ECM blowing fuse

DKCOOPER

MEMBER
1981 CHEVROLET CAMARO
5.0L
V8
RWD
AUTOMATIC
160,000 MILES

Every time I try to get the codes off of my ECM there is a rapid clicking coming from the relays in the front left of the engine compartment by the MAP sensor and then the gauge fuse blows.

Car starts but not easily and does not idle without help.

I have cleaned all connections and checked the engine ground.

Any help is greatly appreciated.

3 Replies

STEVE W.

MECHANIC
13,443 POSTS

Which connector are you trying to use and how are you connecting to it? 1981 could have a 5 pin or the 12 pin.

If it is the 5 pin for the CCC system you jumper the last 2 pins on the right.
Just do not expect much as that first generation CCC is very primitive.

Your description sounds like a carburetor rebuild is needed. Especially if you are running modern gas. The alcohol damages the rubber seals and parts in those carburetors.

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Monday, September 18th, 2017 AT 4:05 AM

DKCOOPER

MEMBER
2 POSTS

Sorry for the delay in responding, but I did not get an email notification.
It has the 5 pin connector. I am connecting the last two pins on the right as you have described. I was just hoping to get whatever codes I could but it keeps blowing the fuse.
I agree a carburetor rebuild might be in order but that should not cause the clicking and loan fuse. Correct?
Thanks!

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Monday, September 18th, 2017 AT 7:49 PM

STEVE W.

MECHANIC
13,443 POSTS

It should not. All the jumper does is pull pin 5 on the PCM itself to ground to activate the diagnostics.

Take a look at the wires coming out of the back of the connector. Pin 5 should go to ground and Pin 4 should be a White wire with a black stripe. It is possible yours is wired backwards or the connector is upside down?

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Monday, September 18th, 2017 AT 9:24 PM