1965 Dim Headlights

[Dick G.]

Good Morning
We drove our twice top-flite 1965 back from a car show last week. The headlights were really dim.
The next morning I started taking battery voltage readings. This car had a body-off by me, finished about 12? years ago and all of the electrical components are that old too. Even the Battery.
This battery is a restoration battery with a gel type battery inside (dry tar top) look. I think I got it from either CC or Paragon.
Its been great.
This corvette has started every time, It's Never failed. I do not drive this car much at all. My Fault.
I keep a battery tender on her most of the time.
Readings across the battery:
Engine off: 12.7v
Engine at idle: 13.2v
Engine at idle with the headlights and Heater blower both on High: 12.8
Engine at 1500rpm with the same above load: 13.2
I tightened the Belt.
I cleaned the battery connections.
I found one loose ground connection at the regulator. removed sanded to bare metal, star washer replaced, reinstalled.
I removed, cleaned, and reinstalled the ground on the radiator support on the left side.
Yesterday, I removed the alternator and took to Oreilly's auto parts and watched them test it. It tested good. I saw a 13.8-14.5 output range on their test device.
I hope to drive this corvette over there today and have them perform a load test on the battery.
Its probably time for a new battery at 12 years old, I may just change her out, but will that fix my initial headlight issue?
Does anyone make a dry/gel type restoration battery anymore?
Any suggestions or troubleshooting ideas appreciated.
Thank You
DG

[Mark E.]

Re: 1965 Dim Headlights

The charging system should maintain 13.5v - 14.5v (or there abouts- check the CSM) with moderate load at idle (e.g. with the headlights on).

As a first step, I suggest a new battery. Your 12 year-old is past its lifecycle. Not only may it give up the ghost at any time, but if it has a weak cell (which is likely with an old battery), it can create an extra load on the charging system and decrease voltage.

Second step: Check voltage at idle with all accessories off, then turn on the headlights. Voltage drop should be nominal.

Third step: If the charging system can't keep up with a new battery, check/clean all connections (including grounds), then test the regulator and alternator.

Let us know what you find.

[Dick G.]

Re: 1965 Dim Headlights

Mark
Thanks for the reply.
Does anyone make a gel-type battery encased in a correct battery enclosure. I can't remember who made mine. I saw they make these top only battery covers. These batteries are a pain to remove. The gel-type alleviate at least one aspect of changing them out. No acid spills.
Thank You

[Leif A.]

Re: 1965 Dim Headlights

Dick,
Silly question here...how often do you drive your '65 at night? Do you have the original type T3 bulbs installed? Reason for my question, those old T3 have the lumen output of a candle compared to todays' modern halogen and LED lights. If you're still running the original T3 bulbs, you might consider installing some "plug and play" halogens from your local auto parts store. (Sylvania H5001 and H5006)

[Bill M.]

Re: 1965 Dim Headlights

Lief / Dick

I was going to ask the same question. When I drive at night it looks like my lights are not even on. I live in the country so extra dark. I was looking for reproduction T 3's at Carlisle but saw none.

Bill

[Richard G.]

Re: 1965 Dim Headlights

Yes Leif is correct the output of the lamps could be the issue.
The reproduction T2 have a higher watt rating and may help.

However, you have proved the potentiality to have the correct voltage at the bulbs but that is all.
Now measure the voltage at the bulb terminals with the lights on and the bulb lit.
That should give you the needed direction, wiring, switching or bulbs.

[Dick G.]

Re: 1965 Dim Headlights

Leif
I have reproduction T3s.
Since I may be buying a new battery, I wonder if I could carefully cut the top of this battery case off and remove the old battery and insert a new battery.
I do not know what gel battery this manufacturer installed. I think they're out of business.
These are not cheap but would also work.
Thank You
.https://www.ecklerscorvette.com/corv...965.html#close

[David M.]

Re: 1965 Dim Headlights

Trace the ground circuits to the headlights. Clean as needed. The pig tails at the headlights could have corrosion. Pull them and look at the terminals and head light tabs. Check the battery neg to frame connection. In fact check all grounds. 12 years is enough time to re-rust good grounds. I always follow cleaned/serviced grounds with battery terminal protectant or clear ignition spray.
You could do a voltage drop test to zero in on the bad spot.

[Leif A.]

Re: 1965 Dim Headlights

Leif
I have reproduction T3s.
Since I may be buying a new battery, I wonder if I could carefully cut the top of this battery case off and remove the old battery and insert a new battery.
I do not know what gel battery this manufacturer installed. I think they're out of business.
These are not cheap but would also work.
Thank You
.https://www.ecklerscorvette.com/corv...965.html#close

Dick,
Re-reading your original post, the battery seems to be OK. Besides, the battery's basic function is just to start your car. Once the car is running, all your accessories (lights included) run off the alternator. I would start by buying a single H5006 (low beam) halogen bulb and insert it in one side of your car. Turn on the lights and compare the old one to the new one...side by side. The bulb is $10 and could save you a lot of time and angst.

[Dick G.]

Re: 1965 Dim Headlights

All good ideas.
Thank You

[Dick G.]

Re: 1965 Dim Headlights

After numerous headlight tests the right side Low Beam T3 failed.
I pulled both low beams out.
Battery was at 12.5v
I then read both low beam headlight sockets.
Both sockets and connections look like new. The sockets read 11.91v
I swapped out the failed T3 bulb with a new Halogen bulb. Way Brighter as previously stated.
Does anyone make a T3 Halogen bulb?
I'm off to do a search.
Thank You

[Leif A.]

Re: 1965 Dim Headlights

After numerous headlight tests the right side Low Beam T3 failed.
I pulled both low beams out.
Battery was at 12.5v
I then read both low beam headlight sockets.
Both sockets and connections look like new. The sockets read 11.91v
I swapped out the failed T3 bulb with a new Halogen bulb. Way Brighter as previously stated.
Does anyone make a T3 Halogen bulb?
I'm off to do a search.
Thank You

The original Guide T3 lamp in your car was a simple sealed beam headlamp...non halogen. The lamps I mentioned above are Halogen and are a direct fit with no modifications or extra accessories needed...simple "plug and play". Available online or at your local FLAPS.

[Joe R.]

Re: 1965 Dim Headlights

Hi Dick,

The 11.91 Vdc you measured at the headlight socket sounds too low to me if you have 12.5 Vdc at the battery. I would look closely at your grounds with a good meter to be sure they are really "ground".

Joe

[Richard G.]

Re: 1965 Dim Headlights

The 11.91 Vdc seems good to me. I am assuming its Headlight post to post at the headlight harness.

Below is another method to do this the headlights on. Top of the battery post to the headlight connector is the volt meter connection.
This will isolate the bad connection (if you have one) to the ground side or the + side of the wire.

We're chasing very small resistances, often smaller than a single ohm. The resistance (ohm) scale on your DMM probably bottoms out at 200 ohms, making measurement of single-digit values tricky. Instead, use the voltage scale, which on most DMMs is accurate down to several millivolts. Let's dig in.Start by turning on the offending circuit--in this case the headlight low beams. Now we'll measure the battery voltage. We need to know the exact number you see when metering across the battery posts. And I mean the lead posts themselves, not the clamps. It should be around 12.5 to 12.8 volts if the battery is fully charged.
Back-probe the connector on the dim headlight. The black lead on your DMM should go to a good ground--preferably to the battery negative post. The voltage you meter at the low-beam lug, as it turns out, is about 11 volts. That's lower than our system voltage at about 12.5--but not low enough to explain the severe dim-out. Now probe the ground lug at the bulb connector. Surprise! The meter reads nearly 4 volts--it should read zero. This indicates a resistance in the ground side of the wiring, leaving only 7 volts for the filament.

'm not happy with more than a few hundred millivolts of drop across any connector. The total drop in any circuit shouldn't be more than 1 volt, whether it's a dome light drawing 500 milliamps or a starter drawing 200A

The issue is the circuit can read 12 volts with no load and only drops when the load is applied. A friend of mine just did this on his fuel pump. Installed a new one as he had 12 volts at the connection at the tank. (the pump was $250) Then it still didn't work. After measuring the voltage with the pump rinning he had 2 volts at the connection. The fix; turned out his grandchild had spilled a coke inside the rig and it had corroded the connection where it goes through the floor. It was fixed for free by bypassing the plug that gm put there to make it easy to assemble the rig.

This is just an information post at it appears you may have isolated the problem to the bulbs.

[Darryl D.]

Re: 1965 Dim Headlights

From the corvetteforum on this subject.

http://www.madelectrical.com/electricaltech/brighter-headlights.shtml