1977 dodge motorette motorhome, hard starting.

[Grub54891]

As the title reads, this rig is starting hard in cold weather. 318 motor.
Little backstory: When we went to check out the rig, it was early spring, it cranked slow, but after messing around cleaning connections, and jump starting, it fired up ok. Bad starter. Replaced that the same day as purchased. Had no issues all summer, till now when the cold weather set in.
Went to start it last week so I could move it to its winter parking spot. Cranked fine, no spark-I actually put a spark checker on it. Wich brings us to today, I tried it again, still no spark. Power is at 12 volts at the coil, when cranking it drops to 11. Regardless, I got to thinking, when we were checking it out in the spring, it would not go at first either, so I left the ignition on for 15 minutes, went back and it fired right up. Now in my experience, a coil fails when its hot, not cold. Oh yeah, it's electronic, no points. Any thoughts of what could be the issue?

 

[alldodge]

I'm thinking connections with 11V while cranking. Leaving the key on heats up the coil a tad but also heats up the bad connection. If you can run a jumper from the bat to the coil (when cold) and it fires right up then look at connectors. Could be anything from the bat, to key to coil.

If its the same then look at grounds, including the module which is mounted on the firewall.

 

[Grub54891]

Yeah, I did run a jumper directly to the coil, no difference. I did clean up and change the battery ends, and grounds. There is a connecter going to the dizzy, cleaned that also. Dielectric grease on all. The only thing I didn't do yet is the module cleaning. That will be next. Thanks.

 

[Grub54891]

Cured! After doing most everything suggested, plus a couple more, I decided to do more troubleshooting. I went out with a heat gun, when the Temps were in the low 20's. Heated up the ignition module for a few minutes. Fired right up! Replaced the unit. Went out there again two days in a row, -10° both days. Fired up instantly. Thank's for the suggestions!