UNCLEBILL

I have a 1990 Vert but my problem is on my 1988 Formula 350 Firebird (original owner). Installed a ratchet shifter about 16 years ago and only problem was lining up the 2 micro switches for start and back up lites. All went well till a few days ago. It was a dead start...like no power...normally for years I just gave the shifter a little wiggle and it started. Battery is at full power and always connected to a Battery Tender when not in use. All fuses in box are okay. Checked both connectors on micro switches with key on and there was no power reading. Put shifter in reverse with key on and no backup lites. I used a set of clip on wires from a connector on a fuse in the box (was a stereo type clip for power to lite an extra gauge I installed years ago) and was able to get back up lites going but nothing on the start up micro switch. NOTE ...I also installed 2 new micro switches also but that did not help.
Question...can I slip on one of those fuse clips to say the ignition fuse and rewire to my shifter...IS THIS ADVISEABLE as Im lost as to find the root problem.
All replies would be greatly appreciated...

Bill

kg4fku

Not sure how you have this installed so bare with me.

Will the car start in NEUTRAL?

Did you delete the factory PARK/NEUTRAL safety start switch?

Is the shifter making contact with the microswitches in Park and Reverse?

Can you physically manipulate (i.e. push the switches in with your finger) the switches to make the reverse lights come on and enable the car to start?

Are there fuses associated with these switches? Are they blown?

UNCLEBILL

The car will not crank over in either park or neutral....
Too many years ago but the micro switches were just wired to the colour coded wiring diagram supplied of the original wires. This set up has worked well for over 15 years.....
Yes the shifter raised pads are making contact with micro switches......
Yes I did manually try working the switches but no crank up..
There are no fuses associated directly with the micro switches and I did pull and inspect every fuse in the fuse box but none showed they were blown.
This is a hair puller and at 67 years old cant afford any more hair loss

kg4fku

I understand your pain.

Was the car able to start in neutral before this issue?

Not having reverse lights leads me to believe you are not getting power to the switches. That is why I asked if there were fuses.

What I don't know is if these are switched grounds or switched positive circuits.

You obviously understand jumper wires. So can you jumper from one side of the park switch to the other? Basically this should remove or bypass the switch from the circuit. If this works then the switch is probably bad. If it doesn't work then the circuit itself is broken.

That is about as far as I can go without some knowledge of the circuit at hand.

Hopefully someone with knowledge of this will chime in.

kg4fku

I saw you said you replaced both switches too. Seems odd that both switches would go out at the same time.

There has to be something common between them. These are two separate circuits. Then only commonality that I see is the shifter itself and the physical location.

There may be a common power or ground source as well but again I do not have a circuit diagram to go off of.

Has anything been done to the car lately?

UNCLEBILL

I did get power to the back up lites with a jumper wire from a 10 amp fuse but did not work from the same fuse for crank up. With key on I found no power going to either micro switch using my multi meter. It looks like the system for power is gone and that's why I asked for the crank start up can I go to the Ignition fuse and hook up power that way and be safe to the electrical system.No work done to the car previously. Very rarely driven.

Bill

kg4fku

I did some digging for you this morning.


Reverse lights:
There is a fuse for the backup lights. Find that one and make sure it is good. From what I have read it is a 20 amp fuse.

Park/Neutral switch:
Again from what I have read on the third gen forum, there is a green with white strip wire at the gear selector. That wire should have 12 volts on it when the key is in the crank position. If that wire does not have power then the only reason I can see is the PASS key system has failed.

To answer your question about jumping power there from another power source, you will run the risk of damaging something and I cannot tell you what that may or may not be.

Here are some links you may find helpful.

Link for Park / neutral switch
http://www.thirdgen.org/forums/elect...-park-but.html

Link for reverse lights
http://www.austinthirdgen.org/mkport...ody_wiring.gif

Additional link I found that may help.
http://www.thirdgen.org/forums/trans...r-mystery.html

UNCLEBILL

Thanks for the help....MUCH APPRIECIATED
Bill

cohocarl

Don't know if there is any information in this thread that would be useful or not. I bookmarked it a while ago for reference when I get enough time to attempt an install of a B & M Hammer I have.