Basic Maintenance--Ignition switch
It's a long story about how I figured my Ignition switch to be bad, and it was part of 3 other simultaneous problems that left the Jeep D-E-D in the parking lot one day. I can get to that later, but lets look at replacing the Ignition switch.
The problem I encountered was that my fuel pump would not get juice in the "run" position, it would only get juice in the "start" position.
The Ignition switch itself is not the thing you put the key into and turn, that is the lock cylinder. The Ignition Switch proper is an assembly on top of the steering column, under the dash. There is a metal rod that runs to it that is actuated by turning the key in the lock. This is the switch, you can see the ignition wires coming out of it--viewed from under the dash, from the passenger side of the steering column.
This is the switch after you drop down the steering column. You can see the rod coming from above that goes into it, I'm touching it with a screwdriver tip. This is directly on top of the steering column, under the dash.
Screwdriver here is directly poking on the upper part of the Ignition switch.
There are some differences between switches in the Non tilt column, versus the Tilt column, and they have different part numbers. Mine is the Tilt column, so yours will vary depending on style column. There are also some differences in the procedure of function checks and adjusting based on manual versus auto tranny. Mine is a 5 speed.
First thing to do of course in any electrical work is to disconnect your battery, block your tires etc. Leave your KEY in the OFF position. You need to remove the instrument panel bezel, there are 4 screws across the top above the speedo/tach, and two below. Once you pull these off, you need to drop the steering column. There are 2 bolts, 5/8 head, one on each side of the column, remove these.
In addition, you should remove the 4 bolts that hold this bracket to the column. Two on each side, 13mm or 1/2 inch fits. You can see them in the above photo, you can then remove the bracket and set it aside. Next you should remove the 13mm head bolts holding the plate that supports the steering column at the firewall. There is a foam type grommet that is visible on the engine side, I just pulled it loose with the plate.
This will allow the column to drop down so you can access the Ignition switch. The high beam switch is closely associated with the ignition switch, it shares mounting points. In addition there is an actuator rod coming down from above that fits into a socket on the end of the high beam switch, shown below.
High beam switch, seen from passenger side of column, from beneath.
High beam switch and actuator rod--lower center of photo, with ignition switch directly above it.
High beam switch supported by my grubby thumb.
The actuator rod for high beam switch goes into the socket just above the screwdriver tip.
To remove the Ignition Switch and the High beam switch, you need to remove two fasteners--as shown at the end of the screwdriver.
Removing these will allow you to remove the High Beam switch, then the second fastener has another nut to remove that pulls out the final stud holding in the Ignition switch.
You can now pull it free from its own actuator rod, and it will dangle from the electrical cables.
The actuator rod looks like this now, on top of the steering column. This is important of course and will play a role in a bit.
To remove the two connectors from the switch, there are 4 tabs to depress, one blue one here:
And the other 3 here, 1 more blue, and 2 black:
Depress the tabs and you can remove the plugs from their sockets.
Now to look at the old switch and new switch for comparisons.
The next part is the reassembly. Since this is a multi-position switch, when you reassemble it, the switch going back in needs to be in the same "position" as the original. Since you left your key in the OFF position (right?) your new switch needs to be in the same off position. Photos help. The "tunnel" I have a broom straw going thru is the hole that the actuator rod goes into.
You can see the hole a bit better here:
So compare your old one to the new, one of these things is not like the other....... I have the two switches stacked on top of each other, the new one on top has the tunnel all the way to the right (ACC position), while the original is back one click.
Adjust your new one by sliding it back a click with something like a screwdriver tip, taking caution not to ratchet it back way too far, as it can slide over an inch in its various action positions. You can see they are now in the same position. May have to use your imagination a bit as the photo doesn't really show it so well, but compare the last few photos.
Now you can install the new one, the actuator rod goes into this tunnel, you reattach the electrical plugs in the sockets. Those two separate plugs actually have to "mate" together, interlocking, so they can be then installed simultaneously. Then you reconnect your fasteners remembering to put the actuator rod back into the High Beam switch and connecting that switch then to the same fasteners as the Ignition switch.
New Ignition switch and actuator rod, going together....
Once you have this reassembled, you can reconnect your battery and test for function. If your switch is slid too far down the column in its elliptical mount holes, it may need to be adjusted back up the column a bit to achieve the full range of functions. It sounds complex, but actually when you see it, it will make sense. Once you have the function check completed, then reassemble the column/dash, etc.
My particular problem was that my fuel pump would only get power in the start position, but not in the run position, so the motor would die. It wasn't just the simple problem of having a bad relay, swap out the fuel pump relay with the horn relay and you're back in business--the problem was a bit more sinister since I would only get power down the line in the start position, while in the run position, it was cold. For whatever reason, the contacts inside the switch went bad. Once I replaced the switch, all was fine. Hope this helps.
When you reattach your steering column, check on the engine side to make sure you haven't pulled your steering shaft apart.........that would be bad.
Let me know if you have any questions. :thumbsup:
Great write up. Thank you for the information.
Once I catch up on a few other things, I'll try to post up a pin out of the switch, etc. Having the Jeep down this weekend sort of ate up all of my discretionary time.
This is great Opihi, I wish I had this writeup when I had to replace mine, it was a total PITA, I managed to do it without lowering the column, but I have small hands. This may sound crazy but I removed the front seat so I could lay flat on the tub under the dash, I was able to clean up the rat's nest under the dash a little bit, my Jeep PO's really managed to hack and slash the original wiring in a really stupid fashion... :brickwall
I do have one question, what happens to the steering column bearing on the other side of the firewall, does that stay in place or do you have to disassemble anything on the engine bay side?
Hope my question makes sense, and thanks again for a great job, this should be added to the FAQ :cheers2:
Didn't have to disconnect the lower bearing on the steering column. Pulling out that plate at the firewall after pulling out the upper support bracket really lets the whole thing drop down so I could get to the Ign switch for both adequate photos and my mongo-large hands. There was so much free motion in the column that I was worried I had disconnected the steering shaft somehow, but a quick check before and again after the reassembly showed it all to be intact.
The fuel pump being powered only while in the "start" condition sounds like a bad ASD (Auto Shut Down) relay.
Excellent as always!
I agree Max, as the ASD and the fuel pump relay are linked/jumpered to each other in the PDC, and I was very suspicious of that as I dug into the wiring diagrams and the actual wiring in the Jeep, but both of them (relays) checked out when I tested them and when I sequentially rotated them to the horn relay site. I'm planning on powering up the old Ign switch and testing each pin in various positions for a final confirmation when I get the chance. I was happy enough though testing it while it was still in the Jeep and finding that it wasn't "connecting" and giving me continuity across the circuit in the run position. Glad that it is back and running now with the new Ign switch in. Thanks Max. :wave:
I recently had a '93 YJ 4.0L come through the shop with this very issue, along with shutting off while driving down the road. It was a long road to finding the culprit, but in the end it is finally exorcised of it's demons.
It turned out to be the main harness connector that bolts to the backside of the underdash fuse panel on this particular Jeep. Flexing the harness/connector area by hand would produce/relieve the condition reliably. I unbolted the connector & thoroughly cleaned/greased the terminals to improve the connection. Before bolting it back together, I gave the male terminal ends a slight twist/bend for a tighter fit.
This of course may not be your issue, but I documented it here hoping that someone may benefit from my own experience.
I had several other simultaneous issues going on, but all fixed now. Jeep is back on the road for me to enjoy until it does the next Jeep thing for me to figure out.
Jeep doing fine, I just wanted to post back in as I had mentioned I was going to trace out continuity in the switch. I couldn't reliably re-create what I was experiencing and didn't have enought hands to hold back spring tension and get 2 probes in there so I gave up on that. Suffice it to say the switch was shot, I put in a new one and I'm back in action again.
Thanks Opihi. This is one of these things that could cost a person a lot, just to trouble shoot and find, and is rarely covered in the manner in which you are presenting. Good stuff.
Dude Opihi, this will be very helpful when I get into replacing my switch back to orig.state. the previous owner hardwired a keyed boat switch into my 94 yj.thanks for all your efforts in doing this.
I'm glad that it is beneficial to our Forum.
How much was the replacement switch?
|The time now is 12:14 AM.|
Powered by vBulletin Version 3.8.8
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.