Discussion in 'Intermediate CJ-5/6/7/8' started by Jeff Bromberger, Jul 5, 2019.
And here's the cutaway of the valve at rest. Straight outta the DJ-5C manual:
Yeah, it's just a junction block. Serves as a distribution block for the brake tubing and a location for the stoplight switches. If there is a pressure imbalance between the front and rear brakes, it sets off the warning light.
I found a posting referenced in the older AMC forums about how to rebuild it, but the switches on the end seem like maybe they changed things along the way.
If this jeep had the brake light switch on the pedal, that would be one thing. Seeing it on this valve body, well, that's totally another...
Actually, this quite a bit more than "just a junction block". It's a pressure differential switch with parallel brake light switches. Its function is to alert the driver to a brake system failure. In the event of a front or rear brake system failure, the switch detects the failure and completes brake system warning lamp circuit.
What a fun weekend! Well, sorta.
New springs for the front came in. All was going well, but the bushings in the shackles were another story. Now, I am a newbie when it comes to this, and I didn't know that a proper bushing is a tube in a tube with a rubber stuffer thingie in between. I fought the good fight and managed to get the inner tube and the rubber out of the shackle sleeve. The inner tube had rotted/rusted to the bolts, so most of the effort was pulling the decayed rubber out. But I didn't know about the outer tube. No amount of work was getting that one to budge. It is frozen/rotted/welded/whatever to the frame of the Jeep. My solution, partially implemented, was to cut open the new bushings, and then push the new rubber/inner tube into the existing outer tube that's stuck in the Jeep using a lot of dishwashing soap and a huge C clamp. Otherwise, with a new set of Grade 5 bolts, the springs are in place. Axle is still waiting for love and affection from the Hot Rod guys.
Using Tim's advise, I started looking at the bundle of wires kicking around now that there is (technically) no front end on the jeep. I found the Alternator wiring, and how the old Motorola unit used a regulator that's attached to the firewall. That'll be trashed when we get the Delco installed. It is amazing just how simple the whole shebang is - the hardest part are the lights!
So, as I am tracing wires around, I have two items that come to mind. First is this orange wire that was cut (mentioned waaay back in this thread) with a splice going in through a grommet to the back of the dashboard. Second is that happy looking (!) fuse box. I'm debating if I should just go ahead and buy a new wiring harness/fuse box and put it in place instead of the wires I have. My only concern there involves the color schemes and the plug for the ignition switch. All of these generic harnesses seem to have the "GM" wiring colors, but that'll mess up my TSM schematics. Does a sensible harness exist out there that uses Jeep colors? And then, what about that odd shaped plug that is the interface to the ignition switch. Is that part of a wiring harness, or do I have to salvage that out of the existing wires?
And onto that spliced wire... I'm digging under the instrument cluster to get the Sparton turn signal switch out - it is so stiff that it won't move and the rubber wheel needs to be cleaned/reconditioned like a cassette deck pinch roller. So while I an finding the plug at the base of the steering wheel, I look up and see those wires from the splice! Miracle! Trace them back, and they end up in ?the ashtray? The damn thing is rusted shut, so I douse the sides with Liquid Wrench. Finally, manage to get the tray to open and disengage, and there, in amazing glory, is a Radio Shack SPDT toggle switch. It makes sense now...
The old key cylinder was activated by a screwdriver - no key. So the PO must have put in a secret ignition kill switch and hidden it in the ashtray. Pop the switch and there's suddenly no primary power to the ignition coil, and Jeep magically won't start.
If I choose to put that added function back, it won't be hidden in the ashtray this time.
FWIW: I just ordered the Brake Warning rebuild kit from Muscle Car Research, and the two Stop Light switches from Amazon. I still need to get replacement contacts for my wiring harness, but I can probably wing that if I have to.
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