CK5
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1981 K20

6" lift. 3/4 ton axles.
Should be wired directly to the pump without a relay.
There were a ton of differing opinions on that subject when I was looking it up. When I first installed I wired direct. But when I added the relay box I went thru a relay. if it comes down to and I have issues I can always change it to direct to pump later.
 
There were a ton of differing opinions on that subject when I was looking it up. When I first installed I wired direct. But when I added the relay box I went thru a relay. if it comes down to and I have issues I can always change it to direct to pump later.

FiTech is very specific about not using a relay because the relay is built into FiTech itself. The only counter argument that I’ve heard is that some high volume aftermarket pumps require a larger gauge wire therefore a new power source is required.
 
Almost got this pig to fire back to life.
Ended up with a tdc whistle and spring indicator. As I suspected (but never fixed) the current balancer is shot/slipped. By a lot.
Made a new mark for tdc. Gonna leave it on the charger and play with it again tomoro.
 
It's way past tomorrow
I haven’t gotten any further than that. It will light off but as soon as I release the key I can hear the starter grinding on the flex plate and it stalls out the engine. (Our atlas that’s my best guess to figure it out).
 
So small update. Put a standard old school starter on it and now the starter action is much better. But still couldn’t get it to stay on.
Figured out that my key switched 12v that showed battery voltage at “key on”, dropped to 1v under cranking.
Ran a jumper from my connection to the efi direct and now it starts up and runs like it should.

nice to be able to clean that side of the garage out.
I need to figure out what is causing the voltage issue so I can finish cleaning up the wiring. And it def doesn’t want to drive great from sitting for so long. Feels like the brakes may be dragging. But getting it able to start is a big kick in the motivation.

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I need some help figuring out this wiring issue.

so my switched 12v wire comes on hot with key, stays hot with key.

no the way it’s run currently, is that is my “switch” feed on a relay, that when turned on, sends battery voltage to a junction block, allowing me to provide Murillo switched 12v sources to various relays.

so when I turn the key on, the relay and everything works correctly, sending the full battery juice to the junction block as it should. But it drops out under cranking.

now the 12v feed wire doesn’t lose voltage since that is what I used to jumper the efi so I know it works as should.

what in the relay setup should I check to find the problem. I can’t figure out what would cause it to work with key on, but not work under cranking, when the key switch 12v doesn’t change.
 
Sounds like your 12v battery source is dropping. Is their a single wire feeding multiple relays/components? What condition is your battery?

I ran into some issues finding a clean source of power for FiTech when I fired it for the first time. I ended up going directly to the battery for the power source and directly to the fuse block for the 12v ignition source. No relays involved until last year when I added a switch panel.
 
Sounds like your 12v battery source is dropping. Is their a single wire feeding multiple relays/components? What condition is your battery?

I ran into some issues finding a clean source of power for FiTech when I fired it for the first time. I ended up going directly to the battery for the power source and directly to the fuse block for the 12v ignition source. No relays involved until last year when I added a switch panel.

that’s what I thought but the battery was staying steady. I’m trying to use it to fire relays for my electric fans.
but those shouldn’t switch on as they’re switched grounds to the relay from the fitech so it should be a massive draw off the bat.
 
Isn't there only certain circuits that stay hot while in the cranking position with the key? I don't know on a square but I ran into this on my little Mazda B3000 work truck. The previous owner had ran a new wire to the fuel pump due to a short but they just used a key on ignition source in the fuse panel but at cranking it would shut off so it was a pain to get started with the fuel pump losing power once you started cranking. I had to troubleshoot the short and ended up just hooking the new wire for the fuel pump to the output from the fuel pump relay and bypassed the factory circuit.
 
that’s what I thought but the battery was staying steady. I’m trying to use it to fire relays for my electric fans.
but those shouldn’t switch on as they’re switched grounds to the relay from the fitech so it should be a massive draw off the bat.

The fans themself don’t come on unless the engine is running IIRC so that should be a non-issue while cranking. What wiring is between the FiTech battery power source and the FiTech?
 
Yeah but the key line is staying hot while cranking so that isn’t the issue

I understand the orange 12v ignition source is ok but I’m asking about the 12v “battery” source (red wire) for the FiTech. You said that’s dropping voltage while cranking at the red wire right? That’s why I’m asking how that’s wired, what’s between the FiTech and the battery? Did you add relays there too?
 
No. The fitech red wire is direct to battery feed (after a 300amp breaker). The fitech wiring isn’t being an issue right now (far as I can tell).
 
I understand the orange 12v ignition source is ok but I’m asking about the 12v “battery” source (red wire) for the FiTech. You said that’s dropping voltage while cranking at the red wire right? That’s why I’m asking how that’s wired, what’s between the FiTech and the battery? Did you add relays there too?
Sorry that earlier answer was for truckmans post not yours. We were posting at the same time so I didn’t see yours til after.
 
So I had her crank while I metered under hood.

under cranking, my 12v switch into the relay is showing 12-12.5. When I plug the relay back into the board, it shows 12v with key on, but as soon as it’s under cranking it drops to nothing.
The battery voltage stays in the 12s both key on and under cranking also.
 
Some pictures of what I’ve been doing. Also some pictures of the Chevy leaving today. And a picture of what I really wanted. Both my new vehicles parked inside at night.

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