mmurphy77

My A/C is all factory correct and works beautifully. The only problem I seem to have is every couple of years I have to replace the inline fuse (coming off the horn relay to the high speed relay behind the booster). The last few times I've just soldered in a replacement parts store type (30A). It's seems to burn out during high demand on super hot, humid days. Also it doesn't just blow the fuse, it completely melts the housing and attaching points. The first time it happened I checked the circuit for an overload and found nothing unusual. This will be the 3rd time in 5 1/2 years. Once I replace it it works perfectly for a year or three. Can it be attributed to the $2.00 inline fuse I'm using or is there some other problem that could be the culprit? My blower motor doesn't seem like it's laboring at all or drawing on the system when I turn it on.

MDchanic

It could be because that fuse is supposed to be 30A.

- Eric

mmurphy77

It is a 30A fuse and holder. I typed 15A because my memory sucks .

jag1886

You want to find a good fuse holder that has a 10 or at a minimum 12 gauge wire coming out of it, they can be hard to find in this chinese world we live in. You might also want to check the blower motor, sounds like yours is drawing a lot of amps on high but if you are using the wrong fuse holder that may be your only problem.

matt69olds

Head to your favorite auto salvage yard, get a cooling fan plug off a later model GM car. Use a plug from a large fan, it should have 12 gauge wire. It will accept a ATO style fuse and wont melt.

mmurphy77

Thanks guys. Id rather not use an ATO style fuse out of the interest of originality. Even though my parts store replacement is not exactly original, once taped up it hides in plain sight a little better than a new style would. I'll have to 'get off my wallet' and try to find a better quality piece with heavier gauge wires.

Lady72nRob71

Good fuse holders are hard to find.
I took a heavy duty 30A Buss brand holder from Napa, removed the orange 12ga wires, and soldered on 10ga black wire from a similar vehicle, right to the holder's ends that contact the fuse (but not the fuse itself!) Looks great and should last a while...
I also added some heat shrink tubing to fill in the gap between the housing and the wire to keep water out.

Ozzie

It sounds like you may have an intermittent overload condition. Check to see if the blower motor's armature turns freely. If the bushings are starting to dry up, they may also be starting to bind. If that's O.K. look in the circuit for an intermittent short. It also could be that the motor's winding insulation may be breaking down.

BILL DEMMER

imo, the factory blower motor high speed wire is inadequate for the job, i would upgrade the entire high speed wiring to the next thicker gauge and leave it fused at 30 amps. the cylindrical glass fuses are not meant to be soldered to directly <<<could be your problem.


bill

mmurphy77

The fuse remains in the spring loaded housing, by soldering in a replacement I meant the lead-in wires to the fuse holder that I spliced in not the fuse itself. I'm going to replace it today with a higher quality holder and wire and we'll see if it'll last more than a couple of years.

mmurphy77

Replaced it this morning using a higher quality holder and it's working fine again. We'll see what happens in another 2 1/2 years.

MDchanic

Great!

I would recommend going around and feeling the wire and the fuse holder a few times during periods of prolonged High-speed fan use, to see if they feel warm - they shouldn't.

- Eric

mmurphy77

I will, thanks Eric.

Miles71

I agree with Ozzie suggestion on checking the blower, and a tip I got from Rob.
The next time you have the PS fender off, pull out the blower Motor (disconnect the power).
With the squirrel cadge still attached, spin the fan by hand as fast as you can,
and see how many times it rotates.

If it spins freely 1 or more turns, then your blower may still be good.
If it acts like my blower (42 years old), it would stop instantly when I removed my hand.
My blower was not popping fuses, however I decided to replace it anyway (MAW).

Lady72nRob71

I am beginning to think MAW is my middle name........

delta7388

With info from from this thread I've now got high speed again, - thanks guys as I didn't even know about the inline 30 amp fuse --cut out the original and replaced with ATC blade type--

Erik

'73 delta 88 royale 2 dr hdtp
'67 delta 88 2 dr hdtp

MDchanic

Great! It's good to know that others are helped by these threads, as well!

- Eric

m371961

And thanks for using search!