While I was waiting for my new radiator, from LMC truck,for my 64 F-100. I removed the battery, and battery tray. I cleaned and painted the battery tray. When I reinstalled the battery, instead of grounding the battery to one of the tray mounting bolts as previous, I installed a longer ground to one of the starter motor mounting bolts. Everything seemed to be OK. This evening when driving home I turned on the head lights, they did not come on. I checked things out at home, turn signals work, tail lights work, dash lights work, parking lights work, but head lights do not. Is this because of changing my ground from cab to starter? Should I go back to the cab ground? or should I add some grounding straps between the engine, frame and cab? Is there any other problem that may be occurring? Any suggestions would be appreciated.

Thanks,

Denny

 

Hi Denny, first and foremost, welcome to FTE. Found majority of electrical problems was due to poor ground, particularly after painting engine block, engine compartment, and frame. Have a 65 F100 and grounded the batt. connection to the engine block. Found a treaded junction that was not being used, would think the started mount bolts would work. Also check the ground wires for the headlight harness. Suggest clean surface of any dirt, paint, etc. Used wire wheel, or sand paper and cleaned all ground wire connections and added dab of dialectric grease, including harness connections. Also added ground strap between the plastic instrument cluster on C/C to under side of dash. See if the problem is in both lo and high beam position. Only other component I can think of is the headlight switch, shot of electrical cleaner may dislodge any dirt, etc. that may have accumulated on contacts. Perhaps other members will have additional suggestions. For info purposes, in the 'article/specs' forum there is an interesting article on brightening the headlights, the low beam on 65 is very weak been meaning to check out article myself but have not gotten around to it.

 

I would think that the battery should be grounded to the engine block as on just about everything else that I have worked on. Some negative battery cables have a second smaller cable that goes to the body, I prefer a cable from the rear of the engine to the firewall. I believe each headlight has a ground connection which is hooked to the radiator support. check these. (When you see a vehichle with one bright and one dim headlight is usually because the dim headlight has a bad ground). Make sure the radiator support is grounded to the rest of the body if this is where your headlights are grounded. Check your connections to the headlights as you might have accidently pulled a plug apart when you replaced the radiator. I believe the head lights have a circuit breaker built into the headlight switch.

 

I want to try to show how little I know about it. The complete vehicle is an electrical field. You can ground anywhere between the bumpers (front and rear) and all electrical item will work. The largest out going cable is to the starter so the ground is on the engine block. Newer vehicles have ground straps all over but the older just had one.

If some of your items are working you have ground, period. Remove the ground and everything stops. Lights not working is likely because of low or no ground. Perhaps the ground wire attachment are got new paint, and the new paint is stopping the ground from taking place.

There is an excellent electrical tester that looks like an ice pick with a light in the clear handle and a wire with and alligator clip coming out. Find a good place to connect the A-clip and you can test anything electrical on a vehicle.

That is about I don't know about the subject,


John

 

Thanks everybody for your input. I checked all the wiring under the hood for continuity, that all checks out. I regronded the battery back to the firewall, still no headlights.
One thing of interest though, the dash light indicates the high beams are lit, and using the high beam switch on the floor doesn't have any effect, the dash light always show high beams on. I removed the highbeam switch, it seems to sound normal, I checked the continuity on both the high and low beam positions. they are normal. I can't write of the high beam switch as being the culpert, I haven't checked the head light switch out thourghly yet, but all the fuses look OK.
I don't really know where to go from here. (Sigh)

Denny

 

Check for power at the headlamp plug. You could have two toasted bulbs.
Also, there is supposed to be a ground strap somewhere between the engine and the firewall (which has nothing to do with the headlamp problem). Battery should be grounded to the engine block.

 

Wow! now I feel like a dork, special thanks to "60F100" for reminding me to check the grounding on the lights after the radiator istall. I checked, one I missed the ground connection totally, and on the other side I connected the ground, but, the wire had broken further down and I didn't notice it. Thanks for all your suggestions and help. Everything is working perfectly now.

Denny

 

Nice. Sometimes it's just something you overlooked.