Headlights WON'T listen

[HazeDrake]

Hey everyone, Haze here with his 95 stang.

Anyways, the other week I wired up my own fogs using a 30a relay, and they worked fine. But the other day while driving I noticed my lights (headlights + fogs) were flickering on and off - but I wasn't touching the switch. Later, my fogs must of got hot since the glass around them blew up. So, I bought a new (and better) relay, new bulbs etc... wired it up and working. But it did it again - so, I disconnected the relay (which wa smakin wierd noises), so my fogs aren't connected at all, and...

my headlights were flickering on and off even though the fogs were completely disc. Meaning my fogs were only flickering in the first place since my heads were. The question is, WHY ARE THEY DOING IT? Any ideas? It's not one headlight either, both do it at the same time.

 

[HISSIN50]

More info on what has been done wiring-wise please (Cliff notes are good). If you start blowing bulbs (which can take out switches in the process), how is your car's voltage. An alternator voltage regulator on the edge of dropping a duece can allow high system voltage (15+ volts). This can blow out bulbs.

You have a fog light relay socket in the underhood fuse box - I suppose you could have used that if you had desired.

What is the source for the fog lights being able to turn on (what's the power source to your fog light switch)?

It's not uncommon for the headlight switch connector (not the switch necessarily, but the plastic connector that the switch plugs into) to overheat and cause issues.

One question for the 94-95 guys: On foxes, there's a thermal switch in the headlight switch (it's like the thermal switch on your hairdryer). Do 94-95's have one as well? On a fox, flickering headlights would mean the circuit is overdrawn and the switch is tripping. After the lights are off for a bit and the thermal switch cools and the contacts reconnect, the lights come back on.

Good luck.

 

[HazeDrake]

Ok, I independantly wired the fogs - both connected to ground, then the + on them goin to a relay (one i bought and added under the hood - not in the fuse box). The headlight low beam and high beam wire both also go to the relay and act as a switch. the other two relay prongs are connected to the battery. It is a 12v 30a relay.

As of right now, i disconnected the ground from the relay so my fogs wont bother anythin, but my headlights are still acting wierd, flickering on and off.

Also, since when I drive the flickering won't start when I first drive the vehicle so my guess is something is heating up then cooling, hence the flickering. I dunno what to do to fix it.

 

[HISSIN50]

How did you wire the relay exactly? How did you manage to run the low and high beams to the relay (terminal 86 most likely) without having backfeed issues? Did you use a diode? Otherwise, I can see an issue where anytime either lows or highs are on, you're actually energizing both lows and highs at once. That could heat things up a bit.

For simplicity, I'd have wired the fogs up to the parking lights (if that's legal in your locale - it is NOT in many places. If not, a switch for the fogs is needed). Wiring it to the parking lights means that anytime the parking lights are on (including with lows and highs), the fogs are on.

And otherwise, the relay should only have one wire going to the battery (the common terminal, normally 30).

Am I way off base with how it was wired up?

Good luck.

 

[HazeDrake]

Hey Hissen, thanks for the reply, here is an exact diagram of how I wired up my fogs to the relay.
http://3.8mustang.com/forum/attachment.php?attachmentid=70340&stc=1
Also, the poeple on that forum were saying that since the car is fitted with the OEM wiring for fogs, all I need is to buy a switch. But I would prefer switchless - either way I have to fix my lights cuz I cant drive at night with them flickering.

 

[HISSIN50]

Has someone on that site used that configuration? From what I can see, that's horrible. You can see that the wire for 86 is now connecting high and low beams (since both are connected together via that wire).

There should have been blocking diodes installed with that kind of set-up. Can you kinda see what I mean? WHen the lows beams are on, the power goes to the 86 wire, but it also goes into the high beam wiring. That's what I was afraid of and I dont see how this can work when wired as it is.

MHO. Good luck.

 

[HazeDrake]

It does work... only for a short while until it starts flickering - I'm going to disconnect the high beam connection and see how it works out.

 

[HISSIN50]

I'm not saying the lights wont work.

Let me ask: So you only have either high or low beams on, when you turn on the headlights? Both should be on if it's wired up like that. And if both highs and lows are on simultaneously, that can cause just the issue your having.

Good luck.

 

[HazeDrake]

Yea I understand what you're saying, now that I look at the diagram it really doesn't make much sense, does it. I think I have a few diodes laying around, If I knew the voltage / current goin through those wires i could correct it... but for now im gonna disc the high beam wire. I'll let you know how it turns out!

 

[rockin_rick]

Have you checked your headlight switch? I'd bet that you ruined it or the connector that plugs into it when you wired it up like this. When you have the lights on low, you are pulling all the current for both the lows and the highs through the switch. (In just normal use) it is very common for our cars to have the switch go bad, and take out (meaning melt) the connector that plugs into it, thus causing intermittent connection and flickering. Disconnect the shorted low-to-high wiring to the relay, check the switch, and wire it to the parking light or low beam circuit.

Rick