No power to scan tool to pull codes

Hello everyone, I have a 1999 xj the check engine light came on and stays on. There are no problems with it running. I have tried two scan tools to pull codes. They wont power on. I did check power at the connection. There was power there ,but I am not sure which terminals do what. I guess I need to get a wiring diagram. Where can you get a wiring diagram? Anyone else have this problem?

there's only one spot the ODBII scan tool plugs into....? you can always take it to AutoZone and they'll read the code for you for free....

Hello JNickel101 I took it to autozone the scan tool they had did the same thing mine did . No power ,I checked some of the connections at the ECM. They all looked good. Iam thinking maybe a wire is broke somewhere.

Could be, OBD2 should be nifty.

OBD1 can be troublesome. For some reason I can't get a reader to connect to my OBD1 because it says "no signal" or whatever. Tried two different scanners and two different hookups, one where we jumped the terminals and the other where the actual same OBD1 interface cable/plug was used.

I just used my dad's new obd2 scanner powered by a 9v battery. It might work for you if the only lead that is dead is the one it needs to power up. The scanner was dead on with its diagnosis of the CEL that I had fixed the day before: "high MAP voltage input" due to me breaking a lead on the variable resistor on my adjustable MAP when I hit a nice pothole on a detour and immediately after the engine was stumbling due to the injectors flooding out the engine with the 12v input.

Thanks to everyone for your input. Iam going look around this weekend for one of those self powered scan tools . I would like to get some wiring diagrams ,the ones in my service manuel dont cover this.