Going to try my luck in the Carb section since this deals with a possible fuel relay, I think this is the appropriate place

I'm rebuilding my L69 and I'm at the stage of redoing my wiring and adding some fancy wire looms. When I took the plastic looms off I found a few relays had gotten very hot and/or spliced into.:

I'm looking at the factory service manual and have been able to figure out (I think) what most of the relays near the brake booster are.

Here's a picture


If anyone could enlighten me on which relay is which and make sure I marked these correct, I would greatly appreciate the help.

Also, what does a Throttle Kicker Relay do?

One more image

 

Does anyone have a picture of their factory L69 relay setup?

 

From first picture what original part numbers are printed on the side of your relay? Sometime you can search using them and/or get ideas from napa or a wells parts catalog.

 

They come up as a plethora of different universal relays: A/C, Fuel Pump, Fans, etc

They are all interchangable

 

I am not sure which is which but your car DOES have all 3 of those things. Fan, A/C and electric fuel pump.

Even though the L69 was a carbureted engine GM installed a low pressure electric "helper" pump in the fuel tank on 3rd gen F-bodies (looks similar to an EFI in-tank pump but much lower pressure).

The A/C kicker is the cylindrical solenoid on the front/driver's side of the carb that bumps up the idle speed slightly when you engage the A/C, to compensate for the added load on the engine at idle from the A/C compressor.

Probably doesn't answer everything for you, but hopefully it helps a little.

 

The relay in question is definitely the fuel pump relay. Starter > Oil Pressure Sending Unit > Relay. It's getting replaced with a Painless Wiring relay, including both LS1 Fans.

But as far as the "Throttle Kicker Relay" goes, the factory service manual says that it is indeed a throttle kicker relay. Granted I havn't been home to check that relay out in particular, but does it send a signal to the solenoid on the carb?

 

I spent a lot more time tracing wires tonight. In my opinion, the wire is all F-ed up. Everything works, but I hate the way it looks.

I'm not a noob when it comes to wiring. I work avionics on F-15 Eagles, but this is driving me crazy.

This is more or less me just venting.....

 

here's a pic of my relay setup, hope it helps.

 

Where is your fuel pump relay?

 

I feel your pain. My brother (who fixed electronics in the big ICBMs for the Air Force) gets all twitchy trying to diagnose a hacked-up 3rd gen harness. Nobody rewires the harness on an F-15 because they can't trace a ground or because they want to add an aftermarket stereo to it. Military applications exist in a much more controlled environment. Out here in "bubba-land" you gotta roll with the punches, my friend.

You must learn to think like a HACK, grashopper! Think like somebody who doesn't know what they are doing. Impossible to unlearn everything you have learned you say? No, sir! I say you can. As long as you think like an untrained monkey.

What do untrained monkeys know? They know four things, primarily:

1. If the wire is "hot" when they need it to be, they use it. Forget whether the circuit can support the load or not- it gets hooked up.

2. They don't know what a ground is or why it is important. Therefore, they get ignored and often left unconnected.

3. Physical proximity seems to be emotionally comforting to them. If what they need is physically close to where they need the power, they tap into it.

4. All wires that share the same connector on the end are interchangable with eachother. If it can plug in somewhere, that's where it gets plugged.

I can hear you laughing on the other end of the internet from here. Yes, it's kinda funny but it's also usually true. Once you can visualize how somebody would have hacked up the harness in an attempt to suit their needs you can undo the damage they have done. Once you have it back to stock operating condition THEN you can begin the process of diagnosing any real underlying problems (following factory manuals and wiring schematics). LAST comes PROPER modification of the harness to support aftermarket products you may wish to add to the car.

Experience tells me that 80% of your time will be spent figuring out how to "un-hack" the wiring harness. Doing PROPER modifications to it after that will be a breeze in large part because you have already become intimately familiar with the wiring in the process of repairing it!

You can laugh at me if you want. It's OK. I've got broad shoulders. And more years fixing other people's botched-up modifications than I care to admit. I guess what I'm saying is "trust me" on these little bits of wisdom. It ain't right, it ain't proper, but it's how things usually are out here in the world of the electronically illiterate.

 

You're right, I was actually laughing at this.
80%? Pft, more like 95% I finally got the engine out last night so I have full access to all the wires.
I'm still trying to figure out how a dealership would have routed the wires when they installed a pusher pump. I have nothing coming from under the car, but I do have a grey wire coming in from the interior above the steering column (I havn't had time to take a look on the inside though).

I can figure out what does what, but I have relays that are connected to other relays; kind of what a hacked dual fan job would look like if you wanted both to turn on at the same time.

All-in-all though, I'm replacing all underhood relays with Painless products (fuel pump, fans, AC compressor). I would be modifying the original harness to my dismay, but in the end I think it's a better choice.

 

Well I finally figured it out.

What I thought was the fan relay is actually the throttle kicker.

Fan relay = Throttle kicker
Throttle Kicker = Fan relay
???? = Fuel pump relay

Like I said before, the wiring is a complete mess save for the throttle kicker (done so by the dealer when the pusher pump was installed). Hopefully this will help someone else down the road.

 

There you go! I knew you could figure it out. I'm guessing this little mystery ate at you until your bio-computer figured it out.

I haven't met a military-trained electrical tech yet that isn't a meticulous bastard with a never-quit attitude.

Congrats and thanks for your service keeping the Eagles soaring.

 

Haha. Go brain and wiring diagrams!

Thank you very much for the kind words