98 XJ Heater Fan Control Operates on "4" (High) Only

The heater fan control knob on the dash now only operates on "4"
(highest speed). I know it's simple enough to pull the dash bezel off
and replace the control, but before I order a new part, my question is
this: Before I go to the dealer or boneyard to find a new switch,
could anything else be causing the problem?

Thanks,

Mark
'98 XJ

If it only works on high then the resistor pack is probably toast. I am
betting the dash switch is fine. If the resistor pack is toast then you
should also change the blower motor out too. It probably caused the resistor
pack failure. Just changing out the resistor pack will probably be cheaper
but it will fry again.
KH


"M. E. Bye" > wrote in message
...
> The heater fan control knob on the dash now only operates on "4"
> (highest speed). I know it's simple enough to pull the dash bezel off
> and replace the control, but before I order a new part, my question is
> this: Before I go to the dealer or boneyard to find a new switch,
> could anything else be causing the problem?
>
> Thanks,
>
> Mark
> '98 XJ

What Kevin said. Take a look at the connections on the resistor pack if they
are cruded up give them a good clean and see if the fans speeds come back,
sometimes its just dirty. If not the resistor pack is gone.

Snow...

"Kevin in San Diego" > wrote in message
news:yTc0e.500$Mt5.252@fed1read01...
> If it only works on high then the resistor pack is probably toast. I am
> betting the dash switch is fine. If the resistor pack is toast then you
> should also change the blower motor out too. It probably caused the
> resistor pack failure. Just changing out the resistor pack will probably
> be cheaper but it will fry again.
> KH
>
>
> "M. E. Bye" > wrote in message
> ...
>> The heater fan control knob on the dash now only operates on "4"
>> (highest speed). I know it's simple enough to pull the dash bezel off
>> and replace the control, but before I order a new part, my question is
>> this: Before I go to the dealer or boneyard to find a new switch,
>> could anything else be causing the problem?
>>
>> Thanks,
>>
>> Mark
>> '98 XJ
>
>

It is a resistor as Kevin has already said. Below the whiskey
chest: http://www.billhughes.com/resistor.htm
God Bless America, ßill O|||||||O


"M. E. Bye" wrote:
>
> The heater fan control knob on the dash now only operates on "4"
> (highest speed). I know it's simple enough to pull the dash bezel off
> and replace the control, but before I order a new part, my question is
> this: Before I go to the dealer or boneyard to find a new switch,
> could anything else be causing the problem?
>
> Thanks,
>
> Mark
> '98 XJ

L.W.(ßill) Hughes III wrote:
> It is a resistor as Kevin has already said. Below the whiskey
> chest: http://www.billhughes.com/resistor.htm
> God Bless America, ßill O|||||||O
>
>
> "M. E. Bye" wrote:
>
>>The heater fan control knob on the dash now only operates on "4"
>>(highest speed). I know it's simple enough to pull the dash bezel off
>>and replace the control, but before I order a new part, my question is
>>this: Before I go to the dealer or boneyard to find a new switch,
>>could anything else be causing the problem?
>>
>>Thanks,
>>
>>Mark
>>'98 XJ

I don't have any experience of Jeep resistor packs, but others (like
Saab) have three large resistors (that rarely go) and a thermal fuse
(that often goes). The thermal fuse is an inexpensive item and a
replacement can be crimped on. Available from Tandy/Radio Shack.

The Saab had the problem since the resistor pack was located in the
airstream for cooling, but in position one there wasn't positive
airflow before the pack got too hot. After changing a thermal fuse in
one I found that by switching the fan to max and then to the desired
speed the thermal fuse didn't blow again.

I don't know how or if this applies to the Jeep.

--
Regards,
Danny

http://www.gaggia-espresso.com (a purely hobby site)
http://www.dannyscoffee.com (UK advert for my mobile espresso service)
http://www.malabargold.co.uk (UK/European online ordering for Malabar
Gold blend)
swap Z for above characters in email address to reply

blower resisitor failure is a common issue defaults to high speed

Danny wrote:

> L.W.(ßill) Hughes III wrote:
> > It is a resistor as Kevin has already said. Below the whiskey
> > chest: http://www.billhughes.com/resistor.htm
> > God Bless America, ßill O|||||||O
> >
> >
> > "M. E. Bye" wrote:
> >
> >>The heater fan control knob on the dash now only operates on "4"
> >>(highest speed). I know it's simple enough to pull the dash bezel off
> >>and replace the control, but before I order a new part, my question is
> >>this: Before I go to the dealer or boneyard to find a new switch,
> >>could anything else be causing the problem?
> >>
> >>Thanks,
> >>
> >>Mark
> >>'98 XJ
>
> I don't have any experience of Jeep resistor packs, but others (like
> Saab) have three large resistors (that rarely go) and a thermal fuse
> (that often goes). The thermal fuse is an inexpensive item and a
> replacement can be crimped on. Available from Tandy/Radio Shack.
>
> The Saab had the problem since the resistor pack was located in the
> airstream for cooling, but in position one there wasn't positive
> airflow before the pack got too hot. After changing a thermal fuse in
> one I found that by switching the fan to max and then to the desired
> speed the thermal fuse didn't blow again.
>
> I don't know how or if this applies to the Jeep.
>
> --
> Regards,
> Danny
>
> http://www.gaggia-espresso.com (a purely hobby site)
> http://www.dannyscoffee.com (UK advert for my mobile espresso service)
> http://www.malabargold.co.uk (UK/European online ordering for Malabar
> Gold blend)
> swap Z for above characters in email address to reply

mic canic wrote:
> blower resisitor failure is a common issue defaults to high speed
>

In the Saab design, since each speed has it's own resistor (apart from
full speed) it's unusual for the resistors to all go. There is
usually a thermal link that blows and can be replaced. Note: crimp,
not soldered.


--
Regards,
Danny

http://www.gaggia-espresso.com (a purely hobby site)
http://www.dannyscoffee.com (UK advert for my mobile espresso service)
http://www.malabargold.co.uk (UK/European online ordering for Malabar
Gold blend)
swap Z for above characters in email address to reply

The point is, that if the resistor blows then something is probably wrong
with your fan. Even if the Jeeps whole resistor pack magically
disintigrated, its a cheap easy part to replace. What caused the failure is
the issue here.
KH

On Thu, 24 Mar 2005 21:35:11 +0000, Danny wrote:
> mic canic wrote:
>> blower resisitor failure is a common issue defaults to high speed
>>
>
> In the Saab design, since each speed has it's own resistor (apart from
> full speed) it's unusual for the resistors to all go. There is
> usually a thermal link that blows and can be replaced. Note: crimp,
> not soldered.

FWIW my old Ford Escort ('91) was the same way.

On that one, though, I had the connector contacts corrode instead of
the fuse blow. The replacement I left hanging so it couldn't collect
water again, but during the summer my dad forgot and left the blower
on too long and blew the fuse (he was borrowing the car then). He
wrapped a bare piece of wire around the fuse to bypass it, but that
gives no protection against overheating and starting a fire.

-D

--
If you want to know what God thinks about money,
just look at the people He gives it to.
-- Old Irish Saying

www: http://dman13.dyndns.org/~dman/ jabber:

Kevin in San Diego wrote:
> The point is, that if the resistor blows then something is probably wrong
> with your fan. Even if the Jeeps whole resistor pack magically
> disintigrated, its a cheap easy part to replace. What caused the failure is
> the issue here.
> KH
>
>

Not necessarily. In the case of the Saab design, the resistors are
cooled by air movement through the blower assembly and in slower
settings there is insufficient airflow in the short space of time it
takes the thermal fuse to overheat. Starting the fan on full and then
turning it down to the desired setting allows positive airflow to be
established before the resistors are used.

--
Regards,
Danny

http://www.gaggia-espresso.com (a purely hobby site)
http://www.dannyscoffee.com (UK advert for my mobile espresso service)
http://www.malabargold.co.uk (UK/European online ordering for Malabar
Gold blend)
swap Z for above characters in email address to reply