Intermittent Fog Lights ?

[davem]

My daughter has our 2001 XLT 4x4 V-6 SOHC (181,000 miles) at college, but I got a chance to drive it when she was home over Thanksgiving.

In Low-beam mode, I tried turning on the fog lights, but neither the fog light indicator on the dash, nor the fog lights themselves came on. Later after toggling between high and low beam mode, the fog lights worked normally (might have been an ignition cycle off/on in there too). But after going to high beam again and back to low beam, the fog lights and indicator did not work.

My daughter usually has the fogs on and never reported an issue, but I dont think she uses the hi beams much, if at all.


I assume the multi-function stalk (turn signals, hi/low beam, wipers) is the issue ? Thinks its still in hi beam ?

How do I diagnose this ?

 

[koda2000]

With the fog light switch ON, the fog lights are supposed to go off when you have the high beams on, but they stay on when the low beams are on, so I'm thinking multi-function switch issue, as the problem is intermittent. If it's not the MF switch it might be be fog light relay is flaky. I think the relay is located in a box under the air filter box. I know there are several relays there, but IDK if the fog light relay is one of them, but I seem to remember that it is.

 

[davem]

With the fog light switch ON, the fog lights are supposed to go off when you have the high beams on, but they stay on when the low beams are on, so I'm thinking multi-function switch issue, as the problem is intermittent. If it's not the MF switch it might be be fog light relay is flaky. I think the relay is located in a box under the air filter box. I know there are several relays there, but IDK if the fog light relay is one of them.

Hmmmmmmmm, I just replaced the air filter the day before ........ maybe something I did caused a bad connection under there ??? (the air filter housing does require a little 'jostling' to come apart/re-assemble)


Is replacing the MF switch a big job ?

 

[96Green]

If it's not the MF switch it might be be fog light relay is flaky. I think the relay is located in a box under the air filter box. I know there are several relays there, but IDK if the fog light relay is one of them.

The fog light relay IS one of those. I don't recall which one, though. Pretty sure it's one of the smaller ones.

If it really is that randomly intermittent, I might suspect the relay is sticking.