Electrical help

[426rider]

I think I have a short somewhere but don't know what I am doing. I looked for obvious signs, burnt, bare wires, and corrosion but didn't see anything.

I have an 85 toyota 4 runner with a 92 chev 4.3 tbi. (not wired by me). And a few things that I have wired, offroad lights, cb, tail lights etc.(one of my jobs is most likely the source somewhere)

I had an alternator go out on me and I drove back to camp on just the battery power. I replaced the alternator (shucks warantee replacement) and had some intermittent issues starting since. Now basically every start I have to jump it. The original battery seems to hold a charge but thought it suspect anyway, I tried the battery out of my car, started once then would not start again. Put the battery back in my car and it starts fine every day. When I run the 4 runner for hours the in dash voltmeter reads that it is charging and a multimeter at the battery and alternator reads that it is charging in the 14v range. The battery is around the 12.9v area and it will not start without a jump or start box.

So basically where do I start and what to look for?

 

[crash2]

Does the starter click or anything?

Start by disconnecting the starter trigger wire(small wire at the starter) and take a volt meter and have somebody turn to start it and see what the voltage is. Thats how you want to start and go from there.

 

[426rider]

Yes, starter will click, and in cab light dim quite a bit. I will check that and report back.

 

[crash2]

Once you verify 12v to the trigger wire do the same at the main power wire at the starter. Then redo it again at the battery terminals and compare the voltage. If its different then you have a connection issue.

 

[426rider]

Ok well, I didn't check the voltage at the trigger wire,( I was out there when you sent the last reply) just at the batt when someone turned the key. Battery went from 12.9 to 12.4. Hooked up the battery and the trigger wire and the 4 runner started, like 6 times in a row. The last time it started the positive terminal sparked. So I pulled the positive wire off the battery scrubbed it clean, even though it wasn't that dirty. Put the positive wire back on and it won't start, just a little click and an electrical drain sound. Voltage at the battery dropped to like 6.0 when trying to start and it would just click.

So I am thinking that the trigger wire may have a bad connection somewhere? or may be grounding out?

Could the connection be bad in the starter?

 

[crash2]

So the voltage at the battery dropped to 6 volts?

If thats the case you have
1)bad battery(sounds like you ruled that out)

2)large voltage drop due to a poor connection either at the battery or the starter or

3)bad starter

 

[426rider]

Dropped to 6v when trying to start, then back to 12.8 or so when not trying to start.

I'm starting to think it may be in the starter/ solenoid

 

[messix]

could be shorted armature on the starter. if it lands on the part it will draw short, if on other parts work ok.

 

[crash2]

could be shorted armature on the starter. if it lands on the part it will draw short, if on other parts work ok.

I have never seen a shorted soleniod on the pass-thru power portion of it just the action side. But ya as troy said if anything it would be on the armature side pulling so many amps be it a short in the armature or at the brush assembly.

 

[junkyard jim]

Or a bad ground at the block. Electrical needs both a power path and return ground path to function. Rubber motor mounts are a POOR conductor!

 

[GaryTJ]

Take a voltmeter and connect one wire to the positive side of the battery (not cable) and the other to the positive terminal at the starter (not the wire) and get it to act up. Read the voltage.

Do the same from the engine block to the negative side of the battery (not the cable)

If you get more than a 1/2 volt reading on the voltmeter you have a cable issue. if less, replace the starter. It could be that have both issues too.

 

[hookandpull]

Some things to try....

- Verify how many ohms (resistance, symbol looks like an upside down u) your negative battery cable is running to ground when disconnected. You do this by connecting one meter lead to a known good ground and the other to the cable(off of the battery)

- Have the battery tested under a load (that means removing it from the vehicle and putting it on a load tester)...

Do this first and get back to me. I am an Electrical Engineer by trade so whatever is going on is probably really simple. But annoying. The guys on here are all giving you good advice, but start with your grounds, that can always wreak havoc

 

[Travis1]

Had my Jeep do something similar. Turn the key, hear a clank, and two yellow tops go dead - DEAD, no lights, nothing. The CB which is on it's own fuse block hard wired to the battery went dead too. After a bit, it would come back on, on it's own.

Swapped batteries, same deal.

It was the starter.

 

[GaryTJ]

Some things to try....

- Verify how many ohms (resistance, symbol looks like an upside down u) your negative battery cable is running to ground when disconnected. You do this by connecting one meter lead to a known good ground and the other to the cable(off of the battery)

- Have the battery tested under a load (that means removing it from the vehicle and putting it on a load tester)...

Do this first and get back to me. I am an Electrical Engineer by trade so whatever is going on is probably really simple. But annoying. The guys on here are all giving you good advice, but start with your grounds, that can always wreak havoc

I agree with you except for the Ohm's test. The voltage drop test is a much better test. (as I described)

You can take a battery cable and cut all the strands except one and it will pass the Ohms test, but it won't start a vehicle.

 

[hookandpull]

I agree with you except for the Ohm's test. The voltage drop test is a much better test. (as I described)

You can take a battery cable and cut all the strands except one and it will pass the Ohms test, but it won't start a vehicle.

True...