Ok, so I've searched and searched. Here's what I've done so far

2004 RX8 auto w/ 135xxx mi.

*Replaced Battery
*Clean and check connections
*Check fuses with DVOM
*Check relays with 12v and DVOM test
*Tapped starter/solenoid with hammer

Everything checks out but when I try to start the car, it just clicks and the gauges go haywire. At this point I feel like I just need to replace the starter. Any thoughts?

 

The starter doesn't have enough current to turn the engine over. " it just clicks and the gauges go haywire" is completely classic of a poor electrical connection somewhere that is unable to sustain the high current flow needed for the starter. This is usually at the battery.

Just for the sake of completeness, go back to the battery and disconnect both connections. Clean both clamps inside and out. Clean the terminals. When you reconnect each clamp, do it slowly and ensure that the clamp is seated firmly on the terminal in a spot that it 'likes' before you tighten the clamp the whole way. I've seen tons of times that people just tighten the clamp and don't realize that they haven't made a good connection first, so either the clamp is sitting across ridges or the tightening nut is just tighting the clamp end with the clamp itself not tightening on the battery.

If that doesn't solve it, start digging for the other grounding points, because it's going to be one of them. Also remove and clean the starter's connections and resecure (only do this with the battery disconnected, those are live wires even with the engine off and key out)

 

Thanks for your input. I've had the cables on and off so many times, I'm sure one of the times I would have made a good connection. I will go and clean the connectors with baking soda and water and see if that helps. I'm pretty sure there is current flowing past the terminal clamp because I used my DVOM and found voltage after the fuse on the positive cable.

What do you mean to start digging for other grounding points? What is the best way to clean the starter connections?

 

There are numerous grounding points across the car. In this case, the next primary one to go after is the engine block ground, since the starter is returning voltage through the engine block and then through that ground.

There IS a weak ground somewhere, possibly even on a 'secure' connection that has corrosion between the two halves (been there, done that).

There will be voltage and current across the ground in question if you test it with a tester, but that isn't the concern here. For example, your dash cluster needs ~10.5-14.5v, and a tiny trickle of amperage. Your starter needs ~11-14.5v, but a flood of amperage. Your starter probably sees the tiny trickle normally, but the corroded connection is 'capping' the total amperage flow to far less than the starter needs.

The symptoms of this is a rapid clicking of the starter relay as it opens, can't flow, and shuts back off and gets the trigger voltage again, repeat. Usually this is also accompanied by flickering and/or spazzing gauge cluster since it's all digital and it's current flow is going haywire trying to feed the starter what it can't.

 

moved to the s1 section

Posted From RX8Club.com Android App

 

Finally figured it out, the positive battery terminal was bad. Even though it was allowing voltage to flow through it.