Starter solenoid volt requirement


#1

why is there only 11.93 volts getting to the solenoid when the battery is producing 12.3 volts?


#2

A good fully charged battery should be up around 12.6 volts.

There will be a voltage drop on any electrical item; not only the solenoid. This is normal and caused by resistance in various wire connectors, current load, etc.

So what is the car doing or not doing?


#3

when i turn the ignition switch all i hear is a click from the solenoid. It’s a brand new starter/solenoid. I checked if the engine has seized and it has not. I had the battery re-charged and checked at a local parts store and it’s good. It’s strong enough to start the motor.


#4

a local parts store and it’s good. It’s strong enough to start the motor.

It may be strong enough, but if one of the battery cables is not clean and tight, it will not be enough. Remove all ends of all battery cables (one at a time) and clean them and put them back on nice and tight.


#5

It sounds like either the solenoid contacts are bad or the starter motor it self isn’t working. Try bypassing the solenoid using a jumper cable to see if the starter will work then.


#6

Up to a volt drop shouldn’t cause any problems. The starter solenoid will usually energize at as little as 9 volts. Loosen and re-snug the nut holding the wire to the solenoid. Turn the ignition key to START. Does the starter solenoid energize? Check that the large cable, on the starter is clean and tight. The best way would be to disconnect the cable, sand its end, and reattach. Do the same to the battery cables.


#7

What kind of car are we even talking about?

With a new starter and a KNOWN good battery, that leaves either the cables or a distribution terminal at fault.

I hope whoever tested the battery did it properly.
A proper test means a minimum of 30 minutes on the charger and preferably an hour.

A load of 3 X the normal starter draw (usually 300-350 amps) is applied for 15 seconds with a carbon pile and the battery voltage should remain at or above 10.2 volts.

If one applies a load and battery voltage drops below 10 then you have a junk battery.


#8

If the solenoid clicks, it is getting power. The solenoid has two wires on it; the little one is for the coil and comes from the ignition switch. This one appears to be OK. The big cable is the main power for the starter motor. When the solenoid clicks, it’s contacts make connection and should be supplying power to the motor from the big cable. Check for voltage on that terminal. Some have circuit overload protection and if it’s blown, you won’t have power at the big cable connection. If you do have battery voltage there, then check the negative cable going from the battery negative to the engine block for corrosion at either end. Last check is at the starter motor terminal. When the solenoid clicks, there should be voltage at this terminal. If not, the solenoid is defective.


#9

the vehicle is a 1987 nissan pickup truck with a 2.4 liter engine and manual transmission. When the charging and checking of the battery was started it had 595 CCA and 12.21 volts and ended with, after 40 minute test/charge, 602 CCA and 12.53 volts. I must admit that it looks like the previous owner change the positive battery cable some time back but the negative cable looks original and when i cut back on some of the insulation of it where it terminates at the battery post it does look like corrosion has gone into the rest of strands beyond where it connects to the battery.


#10

If those CCA and voltage figures are something they gave you after charging the battery, be advised those figures are meaningless.
12.53 volts is fine, but what is the voltage with a load applied? Or was a load even applied?
The 12.53 may be nothing more than a surface charge that disappears quickly.

Unless a load was applied as I mentioned, you may still have a bad battery.

Another possibility could be this. You state that you hear a starter solenoid click sound. Is that click the starter solenoid, OR, if your truck has a manual transmission, is it the click of an interlock relay?

The way to check this is with a test light at the small wire at the starter solenoid. If there is no power there when cranking then it’s probably a faulty interlock relay. If there is power at that wire then it falls back on the battery cables.

Still puzzled a bit about this battery test though.


#11

i think that the battery is ok. I am going to replace the battery cables as the negative cable appears to have corrosian up into the strands of the wire when i cut back the insulation of the cable. The cable looks like it’s original equipment which means its 20 years old. I will let you know of the result.