VSS hookup question
VSS hookup question
What's a poor dumb engine guy to do?
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- Posts: 1696
- Joined: Fri Apr 04, 2008 1:28 pm
Re: VSS hookup question
Some people have had issues with the VSS input, others have not (but we tend not to hear from the people who haven't had issues, of course).
On my 4L60e, I hooked used a twisted pair to the trans for the GPIO, and then use the GPIO speedo output (PT4, PWM1, Amp31) to signal the electronic speedo. You can certainly put a shield on the twisted pair on the VSS wiring if you like, but if you do be sure to ground it only on one end (ground it to the same spot as the GPIO). Keep the VSS wiring away from the coil(s), etc.. This has the best chance of avoiding noise.
However, you can also splice into the GPIO's VSS wires (best to do it near the GPIO itself to minimize the overall length of the wiring) for the speedo. This has a somewhat higher chance of inducing noise in the circuit, but has worked for many users. I did it this way on my car before the speedo output was available in version 2.1xx.
Lance.
Re: VSS hookup question
My vague plan is to run a main ground point on the back of the right cylinder head. Stock setup on this truck is the battery grounds with a strap to the hood hinge on the firewall, then a strap grounds the engine to the firewall. Doesn't sound like a low impedance deal to me, so I'm going to run the battery ground cable directly to a bellhousing or starter bolt. Run a strap to the body and the frame. Ground everything electronic to a bolt on the rear of the right cylinder head with a starlock. The WBO2 wants a 2 grounds, one apparently a power ground to the chassis and a signal ground that will go to the head.
I want to avoid ground loops. Alternate plan was going to run a ground post on the firewall connected to the battery via a factory pigtail off the side terminal batt cable and ground everything to that, skipping the the bolt on the back of the head. This post is on an insulated plastic mount block, doesn't ground on it's own. The engine would be grounded through the neg batt cable, with small ground straps to the body and frame.
The back of the cylinder head is inconvenient, very close to the firewall. A real PITA if any work needed there.
There is a mega-squirt in this deal. I was planning to run all the grounds for it to that ground terminal block too.
Any comments, criticism, upgrades?