A/C problem solutions?

Hi all,
I've got a 1994 4runner that blows the 10 amp A/C fuse whenever I try
to run the A/C. I've checked all the outputs from the amplifier board
and none are shorted (except of course the ground connection) so I'm
guessing the magnetic clutch and relays are ok. Does this then mean
the board is shorting to ground internally and needs to be replaced?

I hope someone has seen this before as no one around here has.

Thanks for any help you can give me.

dennis
in nca

On 15 Jun 2006 10:06:11 -0700, "rigger" <dgrup@aol.com> wrote:
[color=blue]
>Hi all,
>I've got a 1994 4runner that blows the 10 amp A/C fuse whenever I try
>to run the A/C. I've checked all the outputs from the amplifier board
>and none are shorted (except of course the ground connection) so I'm
>guessing the magnetic clutch and relays are ok. Does this then mean
>the board is shorting to ground internally and needs to be replaced?
>
>I hope someone has seen this before as no one around here has.
>
>Thanks for any help you can give me.
>
>dennis
>in nca[/color]


Check for shorts in underhood wiring to compressor and for a shorted
compressor clutch coil too.
-----------------
The SnoMan
[url]www.thesnoman.com[/url]

"rigger" <dgrup@aol.com> wrote:
[color=blue]
>Hi all,
>I've got a 1994 4runner that blows the 10 amp A/C fuse whenever I try
>to run the A/C. I've checked all the outputs from the amplifier board
>and none are shorted (except of course the ground connection) so I'm
>guessing the magnetic clutch and relays are ok. Does this then mean
>the board is shorting to ground internally and needs to be replaced?
>[/color]
Are you sure it's supposed to be a 10 amp?

All mine are 30 amp, newer vehicles but still 10 amp is very low.

SnoMan wrote:
[color=blue]
> On 15 Jun 2006 10:06:11 -0700, "rigger" <dgrup@aol.com> wrote:
> Check for shorts in underhood wiring to compressor and for a shorted
> compressor clutch coil too.
> -----------------
> The SnoMan
> [url]www.thesnoman.com[/url][/color]

Thanks for responding:

No shorts I can find. Would you or anyone else know the correct
resistance for the clutch? It's not at a dead short at this time but
perhaps it's only partially shorted? :(

dennis
in nca

Dave wrote:[color=blue]
> "rigger" <dgrup@aol.com> wrote:[color=green]
> >[/color]
> Are you sure it's supposed to be a 10 amp?
>
> All mine are 30 amp, newer vehicles but still 10 amp is very low.[/color]

On this 4runner the 10 amp feeds the A/C amplifier which feeds a couple
of relays and a thermister in addition to the A/C clutch. There's also
a 20 amp which feeds the blower motor, etc.

dennis
in nca

rigger wrote:[color=blue]
> Hi all,
> I've got a 1994 4runner that blows the 10 amp A/C fuse whenever I try
> to run the A/C. I've checked all the outputs from the amplifier board
> and none are shorted (except of course the ground connection) so I'm
> guessing the magnetic clutch and relays are ok. Does this then mean
> the board is shorting to ground internally and needs to be replaced?
>
> I hope someone has seen this before as no one around here has.
>
> Thanks for any help you can give me.
>
> dennis
> in nca[/color]

Would anyone know of other groups or sites that might have some info?
Thanks all.

dennis
in nca

Have you tried to unplug the magnetic clutch and measure voltage at the
plug. If you get proper voltage and the fuse doesn't blow, it points to the
magnetic clutch. If it does blow the fuse, keep searching but you know it's
not the magnetic clutch.

Paul.

"rigger" <dgrup@aol.com> wrote in message
news:1150391171.359542.259590@i40g2000cwc.googlegroups.com...[color=blue]
> Hi all,
> I've got a 1994 4runner that blows the 10 amp A/C fuse whenever I try
> to run the A/C. I've checked all the outputs from the amplifier board
> and none are shorted (except of course the ground connection) so I'm
> guessing the magnetic clutch and relays are ok. Does this then mean
> the board is shorting to ground internally and needs to be replaced?
>
> I hope someone has seen this before as no one around here has.
>
> Thanks for any help you can give me.
>
> dennis
> in nca
>[/color]

Paul. wrote:[color=blue]
> Have you tried to unplug the magnetic clutch and measure voltage at the
> plug. If you get proper voltage and the fuse doesn't blow, it points to the
> magnetic clutch. If it does blow the fuse, keep searching but you know it's
> not the magnetic clutch.
>
> Paul.
>
> "rigger" <dgrup@aol.com> wrote in message
> news:1150391171.359542.259590@i40g2000cwc.googlegroups.com...[color=green]
> > Hi all,
> > I've got a 1994 4runner that blows the 10 amp A/C fuse whenever I try
> > to run the A/C. I've checked all the outputs from the amplifier board
> > and none are shorted (except of course the ground connection) so I'm
> > guessing the magnetic clutch and relays are ok. Does this then mean
> > the board is shorting to ground internally and needs to be replaced?
> >
> > I hope someone has seen this before as no one around here has.
> >
> > Thanks for any help you can give me.
> >
> > dennis
> > in nca
> >[/color][/color]

Thanks Paul. That sounds like a good idea; I'll try it in the morning.

dennis

rigger wrote:[color=blue]
> Paul. wrote:[color=green]
> > Have you tried to unplug the magnetic clutch and measure voltage at the
> > plug. If you get proper voltage and the fuse doesn't blow, it points to the
> > magnetic clutch. If it does blow the fuse, keep searching but you know it's
> > not the magnetic clutch.
> >
> > Paul.[/color]
>
> Thanks Paul. That sounds like a good idea; I'll try it in the morning.
>
> dennis[/color]

Well I isolated it to the clutch (or wiring to same).

Couldn't get at the wire loom connection (it's buried on top of the
compressor); I can't reach it without pulling the compressor. What I
did was to hammer out flat the ends of some finishing nails and put
these ends into the amplifier connector and used jumpers (from Radio
Shack) to connect to the board. I didn't connect the power wire to the
compressor clutch (black with yellow stripe) and when I fired it up the
fuse did not blow. On the other hand, with this hooked up with the
clutch wire in the circuit "POW", one more fuse bites the dust.

Looks like another job is on the list.

Thanks to everyone for reading and for those who could help.

dennis
in nca

From a post on A/C problems, some good reading on the controls associated
with the A/C.
Paul.

Info tip I found:
<http://www.findarticles.com/p/articles/mi_qa3828/is_200206/ai_n9092114>

just right click -highlight & copy and paste in your address bar to open.

"rigger" <dgrup@aol.com> wrote in message
news:1150391171.359542.259590@i40g2000cwc.googlegroups.com...[color=blue]
> Hi all,
> I've got a 1994 4runner that blows the 10 amp A/C fuse whenever I try
> to run the A/C. I've checked all the outputs from the amplifier board
> and none are shorted (except of course the ground connection) so I'm
> guessing the magnetic clutch and relays are ok. Does this then mean
> the board is shorting to ground internally and needs to be replaced?
>
> I hope someone has seen this before as no one around here has.
>
> Thanks for any help you can give me.
>
> dennis
> in nca
>[/color]

"rigger" <dgrup@aol.com> wrote in message news:1150391171.359542.259590@i40g2000cwc.googlegroups.com...[color=blue]
> Hi all,
> I've got a 1994 4runner that blows the 10 amp A/C fuse whenever I try
> to run the A/C. I've checked all the outputs from the amplifier board
> and none are shorted (except of course the ground connection) so I'm
> guessing the magnetic clutch and relays are ok. Does this then mean
> the board is shorting to ground internally and needs to be replaced?
>
> I hope someone has seen this before as no one around here has.
>
> Thanks for any help you can give me.
>
> dennis
> in nca
>
>[/color]


Check the resistance of the stator coil (magnetic clutch) with a ohm meter.

Mine was damaged from battery acid (I guess) and blowing the fuse just like that
with 2.6 ohms resistance. It worked fine when testing with a 12 volt (15 amp fuse) power source
and fooled me for quite awhile. :/

1987 Supra stator coils resistance shows 2.7 - 3.1 ohms at 68f degree

GL
Dan

On Thu, 03 Aug 2006 23:14:33 GMT, "Danny G." <dandog@pacbell.net>
wrote:
[color=blue]
>Check the resistance of the stator coil (magnetic clutch) with a ohm meter.
>
>Mine was damaged from battery acid (I guess) and blowing the fuse just like that
>with 2.6 ohms resistance. It worked fine when testing with a 12 volt (15 amp fuse) power source
>and fooled me for quite awhile. :/[/color]


Just remember that a magnetic coild has static resistance and a actaul
impedance when powered and clutch pulled in. (it will vary)
-----------------
The SnoMan
[url]www.thesnoman.com[/url]

"SnoMan" <admin@snoman.com> wrote in message news:bj45d21ip95fu1hs4rnis7c0qpf1dinu54@4ax.com...[color=blue]
> On Thu, 03 Aug 2006 23:14:33 GMT, "Danny G." <dandog@pacbell.net>
> wrote:
>[color=green]
>>Check the resistance of the stator coil (magnetic clutch) with a ohm meter.
>>
>>Mine was damaged from battery acid (I guess) and blowing the fuse just like that
>>with 2.6 ohms resistance. It worked fine when testing with a 12 volt (15 amp fuse) power source
>>and fooled me for quite awhile. :/[/color]
>
>
> Just remember that a magnetic coild has static resistance and a actaul
> impedance when powered and clutch pulled in. (it will vary)
> -----------------
> The SnoMan
> [url]www.thesnoman.com[/url][/color]

Woops, forgot to type the specified range was 2.7 - 3.2 ohms at 68f degree.
8)

On Fri, 04 Aug 2006 20:05:04 GMT, "Danny G." <dandog@pacbell.net>
wrote:
[color=blue]
>
>"SnoMan" <admin@snoman.com> wrote in message news:bj45d21ip95fu1hs4rnis7c0qpf1dinu54@4ax.com...[color=green]
>> On Thu, 03 Aug 2006 23:14:33 GMT, "Danny G." <dandog@pacbell.net>
>> wrote:
>>[color=darkred]
>>>Check the resistance of the stator coil (magnetic clutch) with a ohm meter.
>>>
>>>Mine was damaged from battery acid (I guess) and blowing the fuse just like that
>>>with 2.6 ohms resistance. It worked fine when testing with a 12 volt (15 amp fuse) power source
>>>and fooled me for quite awhile. :/[/color]
>>
>>
>> Just remember that a magnetic coild has static resistance and a actaul
>> impedance when powered and clutch pulled in. (it will vary)
>> -----------------
>> The SnoMan
>> [url]www.thesnoman.com[/url][/color]
>
>Woops, forgot to type the specified range was 2.7 - 3.2 ohms at 68f degree.
>8)
>[/color]

What you are really looking for here is a short or a open (a short in
this case because a 2.5 ohm reading or a bit less does not always mean
it is bad.
-----------------
The SnoMan
[url]www.thesnoman.com[/url]