Flickering Fog Lights

[ChildrenOfBodom]

I hate to post threads here without having a really good question, but this time I really am at a loss.

I have a 99 that did not come prewired. I installed some factory fogs just this last week. I wired them exactly as shown here, except I wired them to come on with the parking lights instead of low beams:

Everything works just fine. I used an OEM toyota switch and everything.

Fogs are grounded to where the bumper and bracket meet. The relay is under the kick panel and is grounded to an existing ground location, where 2 brown wires were already connected.

Now, I just noticed something. In a hard turn, over bumps, or even shaking the car, they flicker. They don't get dimmer, but brighter. It seems clear that they should be of the brighter light outputs.

I parked the truck in front of a wall with the lights on and fiddled with every single connection I made, to no avail. I then try and jump up and down on the slider and they flicker some more.

I don't know what else to do. I will provide any information needed for any help to fixing this issue.

Also, since their install, I had a problem where the switch would literally engage the fuel gauge. I flipped the polarity on the bulbs and it seemed to fix the gauge's ability to be controlled via switch, but it's still very unusually high for my typical mileage.

Here's a Youtube video showing such:

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I searched all over the place and Fireball posted a thread on YT regarding his polarity issue, and that's all I could find regarding the subject.

Please, and thank you.

 

[NickF]

Bypass the relay entirely, and make a quick on/off switch directly hooked up to the battery. See if the problem persists.

 

[ChildrenOfBodom]

I will try this.

Are you suggesting a bad relay?

 

[chad99]

I might be of no help but it really sounds like a grounding issue.

Maybe try putting the ground in a different location?

Or also placing a protection diode across the coil of the relay.

 

[NickF]

It will rule out the possibility of a bad relay, or will prove that the problem lies with the lights themselves or their wiring. Just trying to rule things out.

 

[Dous]

I think if a relay goes it goes, so if they come on and off its probably not the relay.

 

[ChildrenOfBodom]

I might be of no help but it really sounds like a grounding issue.

Maybe try putting the ground in a different location?

Or also placing a protection diode across the coil of the relay.

I have to go out and try the "straight to the battery" method but it is so bright out that I will have to wait til I can tell a difference in brightness. If that works, I'll have to find a better ground than at the bumper mount.

Also, I looked up a Protection diode, I am not quite sure that would aid in the situation I have, but this is my first time hearing about one.

Signal diodes are also used to protect transistors and ICs from the brief high voltage produced when a relay coil is switched off. The diagram shows how a protection diode is connected 'backwards' across the relay coil.

Current flowing through a relay coil creates a magnetic field which collapses suddenly when the current is switched off. The sudden collapse of the magnetic field induces a brief high voltage across the relay coil which is very likely to damage transistors and ICs. The protection diode allows the induced voltage to drive a brief current through the coil (and diode) so the magnetic field dies away quickly rather than instantly. This prevents the induced voltage becoming high enough to cause damage to transistors and ICs.

Thanks for the suggestion.

It will rule out the possibility of a bad relay, or will prove that the problem lies with the lights themselves or their wiring. Just trying to rule things out.

I think if a relay goes it goes, so if they come on and off its probably not the relay.

That is what i figured. A broken relay would just not work... I don't see how that would cause a difference in power reaching the lights.

For the record, the lights do not change brightness with RPM, so I know they are sufficiently powered... unless it is a bad ground...

I would understand if the ground wasn't too good and the brightness was low, but why would it all of a sudden become brighter when shaking the truck? The ground's didn't move... I can't even move them with my hand. They're rock solid.

 

[chad99]

not that im doubting your wire connecting skills but did you solder the connections for the relay/ground or crimp them?...im kind of a freak about connections and prefer to solder but if I had to use connectors (you have to on grounds) I always crimp and solder them.

 

[ChildrenOfBodom]

not that im doubting your wire connecting skills but did you solder the connections for the relay/ground or crimp them?...im kind of a freak about connections and prefer to solder but if I had to use connectors (you have to on grounds) I always crimp and solder them.

I didn't solder... if I get a soldering iron though, I will consider.

 

[ChildrenOfBodom]

I connected a wire and touched on different places for ground. Seems the connection was bad after all. Rerouted the grounds to the little ground just alongside the battery. All is well, even fixed the gas gauge.

Who knew how much a ground could do.

Thanks!

 

[lekiboy]

the thread is a littel old but i just wnat to thank you guys for making this.
it saved me alot of trouble...i just transferred the grounding from the chassis to the body beside the battery and voila, FIXED the flickering!