Vacuum erratic when electric fans turn on

[forestb]

So I borrowed a friend multimeter and went to start up my truck tonight and it turned over once and then would not turn over. The starter motor would just make a clicking noise. I looked at my voltmeter and it was down around 12 V. I use the multimeter that I borrowed and check the battery and it also was around 12 V. So I jumpstarted my truck and it started. I then proceeded to use the borrowed multimeter to check my distributor. Sure enough it did the same erratic reading then I moved the negative probe to the ground strap and it held steady at 14 V. I waited for the fans to turn on and it then held steady at 13.3 V. I have no idea why the battery drained that quickly in 2 days. I have not had any problems with my battery draining for a few years. The readings I am getting from my the borrowed multimeter are the same as the second one so I think that I am okay using my second multimeter.

[forestb]

I wonder if the battery draining is causing by starting the truck over the last couple of days and not driving it and just letting it sit at idle not giving the alternator a chance to change the battery. Also I wonder if my fan is connected to my starter instead of to the fuse block. I saw on a different thread someone saying that there fan instructions said to connect it to the starter and people said that you should not do that.

[The Rocknrod]

Is there a fan relay or just a power switch?

[Getter-Done]

Originally Posted by forestb

I wonder if the battery draining is causing by starting the truck over the last couple of days and not driving it and just letting it sit at idle not giving the alternator a chance to change the battery. Also I wonder if my fan is connected to my starter instead of to the fuse block. I saw on a different thread someone saying that there fan instructions said to connect it to the starter and people said that you should not do that.

In post #50 you mentioned
(I did notice that when I reinstalled my battery that positive battery cable sparked a little when it touched the post.)

You have a short somewhere draining the battery down.

[forestb]

Are there any tricks to chasing that down?

[forestb]

Originally Posted by The Rocknrod

Is there a fan relay or just a power switch?

There’s a relay. I believe it is activated by the ground being connected by a thermostat in the intake manifold

[Getter-Done]

Originally Posted by forestb

Are there any tricks to chasing that down?

Yes
By process of elimination.
Disconnect one circuit at a time.
I would start with your electric fan circuit.
Then your Alternator.
Use caution and tape wires that you take loose so then do not touch anything and ground out against anything.
You can disconnect each component.
Then check for the (arc) at your battery.

[forestb]

Good idea. Also I have a battery shut off switch that I turn off when not using the truck so that might help me illuminate some components. I have it for security reasons.

[forestb]

Is the starter supposed to be grounded somehow? Ir is it grounded because it is bolted to the engine block? I have a mini starter.

[67 Burb]

Originally Posted by forestb

Can you recommend a specific DVM?

Forest, for general voltage troubleshooting on your vehicle, that multimeter should do just fine.

[67 Burb]

Originally Posted by forestb

Is the starter supposed to be grounded somehow? Ir is it grounded because it is bolted to the engine block? I have a mini starter.

Starter is grounded to the engine block.

[forestb]

Originally Posted by 67 Burb

Starter is grounded to the engine block.

Is it grounded through the bolts or do I need to run a wire or a ground strap? What should I attach the ground to on the starter motor?

[forestb]

There is a seen in Better call Saul, where his brother tears all the wiring out of his house and yet he still cannot get the meter on the outside of his house to stop turning. That is how I felt today. I disconnected nearly everything I could think of and still it sparked when I touched the positive cable to the battery. I disconnected the:

Radio
Alternator
Fans
Distributor
Removed the power window fuse
Removed the turn signal fuse
Ac
Head lights
Unplugged the ignition
Choke
Cigarette lighter
Windshield wiper
Steering column
Break light switch
Neutral safety switch
Voltmeter
Oil pressure sender
Removed the dome light fuse
Removed the giant Painless Performance fuse.

After all of that it still sparked at the positive cable. The only things I didn’t try was the starter which I don’t know how I could do that without removing the positive battery cable. I also could not figure out a way to disconnect the fuel sending unit.

When I switched off my battery kill switch I still seemed to get a spark. My only thought is that I need to ground the switch. Ground the starter and ground the radiator support to the frame. I took a photo of the starter plug.

[forestb]

Here’s the photos

[forestb]

Every so often I get a shock from the horn when I press on it and the horn fuse goes out from time to time.

[The Rocknrod]

Originally Posted by forestb

Every so often I get a shock from the horn when I press on it and the horn fuse goes out from time to time.

That would be a short (fuse goes out) Need to ground your column also.

[forestb]

How should I ground my column? Is there a specific bolt that you recommend?

[forestb]

This is the battery cut off switch that I have. https://www.summitracing.com/parts/tay-1032

I am trying to figure out the best way to ground it. Would it work if I soldered a ground wire to the mettle housing?

[forestb]

Did everyone give up on me?

[Getter-Done]

Originally Posted by forestb

This is the battery cut off switch that I have. https://www.summitracing.com/parts/tay-1032

I am trying to figure out the best way to ground it. Would it work if I soldered a ground wire to the mettle housing?

This type of switch does not require a ground.

[forestb]

Originally Posted by Getter-Done

This type of switch does not require a ground.

Yay thanks. One less thing on my list of things to ground.

[pjmoreland]

Originally Posted by forestb

How should I ground my column? Is there a specific bolt that you recommend?

Do you have a grounding strap in your steering column rag joint, as shown in this post?

http://67-72chevytrucks.com/vboard/s...10&postcount=3

[forestb]

Originally Posted by pjmoreland

Do you have a grounding strap in your steering column rag joint, as shown in this post?

http://67-72chevytrucks.com/vboard/s...10&postcount=3

From what I can remember I do not have anything like that but I will take a look. But I am not sure that will work with my setup. I have a knuckle joint and a sleeve that the steering column slides into. Does that ground the column to the steering box.

[pjmoreland]

Originally Posted by forestb

From what I can remember I do not have anything like that but I will take a look. But I am not sure that will work with my setup. I have a knuckle joint and a sleeve that the steering column slides into. Does that ground the column to the steering box.

Yes

[forestb]

That definitely seems like the kind of part that an good intentioned back yard mechanic friend might leave off after not reading the instructions.

I will try something like this over the weekend. https://www.corvetteforum.com/forums...rag-joint.html