Hello all,I posted a while back and can't seem to find my posted question. I'm wondering how I stop the dimming of lights at low idle? I believe there was a wiring harness to buy that helps this.Also is there a bigger alt.(with part no.) that I can put on the 440 block?When I bought the stroker it came with a single wire alt. but I don't know how to rewire the existing to use it.

You can check the Moparts Tech Archive. Lots of information on the subject, plus you can Google search about the topic as well.

Oftentimes, the Headlight Switch in our old cars is an antique and rather corroded, a weak link. Replacement switches are available and relatively cheap.

Beyond that, rewiring using relays so as to not send the heavy headlight current through the headlight switch and firewall connection, is a way to get rid of the dimming-at-idle and overall brightness issues.

Upgrading the wiring to the alternator ( along with circuit protection, fuses, fuseable-link, etc) can help the entire system as well.

if you have a less than std dia crank pulley (7.25") going to a 7.25 will speed up the alt (& pump which is generally OK) & may or may not require a smaller pump pulley depending on the current ones' dia so a std (7.25) crank pulley will fit which will speed up the pump even more. I'd clean ALL connections/wiring. The easiest would be to relay the headlight directly to the alt which works very well (keeps the ammeter honest also) & there's no downsides to this (maintain good relays/wiring/terminals/connections). As said there are other alt options that charge better at idle.

On my Cuda, I eliminated the dimming and reduced firewall harness load by adding a bypass wire between the Alternator and Starter Relay stud and I added hidden relays under the battery to power all of the lights.

As it was pointed out, the power has to run through a crap-ton of connections before it ever gets to the lights so there is plenty of opportunity for voltage reduction.

Power leaves the Alternator then crosses through a bulkhead connection to get to weld at the ammeter. From there it goes to the light switch then into the foot dimmer then through another bulkhead harness to get to the lights. I think I left out a connection but you get the idea. Increasing the (idle) output of your Alternator with a different ALT one or smaller pulley will give you more power at low-RPMs but if your wiring system already has high resistance from older connections you will put further strain on those connections.

Relays near the lights will help you get their feed closer to the battery which helps but in my opinion it is not enough. Even if you connect the lights directly to the battery, the power still has come from the Alt which means you are sending the power through four firewall connectors and across the weld near the ammeter.

Installing relays and adding an Alternator bypass wire makes sure the load stays on the engine side of the firewall and takes considerable strain off the old connections in our cars.

Your alt. should be putting out 14.2 volts at idle. If you have one diode out it will cause this problem.. What is you idle rpm? should be 750..

i have a single wire powermaster in my garage that came with the stroker motor.....not sure what i have to do to run the single wire and i think it wouldn't bolt in or something????


also thanks for all the help guys

All good suggestions above. I'll just add that the lights dim at low idle by original design. Even in tip top shape the original charging system on 60's/early/mid 70's MOPAR's has the dim at idle syndrome. The OE alternators just do not have a lot of idle output. Many cars lived long lives that way.

Best of the bunch is the latest squareback from the mid 70's. 78 amps rated output and ~50 at idle. It is available reman but reman quality seems variable with 30+ YO cores... the new Powermaster version is a better bet I think.

If you have the 75-80 amp one wire version of the squareback it may help the dim problem and bolt up OK. Suggestions for 1 wire hook-up. 1) Run a heavy wire from alternator output to fender relay. Minimum 8 gauge with either 12 gauge fusible link or 100 amp fuse. 2) tape or remove VR wires. 3) Install a volt meter on a switched 12V source as the ammeter will no longer be functional. 4) Connecting the original charge wire to the alternator is optional... it can help feed the bulkhead connector and supplement the feed from the fender relay but not critical.