Hi,
My car had a pin hole in the upper radiator hose that leaked coolant onto my alternator. I noticed the leak when my car stopped charging. I am 100% sure that the leak was there for no more than 3-4 days and leaked about 1/2 quart of coolant. I checked the fuse and the belt tension which all checked out good. I pulled the alternator and three auto parts stores said that the alternator checked out fine.

I plan on checking the wiring to the alternator tomorrow or Friday. Any suggestions on what I should be looking for? I don't believe in coincidences and believe the leak had something to do with this problem.

I'm hoping that for the few hours between the time the alternator was takng out of the car and brought to the auto parts stores to be tested it had dried out. For the record, the car sat in my driveway for two days before I pulled the alternator. Of course, just before I pulled the alternator I started the car and it was not charging.

Thanks,
Jomo

 

There is a fuse # 10 / 5 amp ( tan ) right engine bay fuse box

This fuse is the power to make power ( excitation ) that is shared by other items on the car

 

Was your initial fuse check the same fuse # 10

The right engine bay fuse box relay ( ignition positive relay ) is closing for the ECU powering ( fuse # 12 / 10 amp right engine bay fuse box in the pic above ) or no engine run

 

Y

 

Yes, I did check the fuse that you mentioned.

 

The other wire to the voltage regulator ( inside the alternator ) is the gauge indication

This is the round 2 wire connector on the alternator

There are 2 or 3 fuses in the left heelboard fuse box for the instrument cluster

Did you check the voltage on the B + post of the alternator before changing it

An easier check point is the large terminal post on the inside the engine compartment right front wheel well near the rear firewall

The alternator B + heavy battery cable ties into the starter solenoid on the way to the right wheel well terminal post and this rear section would normally be referred to as the starter cable

The valve cover is not a good ground point

You should see 13.5 to 14.5 volts which is above the fully charged battery of 12.75

 

How are your checks doing , but it is the holiday

 

G'day Jomo,

After you’ve done all the checking suggested by Parker you have to ensure that the lead from the alternator all the way to the battery ground point, and all the various connections on it are clean and secure. They tend to loosen over time and you will not get full charging voltage to your battery and you could also have an intermittent starting problem.

The connections are , alternator, junction on starter motor, junction on the firewall/footwell, under the rear seat on the RHS there is a fuse box with several connections, the positive battery connector also has a fuse box with two fuses within, the negative battery terminal and the ground point on the boot wall. All these need to be clean and tight.

Cheers,
Jeff.

 

you smoked your voltage regulator

 

I put back the alternator and it is working fine. The only thing I did was spay electronic cleaner on the plug going to the alternator as it looked dirty to me.
I can only assume that the alternator didn't dry out enough after sitting two days in my car in the driveway, but needed an extra few hours. At that point it checked out fine at a few auto parts store.

 

Be careful to not tighten the positive battery post too tight as this cracks the nut in half underneath the terminal bolt

fortunately the instrument cluster gauge is very accurate compared to a hand held meter , just the hash markings desirning in the heat of battle

 

On ,my 1995 X-300 the problem was the right front cowl/firewall terminal for the main power supply from the battery to the engine compartment. The rubber insulator had corroded and at night I could see sparking from the terminal to the firewall,