2007 GTI won't turn over

[new2seadoo2022]

Hi, my family recently acquired two 2007 SeaDoo GTI SE 4-tec jet skis (Both skis have less than 200 hours on them), and we've been having some trouble getting them running. One of the jet skis starts and runs fine, but the other one is having some problems. When we put the key on the post the dash comes on, the ski beeps twice, and then begins the series of four beeps indicating that its ready to start. When we hit the start button we can hear the fuel pump come on, but the starting solenoid does not click, and the starter remains quiet. We have never owned jet skis before and we have run out of things to test, I'm hoping someone has had this same issue before or knows where we should look next. Here's what we've tried:
1. The ski has a brand-new battery in it (It has been tested and is working fine)
2. We took the starting solenoid out of the running ski and tested it in the one that won't run, it didn't change anything. Vice Versa, we put the solenoid out of the bad ski in the good ski, and it started with no issues.
3. All of the fuses and relays are in good shape. We even swapped over fuses and relays from the running ski to the bad one, it made no difference.
4. We've cleaned the battery cables and the terminals on the starting solenoid
5. We've tested the start/stop switch and its operating like its supposed to
6. As a last resort we used a jumper wire to jump across the terminals on the starting solenoid, and when we did the engine immediately started to turn over with zero issues.

 

[ski-d00]

Switch the ECU and lanyard from the running ski into the non-running and see if it cranks. It might not start since the ECU isn't married to your cluster but should crank which is a simple test to check the ECU.

 

[new2seadoo2022]

Switch the ECU and lanyard from the running ski into the non-running and see if it cranks. It might not start since the ECU isn't married to your cluster but should crank which is a simple test to check the ECU.

We actually were able to figure out what was going on with it! As a last resort we ran our own ground wire from the negative terminal on the battery and clamped it down to the engine block. When we did that, the ski started fine. Both of these skis spent their lives in the saltwater, and as near as we can tell the corrosion did a number on the engine bay and caused grounding issues with the starter.

To compound the issue further we discovered through trial and error that one of the lanyards will start both skis, while the other will only start one ski, but turn on the dash on both. When we got them, I did some research and discovered that one key can be coded to be used with multiple jet skis, so we went into it assuming that was the case. It was not.

 

[ski-d00]

Any key will turn on the dash but only programmed to the ECU ones will start it. You can program up to 8 keys to a ski. You can get the key that only starts one to start them both by getting it added to the ECU by any seadoo dealer.

 

[new2seadoo2022]

Good to know, we'll get that done so we don't have to try and keep track of which key is which