Daves03

okay, my speedometer and odometer gauges do not work, i tested everything from a wiring diagram that i had sent to me by someone on here, i have a new vss in the transmission, i removed it and double checked the gear inside, the gears are fine, the purple and yellow wires running down to the transmission from the speed buffer box are supposed to have 1-5 volts ac, i tested the wires and i am not getting the voltage require while spinning rear wheels, i ohm'ed the wiring, the yellow wire has 0.1 ohms, good, the purple wire however when tested starts a 20 ohms and keeps rising the longer you hold the ohmmeter to the wiring, i know i have a broken wire or grounded wire, could someone please tell me where the rub points are and how the wi
re is routed, what its routed through, i know it runs up the transmission somewhere around the firewall and up into the bulkhead connector but is this the only place it goes?
the wiring schematics i followed are these
https://www.thirdgen.org/forums/atta...tbispeedoa.jpg

https://www.thirdgen.org/forums/atta...tbispeedob.jpg

The car is a 1991 chevrolet camaro RS 305 V-8 automatic

Fullsizewagon

Well, you found the problem, and there's nothing between the two connectors you're measuring at except the bulkhead connector. You'll just have to inspect the purple wire all the way, and maybe try to measure it at the bulkhead connector too.
I gather you measured across (over) the wires and not relative to ground.

Daves03

no i didnt measure from purple to ground but that is a great idea didnt even think of that, ill test it, thanks for the info. i didnt know if it just ran through the bulkhead and that was all or if it ran through the bulkhead over here and there and connected or what. Thank you.

Daves03

ok i measured the resistance from the purple to the ground on the cigarette lighter and im getting about 2.4M ohms, i disconnected the bulkhead module connector c100 and searched on here for a pinout, thanks to xomega i now have a pinout of my c100 connector.
http://img208.imageshack.us/img208/8...ulkhead2eg.jpg
http://img208.imageshack.us/img208/1...dpinout8bq.jpg

found that terminal E4 in my engine harness is carrying the problem, tested from the speed sensor buffer box up to the cavity in the firewall and i am getting 0.3 ohms reading which could amount for general motors snazzy black gloop on the terminals, thank goodness my problem dosent lie under that stupid dash, now i just need to check around the back of the engine and down for any smashed wiring or problems, the purple wire is probably shiscabobed on a bolt somewhere, i will keep in touch and let you know what the outcomes are, as for the wiring here is some that may aid others in repairing there speedo.

Fullsizewagon

Yes, that 2.4M Ohms does reveal there's some chafing and/or corrosion somewhere.
The 0.3 Ohms I guess is just the usual inherent minimum reading of the instrument.
You seem capable & unafraid so I'm sure you'll find this easily.

Daves03

found connector bad on the vss, the wiring harness was pulled so tightly over the connector that the wires were bent at a 90 degree angle therefore breaking internally, straightend the connection out and tested .1 ohms, tested the wiring bent and the meter reads O.FL or open, clipped the connector off and took it to work with me and repaired the terminals and added some length to the wires, installed back onto car, still no speedometer, lifted rear wheels to check for 1-5 volts ac on the buffer box, signal is still not reaching the buffer box, believe to have a bad vehicle speed sensor, just replaced the sensor but it came from advance auto parts and i have had bad electrical parts from them before right out of the box, just have to wait untill tomorrow and see what happens when it comes in.

Daves03

ok so here is the wrapup, the damaged wiring at the vss connector repaired, wiring is ohming good, tested car, car speedometer test failed, checked over the troubleshooting guide listed in this thread, all signs point to a bad vss, the speed seensor however was replaced less than 2 years ago and did not work back then, took the speed sensor out and back to where i bought it at advance auto parts, now im not putting anyone down at advance but they do have a lot of bad luck with electrical parts, got the new speed sensor ordered and swapped the defective one, popped the new sensor in and tested, the speedometer is now reading, the odometer and trip are working fine, the transmission for the first time i have owned the car has shifted into overdrive, i hope this thread and troubleshooting process helps many of the technicians on this page to diagnose there speedo's, THANK YOU TO ALL OF THE MEMBERS OF BROTHERS AND SISTERS ON HERE for all of your help and this page to help people drive the legendary muscle cars and keep them running at full potential. ONCE AGAIN DO NOT TRUST THE PARTS STORE TO SELL YOU GOOD PARTS IT CAN LEAD TO YOU TEARING 3/4 OF THE CAR APART AND YOU DONT HAVE TO.

Fullsizewagon

Glad you found the faults and got it working again!
Thanks also for posting the final results (not everyone bothers to do that).

Daves03

no problem its cool i hope this thread helps more people, once again thanks to the thirdgen.org family its nice to have a family who cares so much.