Chevy blower motor issues

[B.O.B.]

I did the swap and had to put a spacer between the motor and the heater box to keep the cage hitting the back side. Problem is I keep popping fuses. Have the motor grounded to the dash and it is getting power from the original wiring. Is there anything I should be looking at? I also blocked off the fresh air hose from the outside and ditched the box. Anybody ever try to put a pusher fan on the outside to push more air in?

[la hi]

GROUND, GROUND, GROUND, then a heavier wire from the power source to the heater motor!!

[Gunnibronco]

Mine was actually melting the solder inside the fuse, without blowing the fuse. It was an original harness & there was light rust on the contacts where the fuse snapped into the box. Cleaned up the contacts with some sandpaper and the problem was solved.

[la hi]

Good job!

[Kinder]

Willem’s was/is doing the same, plan is to replace the heater blower circuit with non 50 yo parts.

[Viperwolf1]

Mine was actually melting the solder inside the fuse, without blowing the fuse. It was an original harness & there was light rust on the contacts where the fuse snapped into the box. Cleaned up the contacts with some sandpaper and the problem was solved.

This is a common problem and is the result of the fuse contacts getting hot enough to melt solder. I replaced my fuse with a circuit breaker of the same rating and all is good.

You can find circuit breakers that fit in many '60s and '70s land yachts in the wrecking yards.

[B.O.B.]

Where is exactly would I put this breaker? Before the resistor, after, before the fuse?

[Viperwolf1]

Where is exactly would I put this breaker? Before the resistor, after, before the fuse?

In place of the fuse. They are available in many current ratings. You want the 20 amp version.

[B.O.B.]

Found the issue. My ECU came loose and was hitting the resistor causing it to short out. Luckily nothing was damaged. Working great now just need to change the thermostat.