Voltage issues

[Matt69olds]

Carefully inspect the battery cables. They can be corroded inside the insulation where it’s hard to see.

If the battery load tests hood, before spending another dime do a simple voltage drop test.

Get a voltmeter, put the positive probe of the meter on the positive post of the battery. Put the NEGATIVE probe of the meter on the POSITIVE cable end AT THE STARTER. Crank the engine while looking at the meter. Whatever the meter reads is the voltage lost in the cable. If it’s more than a couple tenths of a volt, either the cable is undersized, or you have a bad connection somewhere.

You can do the same thing on the negative cable, just reverse the connections.

Another possibility: inspect the advance weights in the distributor. If they are corroded, they can stick in the advanced position. Remove the cap, twist the rotor, the rotor should snap back to it’s original position. If not, inspect, clean and lube the advance weights. If they are sticky, reset the timing once they are fixed.

 

[iamtherealJayy]

For testing the negative is the probe going to same spot on starter or? I understand testing positive but slight confusion on testing negative

 

[wlwarnke]

Testing the negative is the exact same as testing the positive. Polarity doesn’t matter. 0vdc is perfect. The further the reading deviates from 0vdc the worse the conductor is.

I always start with both leads at the battery. Watch meter while cranking. Should not drop much below 12vdc.

If good at battery, move the neg lead to the block. Crank again and look for the same voltage. This will confirm/condemn negative battery cable.

Now move the pos lead to the starter post. Crank again and check voltage. This will confirm/condemn pos cable.

Good meters have a min/max button u can use to capture the highest/lowest readings so you don't have to be able see the meter while cranking.

 

[iamtherealJayy]

Could my issue be a ground issue? With 6+ shims being under one side of the starter? I have a starter brace on the way that should add another ground to the block and support the starter. I’m currently at work I’ll have to check the voltage later and have someone else crank the truck while I watch since I’ve just got a cheap hobo freight multimeter

 

[wlwarnke]

I wouldn’t suspect the shims as the bolts are making a good metal to metal path.

 

[AuroraGirl]

Carefully inspect the battery cables. They can be corroded inside the insulation where it’s hard to see.

If the battery load tests hood, before spending another dime do a simple voltage drop test.

Get a voltmeter, put the positive probe of the meter on the positive post of the battery. Put the NEGATIVE probe of the meter on the POSITIVE cable end AT THE STARTER. Crank the engine while looking at the meter. Whatever the meter reads is the voltage lost in the cable. If it’s more than a couple tenths of a volt, either the cable is undersized, or you have a bad connection somewhere.

You can do the same thing on the negative cable, just reverse the connections.

Another possibility: inspect the advance weights in the distributor. If they are corroded, they can stick in the advanced position. Remove the cap, twist the rotor, the rotor should snap back to it’s original position. If not, inspect, clean and lube the advance weights. If they are sticky, reset the timing once they are fixed.

Its funny you mention this.....
Jay remember when I harped on CHECK THE ADVANCE WEIGHTS about 50 times? If you never did and that was the issue Id die lol

 

[AuroraGirl]

Could my issue be a ground issue? With 6+ shims being under one side of the starter? I have a starter brace on the way that should add another ground to the block and support the starter. I’m currently at work I’ll have to check the voltage later and have someone else crank the truck while I watch since I’ve just got a cheap hobo freight multimeter

why exactly are there 6 shims? What kind of contact is your flywheel making on this starter.

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So your battery neg to your alt bracket. Thats your STARTERS GROUND. Because its so disconnected from your starter, literally, the corrosion at each connection of starter to bellhousing to block to head to intake to bracket to cable to battery,... you can clean those, find the voltage drop, or you can just add another ground. find a spot on the block you can put a bolt and lug on. Do it near the starter then run that to the bracket or to the battery.
Then your engine heads should have straps to the firewall.
Then the trucks core support or fender should have a connection to the frame and then battery. Then there should be a clean bus bar under dash

 

[iamtherealJayy]

The advance weights spring back to position when you’d told me to check, I haven’t checked that since on this truck, I went to check voltage today and multimeter read 0.28v but the truck still cranked slowly. Multimeter might taken retirement early not sure yet I was just tinkering around on my lunch break. My starter brace came in today I’ll be installing it tonight. There’s 6+ shims on the outer bolt to get a 1/8” drill it between ring gear and starter Bendix armature.

 

[scrap--metal]

Is it possible that you fixed one issue, your tach/radio cutting out and the warm ground cable problem, by redoing some electrical connections, and a separate problem exists?

A tired starter motor can slow down and progressively crank slower until it eventually won't crank at all. It's not always an immediate failure.

 

[iamtherealJayy]

Starter is maybe a year old, I had starter issues in the truck for a long time until I started to understand shimming it because it wasn’t engaging all the way

 

[scrap--metal]

Starter is maybe a year old

Sorry I missed that if it was previously mentioned. Maybe it is your battery??? It seems like you've replaced pretty much everything else in the system other than the battery and battery cables.

 

[iamtherealJayy]

I’m not sure whether battery is shot or multimeter retired early but I tried to check voltage and it said 0.28v but gauge inside showed maybe 9/10 before cranking and dropped off when cranking.

 

[AuroraGirl]

ZY

Starter is maybe a year old, I had starter issues in the truck for a long time until I started to understand shimming it because it wasn’t engaging all the way

YOU HAD HOW MUCH VOLTAGE DROP? .28? Is that the battery to the starter when doing a voltage drop test? Or ground cablE? EIther way thats a lot of resistance for a straight shot of heavy gauge

 

[AuroraGirl]

I’m not sure whether battery is shot or multimeter retired early but I tried to check voltage and it said 0.28v but gauge inside showed maybe 9/10 before cranking and dropped off when cranking.

Wait I think you are talking your multimeter on the battery. Get new leads and put a new 9v battery inside it incase its older. Also does it have auto range or is it a dial which you have to select each range

 

[iamtherealJayy]

Yes the multimeter directly to battery read 0.28v… it got uhm taken care of and I had to buy a new one. Battery reads 12.49 as is no load or anything I didn’t have time to test cranking yet