2004 Buick Regal 3.8L
 

Hello all.

I have a no crank/no start issue.

I checked all fuses and tested all relays in the engine compartment and on the passenger side of dash.
Battery is two months old and charged properly.
I also found four relays behind the glove box that are not on any diagram. I'll get back to those later.

I attached a remote start button to the starter and started the car. Sounded like a coffee grinder then stalled within 10 seconds.
I changed starter, still won't crank.
When attempting to crank, the fuel gauge drops from 3/4 full to empty. It rises back to 3/4 when the key is returned to the run position.

Codes present are U1000, U1016 and U1064.

One of the relays behind the glove box houses a purple wire that was continuity tested to the starter with .6 ohms.
In this relay, I have constant 12VDC on pin 30. When the ignition is turned on I have 12VDC at pins 85 & 86, but I have NO voltage at pin 87, which is the purple wire. I swapped out another relay for shits & giggles with no improvement.
Does anyone know what the four relays behind the glove box control?

I'm trying to work my way back to perhaps the ignition or neutral safety switch, but these codes have me thinking that's not the correct path.

I'm working with a Bosch scan tool and a digital multi meter. I don't have an oscilloscope or break out box.

Any help would be greatly appreciated.

Thanks

Lou

Sounds like the starter stayed engaged. How's the ring on the flex plate?

I suggest you check for power being delivered to the appropriate relay when you turn the ignition switch to <start>. If this is successful, next look for the high-power side of the relay to deliver power to the starter solenoid when you turn the ignition switch to <start>.

The ring on the flex plate is good.

Need to do some work with your DVOM.

Hello again.

The codes presented because I inadvertently had the key on and removed a fuse. I cleared the codes and they have not come back.

I have worked my way back to the ignition switch. With the covers off, I noticed two white 20ga wires on top of the ignition cylinder in the plastic bezel that surrounds the opening for key insertion. One of the wires is broken close to the bezel. Of course. What do these control as I can't find them on the schematic I have.

The ignition switch has has power to yellow on crank only, constant power on red and pink and power on all others when switch is in the run position.

Thanks in advance for you help.

Lou

Did you check the starter relay like Cathedral Club said? It's easy enough to swap relays. If you have someone turn the key to crank you should hear a clicking at the relay.

Yes indeed.

if it the white wires I am thinking about that would be for the RFID reader to read chip in the key is the security light on

it will not start with that wire broken