Voltage drop and trouble starting

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escociabhoy

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I've been using a radar detector with a voltage readout for the last few years, I've always had a voltage +/- 14.5, a few weeks ago I noticed the voltage was dropping and climbing rapidly from 12.2 - 14.5 on a long drive, I then had trouble starting the car for the next few days. I read some of the posts on this site and a few others and decided it was probably the alternator on it's way out after 63,000 miles. I replaced the alternator with a refurbished OEM Denso unit that I got online, once replaced the problem persisted, I took it to autozone and had them replace the battery which was still under warranty, the problems persist. My voltage starts off around 14.2 and slowly drops to 13.5 after an hour or so of driving, sometimes my starter tries to stay on after the engine has started, sometimes it stutters a few times before starting. I'm currently working out in West Texas and the nearest LR dealership or indie is 350 miles away and the local mechanics seem perplexed when I explain the issue to them.

The only thing that I think could also be related was a reduced engine performance message that appeared a week before the voltage/starter issues, the code showed it to be a faulty ECT sensor, I bought a new sensor however the fault has since disappeared and not come back so I haven't replaced the sensor yet.

Could it be a 2nd faulty alternator? Any ideas?
 

tlt

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I think bbyer got a bad refurbished alternator at some point. 350 miles away, Austin LR Dealer by chance? Check your negative battery cable for corrosion at the terminal, and at the body bolt, just to the left of the battery.

Clean it, make sure it is getting good contact. The voltage regulator is built into the Alternator.

Carefully inspect the starter wires, and other wires for rubs, it is possible your getting some short somewhere.
 

escociabhoy

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No corrosion on the battery connections and the body mount seems to be ok. After reading about the starter motor in the workshop manual it seems hard to get to and I don't have any car jacks with me to get under the vehicle and get a good look at the starter so I guess I'll have to wait until I'm back in Houston to get it looked at.

I spoke to the company I bought the alternator from, they've offered to replace it free of charge so I might try doing that first to see if the alternator is the problem.
 

tlt

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I'd opt to swap the Alternator. It seems logical, seeing as it was recently changed. Is it a Denso?

I did some searching around, and found (and have heard before) "When I changed my alternator it was purchased from ECP and overcharged and brought up EPB warning light. Returned alternator to ECP and got another unit and again same fault. In the end purchased a Denso alternator and now all is ok. It could be an issue with the alternator that has been installed and causing faults. What is the voltage the new alternator produces on start up"
 

escociabhoy

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Yes it's a Denso, I called the customer service line of the store I bought it from and they told me that they have only had one returned because it was faulty in all the time they've been refurbishing them, but they offered to replace it free of charge so I'm going to go ahead and do that first before I do anything else.
 

tlt

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Keep up posted.. Where did you order it, cost, etc?
 

bbyer

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Yes, faulty alternator for me.

Yes, the first WAI, (Wilson), rebuilt alternator I had put in by the local leading alternator shop here was defective - showed up within a week.

t made enough electricity to run all loads but the voltage output was low, about 13.3 volts, a default number it seems.

I figure it was the regulator within that was defective as the free replacement later displayed at up to 14.8 volts but would run closer to 13.8 to 14.1 under normal conditions.

When you get the replacement alternator, count the grooves in the pulley - sometimes the wrong pulley gets installed so you have to swap pulleys with the removed unit.
 

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