I have a 2008 Mercury Mariner, that I bought 2 years ago. I bought it at a local insurance auction. Repaired the damage it had to the left front. When time came to start it, it wouldn't start. I took it to a local dealer and it was diagnose with a bad transmission, they said the generator that turns the engine was burnt. I replaced the transmission with a used one. The truck still won't start. I took it to a different dealer and they diagnose a bad throttle body as the cause. I replaced it with a new one and it still didn't start. All the electrical stuff works fine on the inside. The rear battery is barely showing any power on the dash. Is their anyway to charged it or check the voltage on the battery? Does it make any difference if the a/c system is not charged? It only has 6,500 miles on it and been sitting for 2 years. Any suggestion would be appreciated.

thanks

 

The High Voltage battery turns over the engine; the low 12 volt front battery powers up the electronics so that the rear battery can work. From the 2008 FEH owner's manual:

JUMP STARTING THE HIGH VOLTAGE BATTERY
Your vehicle has two separate jump starting procedures; the following procedure is for the cargo area high voltage battery only. Refer to the Jump starting your vehicle (Low voltage [underhood] battery only) section in this chapter for information on jump starting the low voltage

Do not attempt to push-start your vehicle. This vehicle does not have push-start capability. If you attempt to start your vehicle and the engine cranks but does not start, the high voltage battery may need to be jump started

The Service Soon (yellow wrench) light in the instrument cluster may also be illuminated and the message center may display a message. To jump start the high voltage battery, turn the ignition to OFF, open the access panel in the driver side foot well and press the jump start button momentarily. After pressing the button, you should wait eight minutes before attempting to start the engine, otherwise the high voltage battery may not receive sufficient charge to start the engine. The high voltage battery will use voltage from the low voltage (underhood) battery to charge itself. When the button is pressed, the indicator light on the button will illuminate. After eight minutes has passed, the indicator light will flash rapidly for two minutes. Turn the ignition to RUN. You may now attempt to start the engine. If you attempt to start the engine before the eight minutes passes, the jump starting procedure will stop and will have to be restarted if the engine does not start.

 

I tried this procedure already. It didn't work.

 

Hi Al

This is a strange situation your in because not knowing a lot of facts regarding before and after the accident puts me at a loss to help you.

Was the MMH ever started or drivable after the accident and do you have any details of what the accident involved?

I'm assuming this is a salvaged MMH but was it salvaged due just to the body damage only?

Was the 12V battery damaged in the accident and could that battery have been shorted out? The reason I ask is the PCM needs the 12V battery to shutdown the relays to stop the HV DC to LV DC converter from draining the HV battery. Also, if the key was left in the ON position for a long time that could have drained the HV battery.

I'm also assuming you reset the automatic fuel and electric shutoffs switches from the accident.

The A/C must have a full charge for the HV battery AUX A/C system to regulate the battery temperature but I see no reason it has to be charged to start the engine. Here again one of the fail safe systems would stop overheating by shutting down the use of the motor/generators from charging or discharging the HV battery.

The relays in the battery junction box could also have been shorted out and you may want to have them checked. They caused my FEH not to start and it cost me ~$1200 to find that problem. Here is some photos of those relays: http://www.cleanmpg.com/photos/showg...ge/2/ppuser/36 You may want to replace those relays and try the jump start procedure again.

GaryG

There are many fail safe systems to prevent a burned out motor/generator

 

The accident consisted of replacing the left fender, hood, bumper, left headlight. The truck had no frame damage or deployed airbags. Theirs was no damage to the rear battery. I will check those two relays in the junction box.