dim headlights

[gonzo72 10]

I have a 1947 Ford V8 restored in 2003 ( including a new wiring harness). It is still a 6 volt pos grd system. The headlamps appear to be "new". They are VERY dim, so much so, that I can barely see the road in front of me. The gen has been tested and is puitting out 6.5 volts. The volt reg and battery have also been tested and found to be good. I have installed new battery cables. I removed the headlamps and inspected the three prongs and the sockets for them...OK-clean. I removed the grd wire from each, sanded the ends of the contacts and the area around the hole in the buckets to bare metal and reattached the wires...no difference. The dash lights also do not work..rheostat under dash appears to be new...nothing happens when I turn it Bulbs are all OK. HELP!

[MCHinson 2,735]

Welcome to the AACA Discussion Forum.

Are the new battery cables the correct cables for 6 volts or are they standard off the shelf auto parts store cables? If they are off the shelf cables, they are designed for 12 volts and will not flow current sufficient for the 6 volt system. Does the starter turn a bit slow also? I would also suggest that you check all ground wires on the car. The ground connection at the engine block would be a good place to check for a ground issue.

[West Peterson 452]

My thoughts also. Many problems with 6-volt systems can be traced to 12-volt cables installed where 6-volt cables need to be.

[R W Burgess 246]

Test the light grounds by running a ground cable from the battery (it can be a small wire)directly to the bulbs in question, then work backwards, body ground, frame ground till you find the culprit.

Wayne

[Fr Mike 1]

In addition to what has already been said about really heavy battery cables with your negative cable being attached to the starter etc, and positive cable attached to the frame, ground straps are sometimes needed (especially when the engine and body are mounted to the frame on rubber), connecting engine block/ frame/body. Adding a 6 volt headlight relay will not only prolong the life of the light switch but also will increase further the brightness of the headlights. And if the reflectors are re-plated by UVIRA (uvira@terragon.com) & halogen plug-in bulbs used, the final result oif all this will be lights as bright as or brighter than sealed beam lights . . . without need to re-wire and no additional drain on the battery.

Edited August 23, 2010 by Fr Mike (see edit history)

[mrspeedyt 28]

this may sound stupid.... but it is possible that the bulbs may be 12v units...

[gonzo72 10]

I replaced both cables with the correct ones from MAC's

[DavidAU 35]

Make sure you have ALL the earth (ground) straps in place. As a minimum, you need the one from the battery to a bell housing bolt near the starter. One from a rear cylinder head nut/stud to the stud on the firewall under the battery box and another from the same stud down onto the frame.

David

1923 Metallurgique Torpedo

1931 Rolls Royce Phantom 2 Continental

1940 Ford Deluxe Coupe

1947 Mercury Coupe

[gonzo72 10]

NOPE! Like new Wagner 6 volt, and they test good (bright) with jumpers from battery..

[elmo39 1]

if thats the case you have a grounding problem

[Jon37 62]

How about the light switch itself? Have you tried bypassing it with with a jumper wire, to see if the lights work better then? Could be corrosion in the switch. I myself have installed a (non original) relay behind the dash, so the dash switch (and the floor dimmer switch) only give a "signal" to the relay. The power runs from the battery to the relay and then directly to the headlights without having to travel through miles of questionable wiring and possibly defective switches.

[billybird 10]

Try this: take off the headlight rims and run a test lead from one headlight ground directly to the other one with the lights on. If the lights brighten, you know there is a ground problem. After working on early V-8 Fords for the last 25 years I have seen bad grounds do crazy things.