Random Starting/Starter Probs

[NickBarrFishing.com]

Hi,

I have been trying to figure this out...so here is my problem.

I have a 1995 3/4 ton with a 5 speed NV4500 with about 150K miles on it.

I go to start the truck, and sometime its starts right up, other times, I turn the key and I hear a big click and a bunch of little clicks afterwords in short succession.

My voltage is good. So I got it up on the lift, and I checked the grounds, all the grounds i could find were clean and well. The connections to the starter solenoid seemed in good shape and their grounds were good (Couldnt find where the small ground wire that leads up into a wiring harness went too though??)

So here is what I found.
>I can start my truck in neutral w/o the clutch being in? Is this normal for this truck, I have heard you can snip a wire and be able to start w/o clutch pressed

>Tapping the starter and solenoid did not help
>Starts at random times, ten tries, then it will start, or one time (How it is supposed to be), sometimes I have to push start (Pain in the arse)


So if my grounds seem to be ok, my gut tells me it is the solenoid. Anybody else have any suggestions?

I am in High School and taking advanced auto, so I know my way around an engine, but I am just starting to dive into diesel mechanics. Fishing is my passion, and hopefully future business path, but diesel trucks is my new found hobby, so I figured the truck I got would be a great beginner diesel.

 

[docdray]

battery cables good (remove boots from cable-battery connection). sounds like a bendix/solenoid issue- have someone get under truck by starter to hear if the starter is where clicking is. neutral clutch start is simply a safety switch, could bypass easily.

 

[Anubis]

that could be starter or switch or relay or solenoid on the starter.

I have this problem with a 12.7L detroit (delco starter and relays) 4 times and each time it was a different problem.

 

[JMJNet]

Well, start with the easy one. Do a load test on the battery one at a time. Voltage on batteries can be good but it can fail load test. Again, make sure it is one at a time. The part store can do it for you if you don't have a load tester which can be purchased from Harbor Freight for about $15.

Next, make sure all the connectors are good. The stock GM connectors are covered with rubber which sometimes after aging does not contact the battery terminal properly. Sometimes, cables are corroded inside and we don't know it.

 

[Odlaw]

Hi,

I have been trying to figure this out...so here is my problem.

I have a 1995 3/4 ton with a 5 speed NV4500 with about 150K miles on it.

I go to start the truck, and sometime its starts right up, other times, I turn the key and I hear a big click and a bunch of little clicks afterwords in short succession.

My voltage is good. So I got it up on the lift, and I checked the grounds, all the grounds i could find were clean and well. The connections to the starter solenoid seemed in good shape and their grounds were good (Couldnt find where the small ground wire that leads up into a wiring harness went too though??)

So here is what I found.
>I can start my truck in neutral w/o the clutch being in? Is this normal for this truck, I have heard you can snip a wire and be able to start w/o clutch pressed

>Tapping the starter and solenoid did not help
>Starts at random times, ten tries, then it will start, or one time (How it is supposed to be), sometimes I have to push start (Pain in the arse)


So if my grounds seem to be ok, my gut tells me it is the solenoid. Anybody else have any suggestions?

I am in High School and taking advanced auto, so I know my way around an engine, but I am just starting to dive into diesel mechanics. Fishing is my passion, and hopefully future business path, but diesel trucks is my new found hobby, so I figured the truck I got would be a great beginner diesel.

Did you check all the grounds? There are several on these trucks - the hardest to get to ones are on the passenger side rear of head, to firewall, then to frame.

If everything that has been mentioned here has been checked and is good, you could always yank the starter and have it tested for free at any auto parts house.....like you, I suspect the solenoid too - and if it's happening as often as you say it is, it should show up in the bench test.

Good luck.
Smitty

 

[Mudbath]

Well, start with the easy one. Do a load test on the battery one at a time. Voltage on batteries can be good but it can fail load test. Again, make sure it is one at a time. The part store can do it for you if you don't have a load tester which can be purchased from Harbor Freight for about $15.

Next, make sure all the connectors are good. The stock GM connectors are covered with rubber which sometimes after aging does not contact the battery terminal properly. Sometimes, cables are corroded inside and we don't know it.

X2

 

[NickBarrFishing.com]

I took it into the shop today at school, me and my auto teacher got started with the problem.

>We did a voltage drop test checking for bad grounds. The 2 main grounds from the batteries were checked, no voltage drop.

>The positive battery connection that runs all the way to the starter we did a voltage drop test.
-When the truck starts, it is getting 12 volts to the starter
-when it would not start, the starter would only be getting 8 volts or so.
-This would happen randomly, sometimes it will get 12 and start, sometimes it would get 8 and not start and just click.

So we are working backwards through the ignition system to find the problem.

The only ground I am unsure of is the small little ground wire the runs from the solenoid up into a casing of wire, but I believe it comes out and it grounded on the rear passenger intake bolt, which I took off and cleaned.

IT WAS ABLE TO START EVERY TIME BY JUMPING THE STARTER WITH A SCREWDRIVER, so we know the solenoid is probably not the issue.

SO: We are narrowing it down to a few things in the ignition circuit. Either a bad Ignition switch, A bad safety switch, or a bad connection inbetween. I was surprised that there is no relay in the system. So we are going to test those things tomorrow.

 

[treegump]

IT WAS ABLE TO START EVERY TIME BY JUMPING THE STARTER WITH A SCREWDRIVER, so we know the solenoid is probably not the issue.

If you are jumping the starter with a screwdriver, aren't you bypassing the solenoid? If I'm thinking correctly, and you are bypassing the solenoid, then how do you know that the solenoid is probably not the issue?

 

[WarWagon]

GM is famous for ign switches going out on recent models. You could justify the ign switch to your teacher at this point. Simply take the old one apart and look for burnt contacts to prove it. While the new one eliminates the problem.

Really... 8 Volts to the starter: problem found...

 

[96 OILBURNER]

>The positive battery connection that runs all the way to the starter we did a voltage drop test.
-When the truck starts, it is getting 12 volts to the starter
-when it would not start, the starter would only be getting 8 volts or so.
-This would happen randomly, sometimes it will get 12 and start, sometimes it would get 8 and not start and just click.

Is this 8 volts on the cable from the battery or from the ignition switch?

 

[ak diesel driver]

If you are jumping the starter with a screwdriver, aren't you bypassing the solenoid? If I'm thinking correctly, and you are bypassing the solenoid, then how do you know that the solenoid is probably not the issue?

Depends on which terminals you cross