Alternator light and SRS light turns on

SHADY21

MEMBER
2003 ACURA RSX
2.0L
4 CYL
2WD
MANUAL
240,000 MILES

Hello,

My Type-S has an issue where the alternator and SRS lights come on at high engine speeds, around 5,000 to 6,000 temporarily. The radio also turns off. Once the engine speed comes back down below that, the lights go off and the radio comes back on. I assume it's the alternator. Do the parts stores test the alternators at high enough speed to duplicate the issue? Thanks.

1 Reply

KASEKENNY

MECHANIC
18,907 POSTS

I suspect you are correct that it is the alternator, however it could also be the spark plugs/coils. Here is a guide on the test that we need to do. I depends on the shop that will test them but there are tests at max output/RPM.

https://www.2carpros.com/articles/how-to-check-a-car-alternator

Normally the alternator output is regulated and does not increase with RPM unless the demand also increases.

However, the dwell on the spark plugs will increase at higher RPM. I would start with what you are thinking which is getting the alternator tested and if that checks out ok then I would replace the plugs before I replace the alternator. The reason I would still think to replace it even if it tests ok depends on the type of test. If it is an on vehicle test with max load and RPM and it passes then that would be accurate.

https://www.2carpros.com/articles/how-to-replace-an-alternator

However, if it is an off vehicle test or not at max operation then it may still be the issue but I would go with plugs first, then coils, then the alternator.

This is a common issue on Hemi engines and there is no real test for this so it is just a matter of replacing them and retesting. Make sure you are not using any cheap plugs or those split fire/multi electrode plugs. Those are the worst for this issue.

Let us know if you have other questions. Thanks

Image (Click to make bigger)