Why is it every ford truck I have had that is older than my 92 has gremlins in the headlights. I just brought home a new to me 78 4x4 camper special. I tried all the lights out before I bought it. I got it home and when I turn on the head lights the blinkers blink VERY slow. Then I hit the brakes and they quit blinking altogether! What gives? Is this a flasher issue? Do I need to chase down old dirty grounds and install relays and all that crap?

The right side turn indicator in the instrument cluster is out, does this mean anything?

TIA Todd

 

It's a ground issue. Check the grounds where the pigtails meet the radiator support, and check to make sure there's a ground strap from the firewall to the engine block. Check where the tail lights ground to the bed, and make sure there's a ground strap from the cab to the frame (this combined with the aforementioned ground strap are essentially what ground the bed). Check the sockets as well; often times you'll lose ground in the sockets themselves (seems to be pretty common with tail lights).

The turn signal flashers used in these trucks are called thermal flashers. The speed at which they flash is completely dependant on the load placed on the flasher (because that determines the amount of current through the heating element in the flasher). That's why sometimes you see people at stop lights with really fast turn signals; they either have a turn signal out, used the wrong bulb, etc. You have a ground problem, which is caused by a ground shift, which itself is caused by resistance in your ground path. Higher resistance means less current, which means a slower flashing speed. That's why your two symptoms often go hand-in-hand.

Do fix the turn signal indicator in the dash, because it's part of the load on the flasher. But it's not part of the ground issue.

It sounds like you have a pretty good idea of what the problem is; but I'm sorry to say you're right, you just have to go through and check everything (that's helpful isn't it ) One suggestion I have is to do this with a multimeter, because it will let you compare the battery voltage with the voltage seen at each socket. That will give you a quantitative idea of how much voltage you're dropping in your wiring harness. Just be careful not to short the socket termianls with your meter probes, because some of those sockets are a tight fit.

 

78 4x4 camper special I fixed the turn/brake problem, and when I did the right turn indicator started working. All the faults of PO poorboy trailer plug on the rear bumper.

I noticed that I had a starter solenoid problem. I think it is somehow related to the auto shift lever? What gives here? I have never owned a truck with an auto, so I am in virgin territory here.

The darn headlights go out on bright after about 2 minutes and leave me in the dark. I had the same problem on my 66 and added relays. That worked for awhile and now on the 66 the low beams go out when I dim down from highbeams. I am reluctant to do the same deal on the 78 cause I didnt really fix anything on the 66. Also in 78, the low beams went out too about 20 minutes after the highbeams went out. The dash light went out too, but the headlights were not effected. This is scary and not safe! What is the real way to fix this problem. Please help!!!

TIA Todd

 

What's wrong with the starter solenoid? If you don't tell us what's wrong (truck not starting, solenoid staying engaged, etc) then we can't figure out what to tell you.

Are you saying the headlights go out, but come back eventually?

 

The lights going out after a few minutes would make me think that the headlight switch is going out. Had the same problem with my pickup,a new switch,the relay upgrade,and a set of foglights (just in case!) took care of my problems.

Something else to check is the headlight plugs themselves, the wires can come loose from the actual plug itself causing problems...hope this helps.

 

Sorry?! When I turn the key sometimes the solenoid just clicks like a dead battery, sometimes it makes no noise at all like there is no battery. Sometimes it fires right off just as it should. It does not matter if the engine is hot or cold. It is seamingly entirely random. When any of the first 2 conditions happen it seems to help if I wiggle the column shifter a bit. I did try to start the truck in forward and reverse gears and It would not start. I know that is by design. I was able to create the same conditions in neutral and park. Each position acted the same way with a wiggle of the shifter in a no start condition. That leads me to think there is something punky with the NSS or something in the column.

When on high beam the headlights go dead after a short time of use. When I hit the dimmer switch and push in then pull out the headlight switch the low beams came back on. After 20 minutes of continuous use the dash lights went out, but the low beams remained on. About 1 minute later the dash lights came back. I did try to dim the dash lights and then brighten them with the headlight switch, but it did not seem to do anything. About 10 minutes later the low beams went out and I did the push pull deal again with the headlight switch. It is dark after dark at 55 MPH!

HTH

Todd

 

Check you headlights to see if they aren't high powered (wattage) halogens or something.

Josh

 

I know this sounds really stupid, but I got to ask. How?

Todd

 

You'll need to pull the lights and the watts should be stamped on the rear. I might be wrong, but stock is around 35 or 45 watts for low and 55 watts for high.

It is appealing to throw in some 65/90 or even 90/100 watt lights to help brighten the road, but all it does is trip the breaker in the light switch.

Josh

 

That sounds really easy. I guess I didnt know that there were choices when I go to the parts house and tell them I need a new headlight? Do they stock multiple watt rated lamps in the same shape/configuration? Are we forced to modernize to the later standards even with old iron?

Todd

 

There are a ton of lighting options... it is the newer Hi Output Halogen bulbs that are causing problems...

However, I firmly believe in adapting Headlight relays to power the headlights. Once that is accomplished you can run the modern hi-output lights no problem and the headlight switch becomes just a switch, rather than a switch and circuit breaker.

Josh

 

Okay, I pulled the bulbs and on the back in black was stamped 65/35 Watt. So I think this within reason from what you are describing. When I pulled the headlight I was able to find the groun d for each headlight. I cleaned them and sanded down to bare metal the core support where the screw goes into it. Just for good measure I added a ground wire from the - term. on the battery to the core support with a shiny spot to screw to. I ran the high beams for 25 minutes and they stayed on. The wires at the dimmer switch were a bit warm and the head light switch was warmer. Is this normal?

Also wondering how to go about getting the clearance lights on the top of the cab to come back to life.

Todd

 

Nice, headlights are good and grounds are now good.

As for the clearance lights, you'll need to pull the headliner and trace from there.

Josh