Anybody here have experience in automotive electrical issues?

Brent Dowell

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The ole pathfinder has some kind of weird electrical problem.

New battery, alternator seems to be generating a decent charging voltage around 14+ volts. It starts fine and runs good, but some of the accessories just don't work right. The dash voltmeter reads lower than my voltmeter on the battery. Put on the turn signals and the voltmeter bounces in time to the flashes. Turn on the headlights and the relays on the fuse box buzz and the whole electrical system goes crazy. Same with windows.

Going to run some more tests later to see if I can narrow things down.

Very frustrating in this heat to not be able to roll the windows down...
 
Thanks guys. Seems like the thing to check. I've got all the schematics, now if I can just find out where the fuse block gets it's ground, I'll give that a shot.

Funny thing is I've got a post on the nissan forums about this and not one suggestion. 1 hour here and look at all the help I got. And this forum isn't even about cars :eek: :thumb: :thumb:
 
Thanks guys. Seems like the thing to check. I've got all the schematics, now if I can just find out where the fuse block gets it's ground, I'll give that a shot.

Funny thing is I've got a post on the nissan forums about this and not one suggestion. 1 hour here and look at all the help I got. And this forum isn't even about cars :eek: :thumb: :thumb:

its like politicians brent they spout off about things they have no clue on like real jobs or work ethics:)
 
Check also the ground between engine and chassis. The battery to chassis (negative cable) may be corroded at the chassis, also.

Good luck. This kind of problem is often a bear to solve. (Sixteen years experience as an aircraft electrical technician - DAMHIKT)
 
since there is more than one problem / I would start at the battery and work mine way to the dash board--do your brake light/back-up light work--when I were having this problem [different car model] I bought a light socket plus bulb--I solder a needle to one of the socket wire/ and add a spade connection to the other wire---by pushing the needle into the insulator on the wire -you can find any breaks in the electric path
 
10 years owning an auto electric shop and I must concur with the people who have said to check your ground connections.

When people brought their vehicles in complaining about weird stuff we always started with grounds. There is no magic solution though, just have to check the grounds. Even if they look good, always check them to make sure you don't have corrosion or a loose or broken wire.

Karl
 
Well, followed the negative lead off the battery to where it had a bolt to the chassis. Pulled it, cleaned it, reconnected, etc...

I hook up the voltmeter to the positive pole on the batter and went around checking the chassis. Got good volt readings every where in the engine compartment and under the dash.

Am I not checking things in the right way?

If I were to run a separate ground, where should I connect it? The fuse block has only positive polarity on everything right? So there's nothing to connect to there, just need to find where the wiring harness goes to ground in the passenger compartment.

Very confusing.

Took it for a test drive and other than sweating like crazy, the truck runs smooth. I have to take it in for a smog check tomorrow, so I think it should make it the 25 miles to town and back.

After that I'm willing to take apart the whole dash if I have to in order to get this fixed...
 
Well if its items on the dash not working then run a wire from a known good ground to the dash where it is supposed to be grounded.


No there won't be a ground at the fuse block. What is usually supposed to happen is the frame and sheet metal are all supposed to act as one big ground wire. But then where all the items tie to ground there is a potential for failure.

Also most dashes have a instrument regulator or did in the past. It is hard to talk about these things in generalities anymore because in many vehicles there are multiple networks and separate computers running things via data rather than just B+ and Chassis ground.

But if most items that are failing are in your dash then you need to look at where the dash picks up ground or just run a known good ground to a point on the dash that is supposed to be at ground potential.


As an example of how it isn't as simple as it should be on my Chrysler products minivan the engine computer monitors the battery voltage and sends the feed back back to the alternator acting as the voltage regulator.. A dealer ship will tell you the only solution if you have a regulator failure is to replace and reprogram the Engine control computer at a cost of around 5-6 hundred dollars plus labor. However the alternator is the same as it has been for many model years and a 10 dollar regulator from an 80's model and a few feet of wire will fix you right up.

Garry
 
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Brent,
Just connect an insulated wire from the Negative on the battery to the ground connection on the cigerette lighter. Thats what I did.

But if most items that are failing are in your dash then you need to look at where the dash picks up ground or just run a known good ground to a point on the dash that is supposed to be at ground potential.

As an example of how it isn't as simple as it should be on my Chrysler products minivan the engine computer monitors the battery voltage and sends the feed back back to the alternator acting as the voltage regulator.. A dealer ship will tell you the only solution if you have a regulator failure is to replace and reprogram the Engine control computer at a cost of around 5-6 hundred dollars plus labor. However the alternator is the same as it has been for many model years and a 10 dollar regulator from an 80's model and a few feet of wire will fix you right up.

Interesting.

Ok, Going to run a wire from the battery to the Ground on the Cig Lighter. I think I can even do that tonight!

This is an 87 pathfinder and is 'relatively' simple. One of the reasons I want to keep it. The other is I want to put a desert camo paint job on it and use it as a desert beater for exploring around here... Still runs good, only 180k on it. I'm working on fixing it up just to have as a spare, but it still needs to be smogged once a year...

Smog opens at 7:30am tomorrow. I'll be on the road at 7:00...
 
+ a bunch on the ground, and I'd just run new grounds to a bunch of places. Get some decent heavy gauge wire, and some crimp on conector things, crimp them on, and then solder them.

You can buy "Grounding Kits" like this......

cables.jpg
..... but as you can see, you can most likely just make a set of these wires.

Get your handy impact driver and some good sized self drilling screws and go to town, go from the battery to the frame then from the frame to the engine block, you will have to find somewhere to bolt on the connector end, but that should not be hard, make sure the metal on engine block is clean, like sandpaper cleaned.

From the frame to the body, or chassis run a number of wires, it won't hurt anything, they are just grounds.

I like to use the self drilling screws because you get into 100% rust free metal and get a great connection. Once drilled, I put a dab of grease on the head of the self drilling screws and connector, just to ward off rust.

The voltmeter in your dash may just be bad, or the connections on the dash somewhere are bad, I have never trusted one of the dash mounts things anyways, they are often really cheap stuff and not very accurate. :dunno:

Bad grounds are the worst thing to try to chase down, I just put in new grounds, less work.
 
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