Hi, I have an '04 8, yesterday I was driving and I was going about 60 mph when all of the sudden my car just shut off. I tried popping the clutch twice while still going to start it, and then tried turning the key and neither worked. I pulled over and after about 30 min of looking for the problem, I found that the Ignition Key 15 amp fuse was blown. I replaced it with another, tried to start the car, and nothing. Checked the fuse again... blown. I did this 2 more times with the same result. I replaced it with a 20 amp fuse so I could at least roll up my windows. I noticed that with the blown fuse, the power windows didn't work, but the interior lights worked. I know that this means that there is a short in the circuit somewhere, but does anyone know where I should look more specifically?

Background on the car: 2004 6-speed, 109,850 miles on the car, and about 74k on the engine. I don't know when or if the coils/plugs/cables were replaced, as I've only had the car for about 2.5K miles. I did just replace the transmission with a used one with low mileage, and the clutch and flywheel. Would the starter have anything to do with it possibly? Any help appreciated!

 

Bump. Having a similar issue

 

My problem ended up being transmission relays and some melted wiring

 

how did you find out it was the transmission relays, where are they located, how much do they cost?

 

Transmission relays?

 

I too have a 2004 Rx8 manual trans, while driving made a left turn and the car died! check fuse box and found ignition fuse (15a) blown. checked connection replaced battery. blows fuse when key is in on position..WTF!

 

Looking at the Schematic....there is a lot of stuff fed from that one fuse. Your choice as to which system to disconnect first. I'd go by easiest to access .. .you will need a lot of fuses!
From term. 101 on the most likely "on" section of ign. switch:
1 Ign. Relay (B/Y= colour of all these wires)
2 Keyless control Module &...
EC-AT Control
Illumination Light
Dimmer Mirror
Power Windows (w/o DRL)
3 Inst. Cluster &
tire Press. Monitor
Headlight Leveling
Daytime Running Light (DRL)
turn/Hazard Lights
Backup Lights

Good luck with your trouble-shooting. Let us know what you find
Good Luck

 

I have this problem as well, I start hunting using the wiring diagram and it's my Black wire with Yellow. I tested it at Keyless Control Mod by unplugging it and ground the wire and it seems to be the culprit. Is there a fuse for it so I don't have to go down the entire wire? Im not the best at reading wiring diagrams so any help would be appreciated.

 

I'm not sure about the keyless entry module, but when I had this issue it was an ignition coil harness wire that had rubbed through on the engine hanger hook and was shorting out. This with a BHR ignition kit. See if that's it?

​​​​​
​​​​​​
​​​​​

 

So what it ended up being was that I had a short in the Black wire with the yellow stripe. As I was going down the list I thought about the reverse lights and how I had just put the tranny back in. It ended up being that the tranny cable was pinched between the bell housing and engine. When I pulled it out, sure enough, the only wire that was damaged was a black wire with a yellow stripe. Everything is back to normal.

 

It’s always a worse pain when the foot we shoot is our own!

 

check the downstream 02 sensor pigtail on the right side of the tranny. I had a fuse under the hood that kept blowing and would kill my car cause the melted wiring was grounding itself on the trans, after I replaced my clutch. the downstream 02 is on the same circuit as one of either the fuel or ignition circuits. I cant remember exactly which one but I know that's a common problem that no one can seem to figure out

 

If it dies instantly then it’s hooked to spark/ignition. If it sputters and engine power drops off before it dies then fuel because the pressure accumulator and fuel filter will hold just enough pressure to run those few seconds longer.
I had a similar problem in a different brand vehicle.