86 corvette

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Oct 16, 2015 | 03:30 PM

Crackerjack01

Thread Starter

3rd Gear

Joined: Oct 2015

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86 corvette

I have a 86 corvette, and trying to figure out why I don't get power to my ECM. I plug in OBD II with an adapter OBD 1 and I do not get any read out. Mt OBD goes out. I am thinking there is no power to ECM or I have a bad ground wire. Dash light work but no gage readings. Any Ideas?

Oct 16, 2015 | 03:38 PM

crowz

Melting Slicks

Joined: Jun 1999

Posts: 2,931

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From: Ashland Alabama

Sounds like a blown fuse to me. Did you check your fuses?

Oct 16, 2015 | 04:36 PM

John A. Marker

Le Mans Master

Joined: Mar 2004

Posts: 5,107

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From: Dublin CA

It may be your reader or adapter.

Use this simple method with a cut off paperclip. Insert clip into A & B then turn on key to the ON position...don't start the car...count the flashes.... Crude but it works....

http://www.corvettephotographs.com/c4vettes/codes.htm

Oct 16, 2015 | 11:26 PM

Cliff Harris

Race Director

Joined: Apr 2002

Posts: 10,036

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From: Anaheim CA

The ECM lights the SES light. If that works then the ECM is getting power. The same power source (fusible link) powers the fuel pump.

Oct 17, 2015 | 01:09 AM

crowz

Melting Slicks

Joined: Jun 1999

Posts: 2,931

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From: Ashland Alabama

Quote:

Originally Posted by Crackerjack01

Does your adapter plug in some where to get power to run your scanner? Obd 1 doesn't power scan tools. All of my obd 1 equipment plugs into the cig lighter or such to run. Obd2 is powered by the port itself normally.

There are fuses for the lcd cluster. Check those too. When you say it "lights up" do you mean from the key or the illumination from the headlight ****?

Does the car run? If so the ecm has power. If not and you have all these issue then it may not have power.

Connector C16 and B1 on the ecm itself should have 12volts present at all times. If they don't then the fuseable link is bad going to the battery or you have a connection issue going to the battery.

Oct 17, 2015 | 01:12 AM

crowz

Melting Slicks

Joined: Jun 1999

Posts: 2,931

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From: Ashland Alabama

Oh and connector A6 on the ecm is the one that turns it own aka senses ignition switched power. If power isn't present on that wire when the keys turned on the ecm wont come on and wont turn on the service engine soon light.