Been running into problems with no instrument panel lights, no tailights, no front side marker lights and no cab/roof lights. All my fuses and bulbs are good. From my brief searching, I'm seeing the headlight switch come up as a possible culprit. Anyone knowledgeable on this? Also, I "cut the headlight switch out of another truck the same year (1980). It's got those rubber knows and I can't figure how to get the **** off of the shaft. I got my **** off of my truck by pushing in on the slot. But this rubber **** has no holes or slots. Should I spray it with WD40 and pull?

Never mind. I found a nib to depress so the entire shaft comes out.

 

Well, after wiggling the entire switch around a bit, all the lights are now working. Not sure if it's a loose ground wire or what. I'll have to check it out tomorrow.

 

The connector is notorious for overheating. You can buy a plug with a pigtail to repair it. Also check the tan/white wire. It's what feeds the power to the switch for the running lights, and is known to melt and burn out. There is a separate power feed to the switch for the headlights.

And as the connector overheats, it also ruins the switch.

 

My truck was doing something similar. When I would be driving at night, the headlights would flicker, go off completely then come back on. I replaced the headlight and high beam switches about 3 yrs ago, and it's been a lawn ornament for 2 yrs now. I had it on the road for about 6 months last yr when this started happening.

I have tried wiggling wires and adjusting wires and sometimes they come on and other times they don't. Could this be a switch related problem, too?

 

Good thing the switch(es) are easy to get to (although I haven't pulled the plastic panel off yet). What a pain to have to replace the switch in some of these new cars.

 

Be aware the 1980 switch is a one-year wonder, and it is wired differently than 1981 and newer trucks. There is no Tan/White wire on the 1980.

The 1980 is more prone to overheating of the switch and wire harness damage.

1980 Headlamp switch: E0TZ-11654-A

1981-1986 Headlamp Switch: E1TZ-11654-A

1959-1991 Dimmer switch: B9AZ-13532-A

Part numbers may be out of date or obsolete.

 

The headlamp switches circut breaker is triggering. This is because there may be a wiring fault, a problem with the dimmer switch on the floor, or the headlamp switch itself. If you replaced the Headlamp and dimmer switch with known good parts. (don't buy chinese as they are known to be defective out of the box) If you replaced the parts, it has to be a wiring fault. Check for corosion at the connectors. Check the headlamp connectors, and check the ground wires to the dash and to the headlamp connectors. Make sure they are clean and tight. Corosion can cause resistance in the circut, which will trigger the circut breaker. Also check the Tan/White wire franklin mentioned if you own a 1981-1986.

Mine has done the flickering light syndrome three times in 30 years and it was caused by three different things.

1) Defective Headlamp switch (replaced with motorcraft)
2) condensation (Fog and rain was getting the headlamp connectors wet creating a short circut. Packed connectors with dielectric Bulb grease.
3) Defective dimmer switch. Connections at the switch were corroded due to wet feet.

 

Took the headlamp switch out today and checked the connection/prongs for corrosion. None that I could see. Slipped connector back together, reinstalled dash panel. Lights worked. I really thought that did it. A little while later, pulled the switch on- no lights (as mentioned above- cab lights, taillights, instrument panel lights). Pulled connector to one of the headlights and wiped the terminals clean (of grease). Plugged it back in- the lights all worked. I thought that did it. Later- no lights. Just got behind the dash and wiggled the wires around on the headlamp switch. Pulled it on and all the lights worked again. I'm sure they won't work once I go out again. I did notice that the switch I pulled on my old 1980 Ford Custom had a ground wire connected to the switch body (unfortunately, this switch won't fit my F-150). No such ground wire on my switch. Not sure what to make of that. Not sure where to go from here. I checked the foot switch for high beams. No corrosion there. I can get a new switch sent for $50 plus shipping. But I'm still wondering if it's the switch. Haven't been able to check the entire run of wire for any shorting yet.

 

Went out and had another go at it. I can consistently wiggle some of the wires on the pigtail part of the connector (the plastic part that plugs into the switch) and get the lights to come on. I kept the lights on for about 20 minutes and the switch connector is slightly warm to the touch. Is that normal?

 

Took the truck out for a good ride. The lights stayed on. When I reached behind to feel the switch after shutting down, the switch was quite warm- much warmer than before. The metal part of the switch was almost hot. From a bit of searching, it sounds like some of the older vehicles have had such problems, requiring that a relay be installed for the headlights. I think the switch warmed up tonight because I drove it with the headlights on. I'll have to take it apart again tomorrow and see if I can clean it up and check the wires more carefully. If that doesn't do it, then I'm not sure what approach to take.

 

I had basically the same problem with my 1981 F100 earlier this year. I replaced the
headlight switch with a new Motorcraft switch and it corrected the problem.

 

Can't get Motorcraft switches here, at least in this part of Canada- obsolete. Was talking to a friend who knows a bit more about these things. He says there must be a short somewhere around that switch connector. Also says to put grease in there. What sort of grease are we talking about? I can get a tiny tube of the stuff but is there other grease that will do? By the way, I wiggled the wires around this morning with no success. Lights not working. As well as horn. The horn must be connected to this circuit.

 

Dielectric grease ( http://www.permatex.com/products/aut...-Up_Grease.htm ) is what your friend is talking about.
Dielectric grease is a non-conductive, silicone grease designed to seal out moisture and, therefore, prevent corrosion on electrical connectors. Being non-conductive, it does not enhance the flow of electrical current. This property makes it an ideal lubricant and sealant for the rubber portions of electrical connectors.

Dielectric grease is typically a translucent, grey substance that is insoluble in substances such as ethanol, methanol, mineral oil, and water. It is soluble, however, in the industrial solvent methyl ethyl ketone (MEK) and mineral spirit. It is important to note that dielectric grease will melt silicone rubber over time, and thus should not be used on connectors, such as o-rings, that are made of this rubber.
While the indicated use of dielectric grease calls for it to be used only on the non-metal parts of a connection, it has been shown to be effective at preventing corrosion when applied directly to the metal connectors as well. Care should be taken when using it in this way, because this application can, in some instances, cause the connection to stop working. A common reason for such a failure is that the grease has not been pushed entirely out of the way between the two points of contact.

Dielectric grease is most widely used as a sealant for spark plugs, and is applied to the rubber boot of the plug wire. The grease not only helps the boot slide onto the ceramic portion of the plug, but prevents dirt, moisture, sand, and other foreign objects from contaminating the seal, and compromising the electrical current. Dielectric grease is also commonly used on the gaskets of multi-pin connectors in car and marine engines.

It can withstand high temperatures, making it an ideal substance for use in engine compartments and other similar locations. Most standard brands of dielectric grease are rated to 392° F (200° C), and many can operate at up to 500° F (260° C). A typical tube of grease generally sells for around $5 US Dollars (USD) per .33 ounce (9.4 gram) tube.
Aside from sealing spark plugs, dielectric grease is often used to lubricate other engine-related parts, such as rotors, distributor caps, and speedometer cables. It is also employed in many other situations where electrical connections may be exposed to moisture and dirt. These can include outdoor lights, satellite television installations, trailer hitches, and battery terminals.

 

Doesn't seem like the grease should be used on a headlight switch. Might make this diagnosis more difficult if it introduces a new problem. I took everything apart and am checking the connectors. I scraped a bit of thin film off the silver contacts. Hooked the switch up, went on for awhile and then off. Seems like each time I disconnect and reconnect, it works, usually. I kept the headlights on for awhile and I could feel the switch getting warm. I suppose, before trying to find a short in the entire harness/wiring, it would be the easiest to replace the switch and see if that corrects the issue. I wonder, though, what could actually be wrong with the switch.

 

Just called NAPA for a switch. I found the pic of the one they can order. The only thing is that it has an extra connector, as circled in green in the pic in the link below. My switch is missing that particular connector and there's no sign of it having been broken off. If it had broken, there would be a flat spot where it was attached. The round flat copper stud is there but without a prong. The letter "P" resides next to that stud. I checked my block that plugs into the switch and there is an entry there for that particular prong which is missing on my switch. I checked under the dash for any lose wire that may have come out but there is none. As stated earlier, I notice that there is no ground wire for this switch as there is on my 1980 Ford Custom. The letter next to this "missing" prong is "P". Not sure if I should order the switch or not. The number of the switch that I have out of my truck is different than the one than 81-F-150-Explorer member gave (E0TZ-11654-A). Mine is E0TB-11654-AA.
Where do I go from here? The switch is going to cost me $70 by the time it's shipped. It will fit. The extra prong there will slip into my existing block, although I had no wire under the dash to connect to it. Could it possibly be a ground wire?

https://www.ford-trucks.com/forums/p...ictureid=46558