My car is a 1985 Camaro with a 383, HSR and ECM/harness out of a 1990 Camaro.

Because of the ECM/wiring harness swap, the original check engine light wasn't hooked up, though the harness I bought has a lead for it.

Recently, I removed the stock cluster & replaced it with a full gauge set (including bezel) from AutoMeter. Their check engine light is just an orange LED that you hook power to, then hook the lead from the ECM to the negative.

After hooking up the new gauges & light, I thought everything was fine. When you turn the key on, the orange LED glows very bright, then when you start the car, it goes off. Or, at least it did.

For one of the first times, I drove my car at night and I noticed that the orange light is on very faintly. It's so subtle that you can't tell in daylight, only if you drive in the dark. So when you turn the key on, it's nice and bright; when the key is off, the light is completely out and other times, its partly on - if I had to guess, I'd say about 10% brightness.

I datalogged my car recently, when I did, it wasn't showing any codes present. I plan on checking it again sometime soon just to verify, I'm wondering if this is normal or an indication something is wrong, either with the wiring, the ECM or maybe an engine problem? Or will this light just always be "sort of" on because it's a LED? The turn signals and brake warning light are also LED's and I've had no issues with them. Thanks.

 

It doesn't take much current to get a response out of a led, as compared to a light bulb. The output transistor or ic in the ecm may have a little leakage that goes unnoticed when used with the usual bulb.

Turn signals and brake are switched by physical switches, so no opportunity for current leakage.

 

OK, thanks for the info. Does this leakage hurt anything? As long as I verify that there are no codes present, can I just leave it or is it something I need to fix?

 

Why not contact Autometer and ask them?

just a suggestion, since it is their product which is having the issue.