Heater fan fuse melted, fan doesn't work at all

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VectraGoVroom
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Heater fan fuse melted, fan doesn't work at all

Post by VectraGoVroom »

Welp, I had a good few months of driving without any worries! Now it seems my heater fan is acting up. I hadn't even notice the fan shutting off for a long while. The number 4 fuse was melted with a bunch of yellow crap on the connectors. The fuse was still good, but the connectors got coated and wouldn't make contact. I pulled the wires out of the fuse block to clean them up and test them with a multimeter. The connection is fine, 12V going from one side to the other, yet the fan does nothing.
I've had an intermittent chirping noise from the fan ever since I got the car, it usually went away by changing fan speeds. Possibly related? Any ideas?
Call them Cavs, but mine's a Veccy. <3
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Mk3alan
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Re: Heater fan fuse melted, fan doesn't work at all

Post by Mk3alan »

Have you got the supply and earth at the fan? My old Astra heater motor used the make a hell of a racket - cured once motors bearings were oiled, they do dry out.

Alan
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Robsey
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Re: Heater fan fuse melted, fan doesn't work at all

Post by Robsey »

Yep -
Sounds like the motor bearings have dried up causing excess current draw.

It may be an idea to check all the fan wiring from the fuse, switch and the motor itself under the scuttle panel at the back of the engine bay.

Be a good idea to check the resistor pack too.
When the fan gets dry or uses too much current, it is very common for the thermal fuse on the side of the resistor pack to fail.

So your mission should you choose to take it is -

1 - Take out the blower motor and check that it spins freely.
If it is stiff, drip some 3 in 1 oil or similar on the armature bearings.

2 - Check the thermal fuse on the resistor pack. You can get replacement fuses for about €1 each from your local electronic specialist shop.
In the UK we have Maplin Electronics, RS Components and Farnell In One Online.

3 - Check wiring to switch, fuse and motor body.

If all that fails, you may need to get a replacement motor from a scrap yard.

Last time I looked, a blower motor from the dealer was about €150... eek!!
Although they may not be available any more.
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Cavalier342
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Re: Heater fan fuse melted, fan doesn't work at all

Post by Cavalier342 »

I've had this happen on my old early model, I ended up fitting an in-line fuse behind the fusebox in place of the standard melted number 4 slot. The fans themselves are prone to being troublesome after a number of years, general dust, dirt, moisture, and lack of lubricant all add up to it. As above, you can probably just give it some oil on the bearings, clean up the contacts, and I would advise putting in a separate in-line fuse to stop any more melting on the fusebox itself. Ideally the same Amp rating.
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Kings Blue 1992 Vauxhall Cavalier LSi Auto C18NZ
Smoke Grey 1994 Vauxhall Cavalier V6 C25XE

Am I a light sleeper or a heavy sleeper? Well that depends on how much I've had to drink...
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VectraGoVroom
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Re: Heater fan fuse melted, fan doesn't work at all

Post by VectraGoVroom »

Cheers! Ended up being a blown thermal fuse. I took the whole motor out, gave it some PTFE lube on both bearings, replaced the fuse for one euro, stuck it back together aand spliced in an inline fuse holder to replace the burnt 30A socket. Works perfectly and sounds a whoole lot smoother now. Used to be the first thing I'd hear was squeaking on turning the fan on, now it's smooth as butter.
Call them Cavs, but mine's a Veccy. <3
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Cavalier342
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Re: Heater fan fuse melted, fan doesn't work at all

Post by Cavalier342 »

Excellent, nice easy fix. Should last for ages now.
Previous:
China Blue 1989 Vauxhall Cavalier L 18SV
Kings Blue 1992 Vauxhall Cavalier LSi Auto C18NZ
Smoke Grey 1994 Vauxhall Cavalier V6 C25XE

Am I a light sleeper or a heavy sleeper? Well that depends on how much I've had to drink...
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Robsey
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Re: Heater fan fuse melted, fan doesn't work at all

Post by Robsey »

Excellent a good cheap fix.

My favourite type of fix :)
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James McGrath
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Re: Heater fan fuse melted, fan doesn't work at all

Post by James McGrath »

Jolly good. :thumb

Quite a common problem for that thermal fuse to blow out. I had to replace it on my Diplomat a coupe of years ago.
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Cavalier342
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Re: Heater fan fuse melted, fan doesn't work at all

Post by Cavalier342 »

It's only a common problem because it's not a part that ever gets replaced or looked at, so after 20 years of use it just fails, same as most small components. Once it's fixed, it's no longer a problem.
Previous:
China Blue 1989 Vauxhall Cavalier L 18SV
Kings Blue 1992 Vauxhall Cavalier LSi Auto C18NZ
Smoke Grey 1994 Vauxhall Cavalier V6 C25XE

Am I a light sleeper or a heavy sleeper? Well that depends on how much I've had to drink...
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