redflash1800

Posted this earlier, without successful resolution. Although I received many suggestions and helpful advice, still no good. Please bear with me.



ECM diagnostic = 12 – no other codes are indicated. Continues to flash 1 then 2 on the dash.

(Unexpected & not documented anywhere I saw - The radiator cooling fan runs when the A & B terminals are bridged with the ignition switch in the on/run position)

A fused jumper was used on the connector terminals of the green/white & purple wire of the park/neutral switch. The park/neutral safety switch tests okay.

A small measure of success…
Used the voltmeter between the small terminal (PPL) of the solenoid and ground. Zero volts when ignition is in the start or on/run position. Good so far…

Switched the ignition switch to the on/run position and jumped the solenoid between the 2 terminals. The car starts and runs fine. All exterior and interior lights, wipers, power windows, etc operate and the car is drivable. Turn off the ignition and she will not crank/restart again. Only way to get it going again is to jump the terminals at the solenoid.

Security System / Door Locks
Found something here that seems unusual, however, not sure why this may be occurring or if it could be why the car won’t crank.

Power Locks
Using the power door locks inside the car, both doors lock and the SECURITY light on the dash stops flashing. The alarm system arms and the horn sounds on/off when the doors are opened without the key. Used the key on the driver’s door and the horn stops sounding. The car still does not crank, however.

Manual Locks
Using the manual door locks inside the car, both doors lock, but the
SECURITY light does not stop flashing. The alarm system does not arm. The car could be entered / stolen as the alarm does not operate (if the car could be started – sigh).

I’m ready to check the starter enable relay, but not sure where it is
located. Not much left to check.

Items inspected and tested
- Battery - Fully charged, terminals clean and tight
- Wiring – All terminals are clean and tight
- Fuses - All fuses are good, including the crank fuse on firewall
- Starter – Functional only when jumpered at solenoid
- Park/neutral switch - Checks out okay
- Ignition keys - Tried both ignition keys, also checked resistance of
keys resistor-both provide same resistance readings.

Items not inspected or tested - looks like some weekend work, I'm afraid.
- Ignition switch - Not checked… yet
- Starter enable relay - Not checked… yet
- Fusible links - Not checked… yet


Questions...
Could the ignition switch be bad if the car can be jumpered, started and
runs?

Where is the starter enable relay physically located?

What's with those door locks? Could that be the cause of the problem?

Once again, thanks in advance to those of you who enjoy these challenges. By the way, I ordered a Helm's manual yesterday. Hard to fix these things without the right tools, so to speak.



Here's the orginal posting, which explains the "no crank" condition of my 89 Vette...

My tale of woe.
The goods:
'89 vette, 350 v8, automatic tranny, 80,k miles.

The woe:
Tried to start her, turned the key & nothing. Tried again and voila, she cranked, started and ran fine. Got her home in the garage and tried again. No good! No crank, not even the dreaded "clicking solenoid" of doom!

Troubleshooting efforts:
Battery checked out okay, but I put it on charge anyway, just to try to eliminate potential causes. All the gauges, headlights, turn signals, wipers work okay, so I believe I'm okay in the battery department. The battery voltage & amperage appear to be within normal ranges too.

Checked the battery connections. Both terminals are clean and physically & electrically tight. The solenoid terminals were also clean and tight. Wiring from the battery and solenoid is in good condition.

Shifted the automatic transmission into neutral and tried - no good.
Tried to crank her over in park, neutral, reverse and drive, just to see if the park/neutral safety switch could be the culprit. No good.

Tried both ignition keys, cleaned them both with rubbing alcohol to ensure the VATS resistor contacts were clean. Still no good.

Lubed the ignition switch with powdered graphite lubricant just to see if this was the cause... and, it wasn't!

Looks like I'm going to have to roll up my sleeves and really dig in to resolve this one. Before I get too far ahead of myself, I wanted to see if anyone else has had any experience with this problem. Any assistance would be greatly appreciated.

Thanks,

Jim

Draven

Just a note, my '91 factory alarm system behaves the same way with the manual / power door locks and alarm. If you lock it manually, the alarm doesn't arm. If you lock it with the power lock buttons, it does arm and will go off.

Otherwise, I have no other recommendations. I think most people will chime in with VATS advice though.

Hooked on Vettes

The fans will run because you have Pin A and B shorted. That's normal.

12 volts should be on the Dark Green/White wire on the Neutral safety switch when you have the key in the Start position.

When the ignition switch is in Start, the Yellow wire from the ignition switch should have 12 volts on it.

The Yellow wire is used to power the Primary of the Starter Enable Relay Coil and also provides 12 volts to the Neutral Safety switch when the Starter Enable Relay closes.

When you insert the key in the ignition cylinder and turn the ignition on, the Security light should go out. The Pass Key decoder Module will ground the Primary coil of the Starter Enable Relay. The relay closes and passes the 12 volts from the Yellow wire thru the relay to the Dark Green Wire of the Neutral Safety switch.

You need to measure the voltages at the Starter Enable Relay.

The Relay is located behind the Center Multi use center.

Remove the plastic bezel that covers the radio and DIC area.

Disconnect the electrical plug for the horns (front frame rail area) so they don't sound.

Then press the horn and you'll hear the horn relay click.
The Starter Enable Relay is next to the Horn Relay.

The Starter Enable Relay has 4 wires. My 89 schematic isn't very legible but it appears the Pass Key Decoder module grounds a Dark Green wire which closes the Relay.

At the Starter Enable Relay, there are 2 Yellow wires which should have 12 volts on them when the ignition is in the Start position. When the Pass Key Decoder Module grounds the Dark Green wire, 12 volts from one of the yellow wires passes thru the relay to the Dark Green/White wire which goes to the Neutral Safety Switch.

So your problem is no 12 volts from the Yellow wire of the ignition switch, a bad Starter Enable Relay, poor connections at the Starter Enable Relay socket or bad Pass Key Decoder Module.

jfb

First, jump the gear selector safety switch and try a crank. If it cranks, defective gear selector safety switch. Measure the voltage on your jumper to ground, it should measure 12v when you hit crank position, if not, the start enable relay is not closed. The relay could be defective, but not very likely. More likely, you have a worn ign tumbler which has contacts in it that make connection to the key pellet. Remove the kick panel above the drivers feet and find the two wires that come out above the steering column and go to a 2 pin connector. Insert your key in the ign, unplug the 2 pin connector and measure the resistance across the wires from the steering column (these go to the ign tumbler contacts and the pellet). It should measure the same as the pellet resistance and if over 13k ohms, you need a new ign tumbler which will have new contacts. You can temporarily bypass VATS by clipping a resistor the same value as the pellet across the 2 pin connector on the wiring harness wires (goes to the VATS module). A 1/4 watt 5% resistor from Radio Shack will work, but the actual resistance must be within 1% of your pellet resistance, so you may have to try several resistors or connect several resistors in series or parallel to get the correct value. Don't permanently bypass VATS because 99% of thefts are done by bashing the column and jumping the ignition.

redflash1800

Spent the night in the garage and really rolled up my sleeves on this "no crank" problem.

Got the VOM out and started to check voltage & continuity of the starting circuit.

Reaching the starter enable relay required dismantling of the center console and the "multi-user" cover. Tucked behind this was the starter enable relay.

Metering all 4 terminals was revealing. There are only have .73 volts (< 1 volt) to the +12 v terminals. There is not enough current to engage the relay needed to crank her over.

The starter enable relay checked out fine. There is continuity through the relay coil, which should engage the relay contacts when powered with +12 volts. The relay contacts, when manually activated, also enabled continuity of the circuit. So, I should be in good shape there.

The park/neutral safety switch checks out fine too. Continuity is achieved when placing the switch in the neutral and park positions. Any other position, e.g., drive or reverse does not permit continuity of the circuit. Jumpering between the purple wire, which connects to the solenoid and to the wiring to the starter enable relay does not enable cranking.

So... that leaves me with the ignition switch! Started to pull the wheel, but I don't have a steering wheel puller. I will have one tomorrow after a trip to the auto parts store.

My hunch (thanks also to jfb for his advice) now leads me to believe it is a worn ignition tumbler or something related to the key switch.

Anyone have any suggestions or comments on replacing the switch? I don't have my Helms manual yet so I'm going in blind, so to speak. Perhaps some tips or hints that may keep me from getting whacked in the head with a spring or something that will pop out from the column as I'm yanking on the wheel.

Thanks again for all the advice and I'll loop back to let you know when we've achieved success. At least I'll document this experience well for the next poor chap who finds himself scratching his head one fine summer day when his Vette won't crank.

Jim

Hooked on Vettes

When you did the measurement for the 12 volts on the Yellow wires, you do realize the ignition key must be turned to the Start position?

If so, to verify why you're not getting 12 volts to the Starter Enable Relay, (which could be a mis-adjusted ignition switch or bad ignition switch it's easier to pull the whole steering column.

The 12 volts you're missing comes from the ignition switch not the ignition key cylinder.

The ignition cylinder moves a rod that goes down to the ignition switch. The ignition switch has a small amount of adjusment for the detent positions.

To remove the column.
Disconnect the negative battery terminal.
Remove the plastic panel with the footwell lamp.
Remove the carpet panel below the steering column.
Remove the bolt under the hood where the steering column attaches to the steering shaft.
Inside the car, remove I believe it's three nuts from the plate that bolts the steering column to the fire wall. You may have to pull the carpeting back to see the bolts.
Remove the 2 bolts holding the steering column bracket to the dash.
The steering column will drop down so let the steering wheel rest on the seat cushion.
Now look at the top/center of the steering column and you'll see the ignition switch. You need to disconnect the harness from the ignition switch and I believe about 4 other electrical connectors and then you can pull the whole steering column out of the car.

AGENT 86

http://members.shaw.ca/agent86/Steering%20Column.pdf

IRAraid

My '95 had a 'sticky' ignition tumbler that made the key difficult to extract. So I shot powdered graphite into the tumbler. Key inserts and extracts very easily now.
The next day, the car won't crank. After much agony, traced it to the VATS system. The key measured the correct resistance but the car wasn't seeing the correct value. Then like lighting "the graphite had contaminated the cylinder."
We had foam covered swabs (in the video lab where I used to work) for cleaning video heads. The foam cover avoids getting the fibers from common swabs into the works. The swab wouldn't quite reach into the tumbler but a foam ear plug did nicely. Came out black. After several cleanings (making sure to avoid pushing the ear plug in so far as to get stuck) the car CRANKED.
Couple of days later, no crank. Of course there were several ear plugs in the car by then and one cleaning later and with the 7 minute or so wait for the VATS to reset, the car started.
Now carry several ear plugs and a set of VATS resistors in case the ear plug cleaning doesn't work.
Sorry for the windy reply but this was such a PITA to find and so easy to fix, just had to share.
Hope you crank.
PS The VATS is easy to bypass, use the search tab or ask again.

Hooked on Vettes

It's simple to tell if the Key Pellet is being read properly. Turn the ignition on. The Security light should come on for a second then go off. If the light stays on, the engine won't crank. It's that simple.

The poster has mentioned there is no 12 volts on the Yellow wires going to the Starter Enable Relay. The missing 12 volts has nothing to do with Vats.

IRAraid

Recognizing that there are significant dash wiring differences between a '95 and '94 (like the location of the starter enable relay), in a '95 there is a 'crank' fuse located in the dash panel just inside the passenger door. It's #10 and is a 5 amp fuse. When it's blown the car won't crank.
The '95 wiring diagram shows the 12v progressing from the large fuse panel behind the battery, to the ignition switch, to 'crank' fuse #10, then to the auto shift selector, then to the starter enable relay pull-in coil, then (via the VATS logic switch) to ground.
Perhaps I missed it in this thread, but is there a #10 crank fuse in a '94 and is it good? It it's blown, there would be no voltage to the shift selector switch or the yellow wire at the starter enable relay.
BTW, the Helms manual shows the fuse #10 in the diagrams but omits it from the no crank diagnostic table.
Great info on how easy it is to drop the column and find the ignition switch separate from the tumbler.

scorp508

Your manual door lock description is correct. The alarm does not arm if you just slide the locks to locked position.

Hooked on Vettes

In the title of his post he say's he is working on a 89.
At least I hope he is.

IRAraid

:o
My apology for the confusion. Reading glasses now required at the computer.
Does an ’89 have a crank fuse? Perhaps behind the DIC?

BTW a similar thread is running at
http://forums.corvetteforum.com/show....php?t=1427614

redflash1800

The latest offering in this continuing saga.

Pulled the steering wheel and checked the key switch, just to make sure that little bugger wasn't the "no start" culprit. It wasn't..sigh! The key measures 9.4 ohms across the key pellet resistor, which is the same as the the two wires that come out above the steering column and go to the 2 pin connector. Good electrical continuity is present when the key switch is moved to start position.

Guess that leaves the ignition switch as just about the only item I have not checked out.

Thanks again to everyone who has offered their suggestions and advice. Sure helps to have the collective voice of experience to help out.

And, on the bright side, I've gotten much more familiar with the Corvette starting system, dash, safety switches, relays than before. And I got a new steering wheel puller too!

Once I get this going, I'll be quite the expert at this, so I'll be able to help the next "no start" guy.

Thanks again,

Jim

redflash1800

That was it. For 17 bucks I replaced the ignition switch and she fired right up. Ta da!

Had an opportunity to do some other stuff while I had the steering column pulled. Cleaned up quite a mess the previous owner left me. An abandoned after market alarm that looked like it was wired by a color blind 10 year old. Red wires to green wires to yellow wires. You get the idea.

While I was doing all this work, I took plenty of photos of the ignition switch, starter enable relay, park/neutral safety switch, etc. Holler if anyone needs photos of this stuff.

Once again, thanks to everyone who pitched in and helped me get her back on the road.

Jim

Hooked on Vettes

Most people would have given up and taken it to the repair shop.

Did you actually pull the column out of the vehicle to work on it or just drop it down?

.

rick lambert

perseverance and a little help goes along way.And thanks for letting us know the out come, wish all members would post their find.

redflash1800

I could have given up and taken it to the local garage, but I was determined to fix this myself. So, I pulled the column, which was fairly easy and straightforward. Just a few bolts, screws, connectors, etc and she came right out.

Had to buy a steering wheel puller and lock plate depressor, but one can never have too many tools.

After replacing the ignition switch, the only minor tweak I had to make was to the high beam switch, which required me to stuff my head way up under with a 10 mm wrench

While I was at it, I took the opportunity to check the key switch and other wear items while I was in the column. All looked to be in good condition.

Also installed a new Alpine stereo while I had the instrument panel apart. The old Kenwood had seen better days and the Alpine takes a really cool high speed cable from my Ipod to the stereo. The Ipod information, such as artist, song, etc displays on the Alpine stereo head, which is waaaay cool. The Ipod is tucked away in the center console and the cable is hidden from view. No one peeking in will ever know the Ipod is stashed away in the console.

Once again, thanks too everyone who helped me out with the 'No start" problem. Couldn't of done it without ya all pitching in to help.