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 > Just wondering what turns on and off the 4wd part-time and full-time lights
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...
Where would I find the switch, I haven't looked yet, or is it quite easy to see?
Snow...
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.
There's a vacuum switch on the xfer case with several hoses coming out of it. They branch off to the vacuum motor on the axle, and a vaccum signal coming from the intake manifol to a harness sorta deal mounted on the firewall by the battery. There's an electrical switch on the axle vacuum motor with one wire on it that goes through to the dash light: I.E., the light comes on once the collar on the axle engages and trips the switch, which grounds the light.
Ther's been several variations on this system over the years (before Jeep finally just dumped it) but they all work essentially the same way.
Mark12211 proclaimed:
...the other poll found that 76% of all statistics are simply made up.
The switch is on top of the transfer case, almost impossible to see, worse to get at. Not sure on the XJ but on the YJ you can pull the shift boot and get a good look at it. It is a cylinder about 2" long with 3 vac ports coming out of it.
You can check the > Where would I find the switch, I haven't looked yet, or is it quite easy to > see?
AFAIK there isn't a transfer case vacuum switch on the 93 XJ: that year there was no vacuum disconnect on the front axle.
That said, the part-time light didn't work on my '93 XJ either, and I was able to determine that the bulb was fine...so it was either in the wiring to the transfer case or (most likely) the electrical switch in the transfer case. I didn't think it was serious enough to mess with unless I had to take the t-case apart for some reason.
my 88 non disconnect has a switch in the tcase that makes the light work. It also has a hard time in 4wd part time. full time works, low works but part time 4wd is iffy for the light even though it shifts well. KH
Ok seams like its just the bulb or wire to the bulb which is bad. Had a couple inches of snow yesterday so too the J**P out and around the neighbourhood tried 4wd hi several times while goosing the gas around corners, wife watched and said that once I managed to get all 4 wheels to spin on a straight stretch when I floored it from a complete stop. If the weather gets nicer over the next couple days I'll look more into the bulb and wiring, if not I'll make a project on the list for next spring. Thanks for all your suggestions.
Snow...
I believe I have read here that the parts stores carry lots of those switches. They are on the tranny and fail lots it would seem.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT'sSnow wrote:
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