Fail safe mode after cooling upgrade

[DBcooper]

I just finished converting my 2005 mustang GT cooling system over to the 2007-2009 system. I swapped the coolant crossover and alternator mounting bracket over to the newer style. I added a new motorcraft 192 degree thermostat, Mishimoto radiator and hoses, Meziere electric water pump, and Ford performance cooling fan.

I buttoned everything up tonight. Filled it with coolant and started it up. The car runs like absolute crap. Throwing codes p0102 p0480 p0481 p2106 p0581 p2105. it keeps going into fail safe mode wanting to die. It’s also got a bad miss. I never saw the fan come on once. Any ideas? I thought the fan was plug and play. I didn’t update my tune. Do I need to? Thanks in advance. I’m completely lost. Any help would be appreciated.

 

[DBcooper]

I should add that the car was getting hot before the swap. I’m going to check the relays and fuses as well. Any other help is appreciated

 

[Dino Dino Bambino]

Did you disconnect the battery before you started all that work?

 

[DBcooper]

Did you disconnect the battery before you started all that work?

Yeah I did. I had it connected for a moment or 2 when finding a fuse that was hot when the key was on for the water pump. But that’s it.

 

[Dino Dino Bambino]

That's good. At least you wouldn't have accidentally fried the ECU, especially when you were moving the alternator around. You definitely don't need to update the tune, but you might want to check all the wiring connectors in case you missed one altogether or didn't connect it properly.
I'd wager the solution is something very simple like that.

 

[JC SSP]

Where did you wire the Meziere electric water pump to?

 

[DBcooper]

Where did you wire the Meziere electric water pump to?

I ran power for the relay to the back of the alternator. And for the switched power I used an add a circuit - it looks like it’s on the same circuit as the fuse for the radiator fan. It’s only hot when the key is on

 

[JC SSP]

Ok I am not an electrical expert, much more mechanically inclined, but did the WP instructions specifically state to connect directly to the alternator?

Everything else that you installed is non-electrical... so its either WP connection or you left a connector unplugged/not fully seated or something electrical got damaged or has corrosion?

 

[DBcooper]

Ok I am not an electrical expert, much more mechanically inclined, but did the WP instructions specifically state to connect directly to the alternator?

Everything else that you installed is non-electrical... so its either WP connection or you left a connector unplugged/not fully seated or something electrical got damaged or has corrosion?

I thought it was odd to run the power directly to the alternator, but that is what the water pump directions stated to do. I have double and triple checked all connections.

My car was getting hot before the swap, but it wasn’t going into fail safe mode. I thought it was due to the fan not turning on. But I replaced that and the resistor that tends to fail. I don’t see any corrosion around the relays in the fuse box. All the fuses look good.

I may remove the wiring harness for the water pump tonight and see if anything improves.

 

[07 Boss]

I never hooked my water pump up to the alternator. I think I ran power from the battery and the switched power from the cruise control fuse (only on engine running). I never think I looked at the instructions as I have wired up many a pump. Though I'm not sure what difference it makes but I would not think the battery or back of the alternator wouldn't really matter. I would think it was somewhere in your wiring as those codes range from MAF to cooling to cruise control. I know when there are certain low voltage or charging issues you can get some weird codes but I've never seen this combo pop up.

 

[JEWC_Motorsports]

Never run anything off the alternator. You are causing the computer to see the wrong values from the alternator.

 

[DBcooper]

I never had time to work on the car tonight. But I was able to remove the negative battery terminal for an hour to reset everything. Then I removed the add a circuit from the fuse box and put the original fuse back in its place. Started the car up without the water pump and everything ran normal. No codes. Huge relief.

I obviously have something wired incorrectly on the water pump. It’s a head scratcher for me because I know the pump was working the way I had it wired. I could hear it running and I could see coolant circulating in the overflow tank

 

[JEWC_Motorsports]

https://mustangforums.com/forum/200...y-electric-water-pump-install-w-pictures.html


This will walk you thru it

 

[JC SSP]

That’s why the is forum is best!

 

[DBcooper]

https://mustangforums.com/forum/200...y-electric-water-pump-install-w-pictures.html


This will walk you thru it

Thank you

 

[Dino Dino Bambino]

https://www.meziere.com/Products/Co...Plugs/WN-Fittings/WP346-INSTALL-REV-A-65.aspx

https://www.onallcylinders.com/2022...ter-pump-upgrade-2007-10-cooling-system-swap/

 

[DBcooper]

I am finally getting around to updating this thread. I had intended on removing the power wire from the back of the alternator and running it to the 12 v stud on the under hood fuse box. Before going to the trouble to do this, I moved the add a circuit for the switched power for the relay from #40 to #42 just for the hell of it. I’m not sure why this fixed the problem, but it did. Both circuits are hot when the key is on.

Anyways. Very easy fix. Driving around town with the AC on in 90 degree weather keeps the temp on my SCT tuner between 196 and 208. I appreciate everybody’s help. Thank you! If anybody knows why circuit 40 doesn’t work, please fill me in. It’s got me scratching my head