Questions about things mounted to the firewall.

I'll get right to it: 89 RCSB 4.3L 5-speed, everyone knows that. I had to tear just about EVERYTHING off of the firewall for a repair I was making.

So first question: There's a fuse/wiring panel attached to the firewall, just above where the A/C core would be on the passenger side. What does it go to? Mine is rusted so I'm going to have to clean it. There's also some relays and a small fuse in that same panel. Where's all that go to?

Second question: Since the clutch slave cylinder is attached to the firewall, that's why this question is here. If I press the clutch in, it's firm and does it's job. Releasing the clutch pedal, however, it comes up very slow and grabs just as slow. I get that you're supposed to let the clutch pedal up easy sometimes, but this is slow almost like something is holding it back.

I would provide pics, however, I don't have any means to do that at the moment.

Any ideas?

Fusible links/power distribution block for basically the entire truck. Check a wiring diagram in the service manual under "convenience center"

The relay is your fuel pump relay; fuse is the fuel pump fuse.

Be careful cleaning up in there. Don't want to touch one of those terminals with a metal tool then short across it and do any unexpected welding.

Clutch situation sounds like some wear and tear.. the clutch fork ball stud is a known trouble spot on the older style bellhousing but I really can't recall what setup the early light duty 5 speed is; haven't personally owned any except for a handful of parts trucks. Someone else should be able to chime in there.

Richard

DeCaff2007 said:

There's a fuse/wiring panel attached to the firewall, just above where the A/C core would be on the passenger side. What does it go to? Mine is rusted so I'm going to have to clean it. There's also some relays and a small fuse in that same panel. Where's all that go to?

Click to expand...

That's your power distribution block. It's fed directly from the battery with the smaller wire. All of the terminals are hot at all times. They feed your ignition switch, your fuse block inside the cab left of, and below the steering wheel, the fuel pump relay (red arrow). A lot of those wires have fusible links for protection.

Be careful with that block, disconnect the battery before you mess with it.

Edit: I was writing this when Richard answered your post but, here's a picture of my 88's block and relay.

Ok see that red wire coming off of the right most lug in the pic? The in-line fuse holder at the end of that wire was completely corroded and fuse inside was hanging on by a thread.

There's been no battery in this truck for quite some time, so I'm not worried about shorting anything.

Two different trucks 1 year apart if this helps

I do appreciate the replies. I need to go grab a replacement fuse holder, clean those terminals, and I'm pretty sure I have spare glass fuses laying around.

Now to address the second question: What's up with my clutch?

Check the spring on the clutch pedal itself

94K3500PROJECT said:

Check the spring on the clutch pedal itself

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When I get home from work today, I'll do just that. Sadly, I didn't even know there was a spring down there.

You can always wrap a bungee cord around the back of the pedal and up over the steering column. Old farm truck trick for dragging brakes or broken clutch spring.

Well, here's the skinny: I just put a drivers side floor pan and frame mounts on the cab. To do this, it required stripping down the firewall so as to be able to move the cab off of the frame and get everything done.

Now that the cab is sitting on 4 brand new polyurethane mounts and decent frame brackets, it's time re-assemble the junk on the firewall.

Granted, before I even started this project, the clutch pedal was not right.

But, now that I have a direction to go in, I'll update this as I find things out.