar thing. Just steady short beeps. That's as far as I got with it so far. But thanks again FJ Test for mentioning to check the bulbs 1st. Saved me a lot of time!!!
 

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Here's an update to my original post. I noticed that this past week I had NO reverse lights. So I dug through my bulb selection just to get some sort of backup light. I decided due to easier access to try the passenger side light 1st. I found a regular bulb that fit think It's actually an indicator or dash light and plugged it in. What surprised me was the incandescent light wasn't real bright but was on. My drivers side LED reverse was on full Brightness!!! Odd that they're somehow connected like a Christmas tree lights? (One goes out they all go out Lol!) Also while playing with the incandescent light I noticed it affected the rear beeper sound which I had mentioned earlier no longer does the radar thing. Just steady short beeps. That's as far as I got with it so far. But thanks again FJ Test for mentioning to check the bulbs 1st. Saved me a lot of time!!!
I have been chasing the same issue in my 07 MT. I finally would up replacing the switch. That worked great for about a month, now it back to flickering at half brightness. I'm suspecting/ hoping the aftermarket (autozone) switch is a pos, and that a new OEM switch is the fix. But I don't hold a lot of faith.. Might just grab the circuit in the trough near the door and run new wire and ground.. Hell IDK.:frown
 

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OP the name of this sub discussion forum is : Stereo / Electronics / Electrical , there is no Electrical section...
 

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Make sure your grounds are good for the taillight assembly, really weird things can happen if the ground is weak.
 

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The reverse switch failed on my 07 6MT and caused the reverse lights to flicker as well. Takes 5 minutes and about $25 to replace the switch. It's on the passenger side on the transmission. Been well over a year with no issues. If I recall, I sent my defective switch to @FJtest to study.
 

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The reverse switch failed on my 07 6MT and caused the reverse lights to flicker as well. Takes 5 minutes and about $25 to replace the switch. It's on the passenger side on the transmission. Been well over a year with no issues. If I recall, I sent my defective switch to @FJtest to study.
Here are some photos of the interior of VDB's reverse switch. Internally it is identical to the Low Range switch that I previously performed a failure analysis on. Failure was caused by oil-contaminated and arc-burned internal contacts, with the moving brass contact totally blackened by tarnish. In both switches, gear oil had gotten past the rubber diaphragm that is supposed to separate the oil-side from the electrical side, and contaminated the contacts.

1. First is a photo pf the switch internals with the moving contact plate in place, on top of the stationary contacts.
2. Second photo is of the stationary contacts in the housing.
3. Third photo is a close-up of the badly eroded stationary contact.
4. Fourth photo is the badly tarnished moving contact; it should be bright, clean brass on both sides. The more severe tarnish on the contact side may have been caused by the arcing vaporizing the gear oil and releasing sulfur compounds that accelerated the tarnishing.
5. Fifth photo is a Low Range switch on the left, and the Reverse switch on the right.

(The full failure analysis showing all the internal parts of these switches is here:
https://www.fjcruiserforums.com/forums/transmissions-transfer-cases-traction-aids/432729-failure-analysis-failed-transfer-case-switch-non-operational-rear-diff-lock.html)

CAUTION! Since this switch directly carries all backup lamp current (no relay), be very careful about adding any supplementary backup lights without controlling them via a relay, and make sure that the relay coil has some kind of an integral spike-supressor (diode, capacitor, resistor) to minimize arcing at the switch contacts.
 

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