When I got my van, the fuse for the blower motor had melted out of the fuse block, and the previous owner had installed an inline fuse.

After a few years this inline fuse holder melted. I replaced it with a new one.

That one too lasted a few years.
I replaced it with an ATC fuse holder and got a few more years.
Yesterday that one melted.

I replaced it with a Maxi fuse, cause I had one on hand.

The circuit is supposed to be fused at 30 amps. I only have 20 amp or 100 amp maxi fuses so I fused it at 20 amps.

I have a clamp on Ammeter

Battery voltage was at 12.4 at time of test, engine not running.
Low speed was drawing 4.5 amps and voltage measured at fuse was 12.08
Medium 6.73a and 11.90v
High 10.04amps and 11.59volts
Max 14.22amps and 11.26 volts.

The blower motor was replaced by previous owner pre 2001
I've had no resistor issues.
The selector switch had issues but a cleaning and spring retensioning has been fine for several years now.

Anybody own a clamp on Ammeter and want to stick a jumper wire in their fuse receptacle and see how much current their fan is pulling?

I don't really think the motor is the issue. Every time it has been the fuse holder itself which melts. Not the butt connectors, no other wiring, just the fuse holder, and this latest time, the ATC fuse itself along with the holder.

I drove around a bunch today, and the Maxi fuse did not even seem warm with the fan on high speed.





New maxifuse with 8 awg leads:


The van is an '89

Looks like they switched to a different blower motor after '97, though it appears the same in pics.

 

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The fuse holder in the photo, I do not remember which brand, but I know I bought in an AP store and it had 12 awg leads. One would think with 12 awg leads it would be fairly robust.


The previous fuse holders were the inline glass type fuse holders, again, do not know brand.

This latest failure happened while driving with blower motor on Max, heater blaring. I started smelling something about a mile from home that did not smell like the normal burning wiring smell, thought it was the car in front of me or some construction en route.

As I was backing into my driveway, it got bad and I noticed smoke.

I shut off the engine and turned on my light and saw smoke pouring outta my glove box. Turned off my battery switch. Disconnecting all stock circuit paths.

So it was not a instantaneous fuse melting, but a few minutes of passing current powering the blower motor on max which melted it. The motor does not seem to be struggling, throwing just as much air as always.

I've had no issues, so far, with the new Maxifuse holder installed, and the 20 amp maxifuse fuse has not tripped in what is to be fused at 30 amps.

I need to check how much current the motor is pulling at battery charging voltages/ engine running, and after it has been running for a while.

DC clampmeters are great tools to have, especially since their prices have come down

Not professional quality, but I got a craftsman Model # 82369, and it has been much used since acquisition. right around 50$

'97 was the last year that lists the same blower motor as mine.

Almost tempted to order a new one, just to test/ compare the current and sending it back if my current one is inline

 

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