4WD part-time light question

Just wondering what turns on and off the 4wd part-time and full-time lights
on a 93 XJ (4.0, atw4 tranny)? I noticed last night that the indicator
lights don't turn on. T-case still shifts and engages into both 4wd drive
settings, this morning a few local roads were just slippery enough to allow
me to shift into 4 high and try it. Does the light get turned on by the
same vac. switch as the t-case?

Snow...93 XJ

The older YJ's and XJ's had a vacumn switch sitting up on the firewall,
right next to the battery. Switch cuts in only after the front axle is
locked. Newer models have the switch as an intergal part of the diaphram
on the front axle. Cutover was '91 on the YJ, a year or so earlier on
the XJ. You can easily check which you have: old units have 3 vac ports
on the axle, newer ones have 2 vac ports and a wire terminal.

Did you actually get inot 4wd? Keep in mind that your transfer case can
switch into 4WD, your axle may not have made it. The light does not come
on until it is locked. Usual problem is bad vac harnes, next is the vac
switch on the tranny. Or just the usual assortment of bad wire, bunred
out bulb. Harness runs about $35 at the dealer, switch is about $16.
Lots of guys go with the manual cable, $200 as an accessory, less if you
make your own.

Snow wrote:
> Just wondering what turns on and off the 4wd part-time and full-time lights
> on a 93 XJ (4.0, atw4 tranny)? I noticed last night that the indicator
> lights don't turn on. T-case still shifts and engages into both 4wd drive
> settings, this morning a few local roads were just slippery enough to allow
> me to shift into 4 high and try it. Does the light get turned on by the
> same vac. switch as the t-case?
>
> Snow...93 XJ
>
>

The older YJ's and XJ's had a vacumn switch sitting up on the firewall,
right next to the battery. Switch cuts in only after the front axle is
locked. Newer models have the switch as an intergal part of the diaphram
on the front axle. Cutover was '91 on the YJ, a year or so earlier on
the XJ. You can easily check which you have: old units have 3 vac ports
on the axle, newer ones have 2 vac ports and a wire terminal.

Did you actually get inot 4wd? Keep in mind that your transfer case can
switch into 4WD, your axle may not have made it. The light does not come
on until it is locked. Usual problem is bad vac harnes, next is the vac
switch on the tranny. Or just the usual assortment of bad wire, bunred
out bulb. Harness runs about $35 at the dealer, switch is about $16.
Lots of guys go with the manual cable, $200 as an accessory, less if you
make your own.

Snow wrote:
> Just wondering what turns on and off the 4wd part-time and full-time lights
> on a 93 XJ (4.0, atw4 tranny)? I noticed last night that the indicator
> lights don't turn on. T-case still shifts and engages into both 4wd drive
> settings, this morning a few local roads were just slippery enough to allow
> me to shift into 4 high and try it. Does the light get turned on by the
> same vac. switch as the t-case?
>
> Snow...93 XJ
>
>

Yeah I'm pretty sure it went fully into 4 high, I turned 4 corners 2 of
them slippery the other 2 were dry. I wasn't going fast and the 2 corners
that were dry I could feel the front wheels do the "hop" they do when in 4wd
on a dry surface. I used to park in an semi underground parking lot, or
rather had to drive through one to get to my parking spot and needed 4wd
before I entered and after I exited to get into my spot (had turn a couple
corners and the front would hop if it was in 4wd). I haven't checked the
bulb yet, I'll do that tomorrow when I get home from work.

Snow...

"RoyJ" > wrote in message
k.net...
> The older YJ's and XJ's had a vacumn switch sitting up on the firewall,
> right next to the battery. Switch cuts in only after the front axle is
> locked. Newer models have the switch as an intergal part of the diaphram
> on the front axle. Cutover was '91 on the YJ, a year or so earlier on
> the XJ. You can easily check which you have: old units have 3 vac ports
> on the axle, newer ones have 2 vac ports and a wire terminal.
>
> Did you actually get inot 4wd? Keep in mind that your transfer case can
> switch into 4WD, your axle may not have made it. The light does not come
> on until it is locked. Usual problem is bad vac harnes, next is the vac
> switch on the tranny. Or just the usual assortment of bad wire, bunred
> out bulb. Harness runs about $35 at the dealer, switch is about $16.
> Lots of guys go with the manual cable, $200 as an accessory, less if you
> make your own.
>
> Snow wrote:
> > Just wondering what turns on and off the 4wd part-time and full-time
lights
> > on a 93 XJ (4.0, atw4 tranny)? I noticed last night that the indicator
> > lights don't turn on. T-case still shifts and engages into both 4wd
drive
> > settings, this morning a few local roads were just slippery enough to
allow
> > me to shift into 4 high and try it. Does the light get turned on by
the
> > same vac. switch as the t-case?
> >
> > Snow...93 XJ
> >
> >

Yeah I'm pretty sure it went fully into 4 high, I turned 4 corners 2 of
them slippery the other 2 were dry. I wasn't going fast and the 2 corners
that were dry I could feel the front wheels do the "hop" they do when in 4wd
on a dry surface. I used to park in an semi underground parking lot, or
rather had to drive through one to get to my parking spot and needed 4wd
before I entered and after I exited to get into my spot (had turn a couple
corners and the front would hop if it was in 4wd). I haven't checked the
bulb yet, I'll do that tomorrow when I get home from work.

Snow...

"RoyJ" > wrote in message
k.net...
> The older YJ's and XJ's had a vacumn switch sitting up on the firewall,
> right next to the battery. Switch cuts in only after the front axle is
> locked. Newer models have the switch as an intergal part of the diaphram
> on the front axle. Cutover was '91 on the YJ, a year or so earlier on
> the XJ. You can easily check which you have: old units have 3 vac ports
> on the axle, newer ones have 2 vac ports and a wire terminal.
>
> Did you actually get inot 4wd? Keep in mind that your transfer case can
> switch into 4WD, your axle may not have made it. The light does not come
> on until it is locked. Usual problem is bad vac harnes, next is the vac
> switch on the tranny. Or just the usual assortment of bad wire, bunred
> out bulb. Harness runs about $35 at the dealer, switch is about $16.
> Lots of guys go with the manual cable, $200 as an accessory, less if you
> make your own.
>
> Snow wrote:
> > Just wondering what turns on and off the 4wd part-time and full-time
lights
> > on a 93 XJ (4.0, atw4 tranny)? I noticed last night that the indicator
> > lights don't turn on. T-case still shifts and engages into both 4wd
drive
> > settings, this morning a few local roads were just slippery enough to
allow
> > me to shift into 4 high and try it. Does the light get turned on by
the
> > same vac. switch as the t-case?
> >
> > Snow...93 XJ
> >
> >

Check the connection on the axle before pulling the dash off to get at
the bulbs. Put it in 4wd, move forward and backward a few feet to help
drop it in, see if the swich reads close to zero ohms. then see if the
connector is any good.

Snow wrote:
> Yeah I'm pretty sure it went fully into 4 high, I turned 4 corners 2 of
> them slippery the other 2 were dry. I wasn't going fast and the 2 corners
> that were dry I could feel the front wheels do the "hop" they do when in 4wd
> on a dry surface. I used to park in an semi underground parking lot, or
> rather had to drive through one to get to my parking spot and needed 4wd
> before I entered and after I exited to get into my spot (had turn a couple
> corners and the front would hop if it was in 4wd). I haven't checked the
> bulb yet, I'll do that tomorrow when I get home from work.
>
> Snow...
>
> "RoyJ" > wrote in message
> k.net...
>
>>The older YJ's and XJ's had a vacumn switch sitting up on the firewall,
>>right next to the battery. Switch cuts in only after the front axle is
>>locked. Newer models have the switch as an intergal part of the diaphram
>>on the front axle. Cutover was '91 on the YJ, a year or so earlier on
>>the XJ. You can easily check which you have: old units have 3 vac ports
>>on the axle, newer ones have 2 vac ports and a wire terminal.
>>
>>Did you actually get inot 4wd? Keep in mind that your transfer case can
>>switch into 4WD, your axle may not have made it. The light does not come
>>on until it is locked. Usual problem is bad vac harnes, next is the vac
>>switch on the tranny. Or just the usual assortment of bad wire, bunred
>>out bulb. Harness runs about $35 at the dealer, switch is about $16.
>>Lots of guys go with the manual cable, $200 as an accessory, less if you
>>make your own.
>>
>>Snow wrote:
>>
>>>Just wondering what turns on and off the 4wd part-time and full-time
>
> lights
>
>>>on a 93 XJ (4.0, atw4 tranny)? I noticed last night that the indicator
>>>lights don't turn on. T-case still shifts and engages into both 4wd
>
> drive
>
>>>settings, this morning a few local roads were just slippery enough to
>
> allow
>
>>>me to shift into 4 high and try it. Does the light get turned on by
>
> the
>
>>>same vac. switch as the t-case?
>>>
>>>Snow...93 XJ
>>>
>>>
>
>
>

Check the connection on the axle before pulling the dash off to get at
the bulbs. Put it in 4wd, move forward and backward a few feet to help
drop it in, see if the swich reads close to zero ohms. then see if the
connector is any good.

Snow wrote:
> Yeah I'm pretty sure it went fully into 4 high, I turned 4 corners 2 of
> them slippery the other 2 were dry. I wasn't going fast and the 2 corners
> that were dry I could feel the front wheels do the "hop" they do when in 4wd
> on a dry surface. I used to park in an semi underground parking lot, or
> rather had to drive through one to get to my parking spot and needed 4wd
> before I entered and after I exited to get into my spot (had turn a couple
> corners and the front would hop if it was in 4wd). I haven't checked the
> bulb yet, I'll do that tomorrow when I get home from work.
>
> Snow...
>
> "RoyJ" > wrote in message
> k.net...
>
>>The older YJ's and XJ's had a vacumn switch sitting up on the firewall,
>>right next to the battery. Switch cuts in only after the front axle is
>>locked. Newer models have the switch as an intergal part of the diaphram
>>on the front axle. Cutover was '91 on the YJ, a year or so earlier on
>>the XJ. You can easily check which you have: old units have 3 vac ports
>>on the axle, newer ones have 2 vac ports and a wire terminal.
>>
>>Did you actually get inot 4wd? Keep in mind that your transfer case can
>>switch into 4WD, your axle may not have made it. The light does not come
>>on until it is locked. Usual problem is bad vac harnes, next is the vac
>>switch on the tranny. Or just the usual assortment of bad wire, bunred
>>out bulb. Harness runs about $35 at the dealer, switch is about $16.
>>Lots of guys go with the manual cable, $200 as an accessory, less if you
>>make your own.
>>
>>Snow wrote:
>>
>>>Just wondering what turns on and off the 4wd part-time and full-time
>
> lights
>
>>>on a 93 XJ (4.0, atw4 tranny)? I noticed last night that the indicator
>>>lights don't turn on. T-case still shifts and engages into both 4wd
>
> drive
>
>>>settings, this morning a few local roads were just slippery enough to
>
> allow
>
>>>me to shift into 4 high and try it. Does the light get turned on by
>
> the
>
>>>same vac. switch as the t-case?
>>>
>>>Snow...93 XJ
>>>
>>>
>
>
>

Where would I find the switch, I haven't looked yet, or is it quite easy to
see?

Snow...

"RoyJ" > wrote in message
news
> Check the connection on the axle before pulling the dash off to get at
> the bulbs. Put it in 4wd, move forward and backward a few feet to help
> drop it in, see if the swich reads close to zero ohms. then see if the
> connector is any good.
>
> Snow wrote:
> > Yeah I'm pretty sure it went fully into 4 high, I turned 4 corners 2 of
> > them slippery the other 2 were dry. I wasn't going fast and the 2
corners
> > that were dry I could feel the front wheels do the "hop" they do when in
4wd
> > on a dry surface. I used to park in an semi underground parking lot, or
> > rather had to drive through one to get to my parking spot and needed 4wd
> > before I entered and after I exited to get into my spot (had turn a
couple
> > corners and the front would hop if it was in 4wd). I haven't checked
the
> > bulb yet, I'll do that tomorrow when I get home from work.
> >
> > Snow...
> >
> > "RoyJ" > wrote in message
> > k.net...
> >
> >>The older YJ's and XJ's had a vacumn switch sitting up on the firewall,
> >>right next to the battery. Switch cuts in only after the front axle is
> >>locked. Newer models have the switch as an intergal part of the diaphram
> >>on the front axle. Cutover was '91 on the YJ, a year or so earlier on
> >>the XJ. You can easily check which you have: old units have 3 vac ports
> >>on the axle, newer ones have 2 vac ports and a wire terminal.
> >>
> >>Did you actually get inot 4wd? Keep in mind that your transfer case can
> >>switch into 4WD, your axle may not have made it. The light does not come
> >>on until it is locked. Usual problem is bad vac harnes, next is the vac
> >>switch on the tranny. Or just the usual assortment of bad wire, bunred
> >>out bulb. Harness runs about $35 at the dealer, switch is about $16.
> >>Lots of guys go with the manual cable, $200 as an accessory, less if you
> >>make your own.
> >>
> >>Snow wrote:
> >>
> >>>Just wondering what turns on and off the 4wd part-time and full-time
> >
> > lights
> >
> >>>on a 93 XJ (4.0, atw4 tranny)? I noticed last night that the
indicator
> >>>lights don't turn on. T-case still shifts and engages into both 4wd
> >
> > drive
> >
> >>>settings, this morning a few local roads were just slippery enough to
> >
> > allow
> >
> >>>me to shift into 4 high and try it. Does the light get turned on by
> >
> > the
> >
> >>>same vac. switch as the t-case?
> >>>
> >>>Snow...93 XJ
> >>>
> >>>
> >
> >
> >

Where would I find the switch, I haven't looked yet, or is it quite easy to
see?

Snow...

"RoyJ" > wrote in message
news
> Check the connection on the axle before pulling the dash off to get at
> the bulbs. Put it in 4wd, move forward and backward a few feet to help
> drop it in, see if the swich reads close to zero ohms. then see if the
> connector is any good.
>
> Snow wrote:
> > Yeah I'm pretty sure it went fully into 4 high, I turned 4 corners 2 of
> > them slippery the other 2 were dry. I wasn't going fast and the 2
corners
> > that were dry I could feel the front wheels do the "hop" they do when in
4wd
> > on a dry surface. I used to park in an semi underground parking lot, or
> > rather had to drive through one to get to my parking spot and needed 4wd
> > before I entered and after I exited to get into my spot (had turn a
couple
> > corners and the front would hop if it was in 4wd). I haven't checked
the
> > bulb yet, I'll do that tomorrow when I get home from work.
> >
> > Snow...
> >
> > "RoyJ" > wrote in message
> > k.net...
> >
> >>The older YJ's and XJ's had a vacumn switch sitting up on the firewall,
> >>right next to the battery. Switch cuts in only after the front axle is
> >>locked. Newer models have the switch as an intergal part of the diaphram
> >>on the front axle. Cutover was '91 on the YJ, a year or so earlier on
> >>the XJ. You can easily check which you have: old units have 3 vac ports
> >>on the axle, newer ones have 2 vac ports and a wire terminal.
> >>
> >>Did you actually get inot 4wd? Keep in mind that your transfer case can
> >>switch into 4WD, your axle may not have made it. The light does not come
> >>on until it is locked. Usual problem is bad vac harnes, next is the vac
> >>switch on the tranny. Or just the usual assortment of bad wire, bunred
> >>out bulb. Harness runs about $35 at the dealer, switch is about $16.
> >>Lots of guys go with the manual cable, $200 as an accessory, less if you
> >>make your own.
> >>
> >>Snow wrote:
> >>
> >>>Just wondering what turns on and off the 4wd part-time and full-time
> >
> > lights
> >
> >>>on a 93 XJ (4.0, atw4 tranny)? I noticed last night that the
indicator
> >>>lights don't turn on. T-case still shifts and engages into both 4wd
> >
> > drive
> >
> >>>settings, this morning a few local roads were just slippery enough to
> >
> > allow
> >
> >>>me to shift into 4 high and try it. Does the light get turned on by
> >
> > the
> >
> >>>same vac. switch as the t-case?
> >>>
> >>>Snow...93 XJ
> >>>
> >>>
> >
> >
> >

I once did a poll here in this newsgroup. 62% of the readers who responded had
a 4X4 light on their Jeep that malfunctions somehow.