I'm having a problem with the starter not engaging. If I hold the key in the start position, the starter briefly engages then nothing then it briefly engages then nothing. This will go on as long as I hold the key in the start position. When checking the voltage to the solenoid I don't get a 12 v reading, but I'm sure that is because the dvm can't read the voltage reading fast enough. The starter engages just long enough to bump the engine. I think it's a problem with one of the control modules, but I don't have access to wiring diagrams or troubleshooting guide. Any suggestions?