Community Forums

WEB552 · 04-20-2019, 05:59 PM

2004 Itasca Suncruiser. The heater fan motor blows s 30 A fuse when on high speed. It works fine on low or medium speed. any ideas?

Skip426 · 04-20-2019, 08:41 PM

Welcome to iRV2.

There could be an issue with the blower speed switch or the resister block that's causing the issue.
Was the 30 amp fuse original to the system ?
Or has someone installed that amp of fuse to try and deal with the problem.
Evans /Tempcon wiring diagrams have a 25 amp fuse shown.

**Petro** · 04-21-2019, 10:15 AM

My previous MH was a 2003 Chieftain. I had a similar problem. The problem was a bad bearing in the heater motor. Had to replace the heater motor and that solved the problem. It was not an easy fix either.

Don

Skiddy · 04-21-2019, 06:46 PM

Quote:

Originally Posted by Petro

My previous MH was a 2003 Chieftain. I had a similar problem. The problem was a bad bearing in the heater motor. Had to replace the heater motor and that solved the problem. It was not an easy fix either.

Don

that's what I am thinking, too much draw/load on the circuit

danhannah · 04-28-2019, 01:05 AM

It may be the resistor block. It is mounted in the blower box, which is grounded metal. The high power coils of the resistor block may have melted, touching the blower box.

The resistor block is easy to pull out and look at.

The reason I don't think it is the motor is that your fuse doesn't pop on low or medium speeds, which, combined with the resistor block, is about the same amp draw for all three speeds.

Less likely would be the blower switch itself being defective somehow, or the wiring for the high speed, but worth checking.

Let us know what you find. Best of luck.

WEB552 · 04-29-2019, 07:00 PM

So as usual I started replacing the most expensive parts first. I replaced the blower motor and resister pack. The problem was still there. I finally replaced the blower relay and that seems to have solved the problem, but I won't know for sure until I go on vacation in June. Other things that I discovered; Low speed and medium speed is supplied by a different fuse than the high speed on the blower. The low speeds are fused at 25 amps and the high speed is a separate 30 amp fuse that is energized all of the time. The Blower relay switches to the high speed fused circuit when the switch calls for it.
Thanks for the responses.