1970 300 loses electrical power

[Waggy]

When I move to halogen lights, after running with the lights on for a while, the electrical power would stop flowing as if the battery was disconnected. I was told the Halogen lights required too much power and a relay shut the power off. If I was to increase the alternator to output more power would it solve the problem?

 

[Big_John]

You need to look at the battery voltage with the lights on.

I'll bet the bulkhead connector etc. isn't up for the task of running the high draw lighting. Changing the alternator won't help.

A relay is a good idea because the switch isn't up for the task as the amperage draw is higher than stock. That won't prevent what is happening though.

So... start the car, check the voltage at the battery with and without the headlights on. Should be 13.5 or so. That's where you need to begin.

 

[Ironwolf]

Check the the bulkhead connection and or the main power wire going to the ammeter.

 

[1966newport]

the amps wont be higher with halogens

 

[ceebuddy]

the amps wont be higher with halogens

... on low beams. On high beams, it would be higher.

But what exactly is the symptom? Total loss of power and engine stalling? Or just the headlights quitting?

After a humid winter I had the problem of the engine quitting when I turned on too many electrical accessories. The battery terminal looked good, though. The culprit: oxidation build-up between the copper strands of the positive cable and the terminal connectors, which also showed some corrosion when I had removed the cable from the connector. A new connector cured the problem.

 

[Waggy]

With the halogen lights on, I could run the car for a short period of time, then it was like the battery died. No lights, radio or spark. The engine just stopped running. I had a new separate harness with it's own relay connected directly to the battery. I thought it was the fuse link from the battery, replaced it and car was OK, then drove the car home and got half way house and it happened again. Replaced the fuse again and then a block from home again and this time, the replacement fuse link did not work. Pushed it home, then tried the ignition again and it worked, so it is not the fuse, it just needed to cool down.

 

[ceebuddy]

Check the battery poles and clamps for oxidation as well as the connection between the pole clamps and the actual wire strands. It's easy to examine and it might be the culprit.