Howell TBI

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Hi Bruce, it looks like Red is the signal wire from the selector switch. True?

What are you using for ground?

I love that pump setup, simple and clean.
Ground wire for the pumps and relay is grounded to the frame.

Red wire is pump power coming from the EFI pump relay. EFI controls the power to the fuel pump. It turns ON for a couple of seconds when the key is initially turned on to build fuel pressure. ECM will then power the pump during cranking and while the engine is running. If the engine stalls, the ECM turns OFF the fuel pump power.

OEM selector wire powers the relay coil to select which pump gets powered.

The plate is bolted to the frame with the pumps on top to protect from road trash.
 
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Ground wire for the pumps and relay is grounded to the frame.

Red wire is pump power coming from the EFI pump relay. EFI controls the power to the fuel pump. It turns ON for a couple of seconds when the key is initially turned on to build fuel pressure. ECM will then power the pump during cranking and while the engine is running. If the engine stalls, the ECM turns OFF the fuel pump power.

OEM selector wire powers the relay coil to select which pump gets powered.

The plate is bolted to the frame with the pumps on top to protect from road trash.

Do you remember what type (part number) of the relay you used ?

Thanks,
Fred
 
A USB to RS232 adapter should work, I just used one the other day for a piece of lab equipment.
The earlier EBLs required a USB to serial adapter with a particular chipset. FTDI supplied the chips. Some years back I found a cable at a Fry's or some such and the package label had FTDI in the manufacturer's part number, so I bought it and it's worked fine ever since.

More info here on BobR's archived site:
 
ALL EBLS requires a TTL to USB serial adapter. The newer ones just changed the way the signal is brought out.
And yes FTDI is the way toi go
 
ALL EBLS requires a TTL to USB serial adapter. The newer ones just changed the way the signal is brought out.
And yes FTDI is the way toi go
The cable I have from 13 years ago has a DB9 connector. On BobR's linked page above there's this:
"Note: not required for the EBL Flash-II, EBL P4 and EBL SFI-6 Flash systems. They are supplied with a USB interface."

I don't know if my EBL is the latest/only one used on our GMCs, so I added earlier. If the EBL requiring the DB9 connector is the latest/only one used...why? Is there something about our systems that prevent the use of a later EBL with a USB connector?
 
That 'USB Interface' on the new version is a TTL to USB converter that has a 1/8" stereo jack on the ECM side.
The DB9 on the earlier versions (I'm pretty sure) only uses 3 pins RX/TX/Gnd and is electrically equivalent to the stereo jack, just a different connector
 
They are supplied with a USB interface.
Yeah, that threw me off. It was a farce. the EBL itself is still TTL as Keith mentioned. Mine came with a 1/8" TRS jack that wires into the EBL. Then they supply a USB FTDI cable that has a 1/8" TRS plug on the end. I had lost mine, remembered it being "USB" and started trying to scope out a way to connect "USB" to the EBL. Taking it apart, it became very clear that it was not USB at all inside the EBL. Thankfully I eventually found the USB adapter cable that it comes with.
 
That 'USB Interface' on the new version is a TTL to USB converter that has a 1/8" stereo jack on the ECM side.
The DB9 on the earlier versions (I'm pretty sure) only uses 3 pins RX/TX/Gnd and is electrically equivalent to the stereo jack, just a different connector
Yes, the DB9 version only uses the RX/TX/Gnd pins. In my case, I had to source an FTDI serial to USB cable; because the EBL did not come with one.
 
That 'USB Interface' on the new version is a TTL to USB converter that has a 1/8" stereo jack on the ECM side.
The DB9 on the earlier versions (I'm pretty sure) only uses 3 pins RX/TX/Gnd and is electrically equivalent to the stereo jack, just a different connector
Ah, yes, a RubeG upgrade!

Thanks for the explanation. I no longer have FOHAOFEBL* anxiety.

* Fear Of Having An Outdated EBL
 
"Tip" 'o the hat to you, good Sir. Does that "ring" any bells?
You're 2/3 of the way there; I love that! There I go again, wearing my heart on my SLEEVE. So, for those who care, 1/4" and 1/8" plugs can have 2 (TR), 3 (TRS), or 4 (TRRS) sections. The above photo is a TRS; three silver conducting sections separated by two black insulating sections. The letters stand for tip, ring, and sleeve. Have a nice day!