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Engine won't start or turn over - UPDATED [message #344249] Sun, 16 June 2019 17:02 Go to next message
Russell K. is currently offline  Russell K.   United States
Messages: 178
Registered: October 2016
Location: Dunedin, Florida
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Senior Member
Our '78 403 will not start. I drove it home Friday. It started normally. I stopped for gas, and it started normally after that. On Saturday, all I did was generator maintenance, no work at all on the coach engine. On Sunday we got in it to take it back to storage and it won't start. The battery is fine. There is no "click" sound at the starter. I tapped the starter with a rubber mallet, still nothing. I read through this thread about a 455 that would not start.

http://gmc.mybirdfeeder.net/GMCforum/index.php?t=msg&th=41398&goto=336892&rid=5215#msg_336892

I tilted the steering wheel all the way forward per Jim Hupy's suggestion, still no start.

The headlights do not dim when I try to start it.

I jumpered the double purple plug to bypass the neutral safety switch per the Starting Circuit Diagnosis chart on page 6Y-62 of the maintenance manual. Still nothing.

I am ordering a new starter, but I'm not convinced that is the problem. How to I check the rod that extends down the steering column from key mechanism? Any other suggestions?



1978 Eleganza II, Dunedin, Florida

[Updated on: Fri, 21 June 2019 18:57]

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Re: [GMCnet] Engine won't start or turn over [message #344251 is a reply to message #344249] Sun, 16 June 2019 17:18 Go to previous messageGo to next message
jimk is currently offline  jimk   United States
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Registered: July 2006
Location: Belmont, CA
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Senior Member
Use a steel hammer on the starter.
Rubber mallet does not produce the shock type impact.
Check you neutral switch.

On Sun, Jun 16, 2019 at 3:03 PM Russell Keith via Gmclist <
gmclist@list.gmcnet.org> wrote:

> Our '78 403 will not start. I drove it home Friday. It started normally. I
> stopped for gas, and it started normally after that. On Saturday, all I did
> was generator maintenance, no work at all on the coach engine. On Sunday
> we got in it to take it back to storage and it won't start. The battery is
> fine. There is no "click" sound at the starter. I tapped the starter with
> a rubber mallet, still nothing. I read through this thread about a 455
> that would not start.
>
>
> http://gmc.mybirdfeeder.net/GMCforum/index.php?t=msg&th=41398&goto=336892&rid=5215#msg_336892
>
> I tilted the steering wheel all the way forward per Jim Hupy's suggestion,
> still no start.
>
> The headlights do not dim when I try to start it.
>
> I jumpered the double purple plug to bypass the neutral safety switch per
> the Starting Circuit Diagnosis chart on page 6Y-62 of the maintenance
> manual. Still nothing.
>
> I am ordering a new starter, but I'm not convinced that is the problem.
> How to I check the rod that extends down the steering column from key
> mechanism? Any other suggestions?
>
>
> --
> Russell Keith,
> 1978 E2 "Harry" 403 (still carbureted), Danny Dunn Tranny, Thorley, Stock
> Brakes w/Remote Vacuum Brake Booster, Quad Bags, Dakota Digital Dash, 6.5 kW
> Onan, Dunedin, Florida
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>


--
Jim Kanomata
Applied/GMC, Newark,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
Re: Engine won't start or turn over [message #344256 is a reply to message #344249] Sun, 16 June 2019 18:02 Go to previous messageGo to next message
jhbridges is currently offline  jhbridges   United States
Messages: 8412
Registered: May 2011
Location: Braselton ga
Karma: -74
Senior Member
He's already bypassed the safety switch on the column. Take your ten foot #16 clip cord - you DO have one don't you? - and clip it on the terminal where the small wire is connected, touch the other end to the battery hot terminal and see if it spins. Report back Smile If it spins, find where it isn't making it from the battery to the solenoid. Usually it's the switch located at the bottom of the steering column. Chuck Boyd understands steering columns, ask him how to test.

--johnny


Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons. Braselton, Ga. I forgive them all, save those who hurt the dogs. They must answer to me in hell
Re: Engine won't start or turn over [message #344259 is a reply to message #344249] Sun, 16 June 2019 18:08 Go to previous messageGo to next message
jhbridges is currently offline  jhbridges   United States
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Registered: May 2011
Location: Braselton ga
Karma: -74
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I wasn't clear. The 'small terminal' is the small terminal on the starter solenoid.\


--johnny


Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons. Braselton, Ga. I forgive them all, save those who hurt the dogs. They must answer to me in hell
Re: Engine won't start or turn over [message #344260 is a reply to message #344249] Sun, 16 June 2019 18:16 Go to previous messageGo to next message
Matt Colie is currently offline  Matt Colie   United States
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Registered: March 2007
Location: S.E. Michigan
Karma: 7
Senior Member
Russell K. wrote on Sun, 16 June 2019 18:02
Our '78 403 will not start. I drove it home Friday. It started normally. I stopped for gas, and it started normally after that. On Saturday, all I did was generator maintenance, no work at all on the coach engine. On Sunday we got in it to take it back to storage and it won't start. The battery is fine. There is no "click" sound at the starter. I tapped the starter with a rubber mallet, still nothing. I read through this thread about a 455 that would not start.

http://gmc.mybirdfeeder.net/GMCforum/index.php?t=msg&th=41398&goto=336892&rid=5215#msg_336892

I tilted the steering wheel all the way forward per Jim Hupy's suggestion, still no start.

The headlights do not dim when I try to start it.

I jumpered the double purple plug to bypass the neutral safety switch per the Starting Circuit Diagnosis chart on page 6Y-62 of the maintenance manual. Still nothing.

I am ordering a new starter, but I'm not convinced that is the problem. How to I check the rod that extends down the steering column from key mechanism? Any other suggestions?
Russel,

It is not likely to be the starter or solenoid. If the solenoid is getting the signal it will click. If you don't hear the click, a hammer is not likely to be a help. A conformance check at this point can be to short the terminals on the back of the solenoid. If you have HEI, this will not start the engine, but it may crank it and do an electric burn to what ever you used for the test. If that cranks, the starter is good.

The NSS is between (electrically) the ignition switch and the solenoid. Check from the hot side of that to the column with a test light. Unfortunately, both sides of that switch are the same color, so I cannot tell you which is the important one to test. But, if neither of those two make the light come on when you turn the key then dollars to donuts the switch on the column is at least out of adjustment. This only happens when a coach is used (all the time).

That would be my first bet. What I can't remember right off hand is which way you probably want to more the switch. If you don't mind crawling on the floor, the adjustment is easy. It is also easy to replace the switch if it has gone bad. That switch was used in GM product from about the turn of the last century until the turn to the current century so they are very available.

Having a spare starter isn't stupid either. They have been out of production for 40 years and ours was only used with the 425 transmission.

Matt


Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
Re: Engine won't start or turn over [message #344271 is a reply to message #344259] Sun, 16 June 2019 22:55 Go to previous messageGo to next message
Ken Burton is currently offline  Ken Burton   United States
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Registered: January 2004
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Johnny Bridges wrote on Sun, 16 June 2019 18:08
I wasn't clear. The 'small terminal' is the small terminal on the starter solenoid.\


--johnny
There are two small terminals on the starter solenoid. On a points distributor coach one terminal goes to the distributor and the other goes to the NSS and ignition switch for starting. On an HEI distributor coach, which your 1978 is, choose the terminal that has an existing wire going to it.


Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
Re: [GMCnet] Engine won't start or turn over [message #344272 is a reply to message #344271] Sun, 16 June 2019 23:26 Go to previous messageGo to next message
James Hupy is currently offline  James Hupy   United States
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Registered: May 2010
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Senior Member
To determine if you have an issue with your starter, connect a temporary
jumper wire from any known good positive 12 volt source to the starter
primary terminal on the solenoid where your wire from your ignition start
switch is connected. The minute you touch the jumper to a 12 volt positive
source, if the starter is good, it will crank.
Jim Hupy

On Sun, Jun 16, 2019, 8:56 PM Ken Burton via Gmclist <
gmclist@list.gmcnet.org> wrote:

> Johnny Bridges wrote on Sun, 16 June 2019 18:08
>> I wasn't clear. The 'small terminal' is the small terminal on the
> starter solenoid.\
>>
>>
>> --johnny
>
> There are two small terminals on the starter solenoid. On a points
> distributor coach one terminal goes to the distributor and the other goes
> to the
> NSS and ignition switch for starting. On an HEI distributor coach, which
> your 1978 is, choose the terminal that has an existing wire going to it.
> --
> Ken Burton - N9KB
> 76 Palm Beach
> Hebron, Indiana
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
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Re: [GMCnet] Engine won't start or turn over [message #344273 is a reply to message #344272] Mon, 17 June 2019 06:27 Go to previous messageGo to next message
tmsnyder is currently offline  tmsnyder   United States
Messages: 151
Registered: January 2014
Karma: -9
Senior Member
I recently replaced the starter on my '76 and can confirm that there's just the big wire from the battery which is obvious, and a single small wire to the solenoid which is not so obvious. The solenoid terminal is the one closest to the block and the wire is tucked in pretty tight around the backside of the solenoid.

I would check those wires and the connections. A test light on the solenoid terminal will also tell you if you have the 12v signal from the ignition switch making it down to the starter.



Todd Snyder, Buffalo NY 1976 Eleganza II
Re: Engine won't start or turn over [message #344282 is a reply to message #344249] Mon, 17 June 2019 09:46 Go to previous messageGo to next message
lqqkatjon is currently offline  lqqkatjon   United States
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right where the steering column touches the floor on the back side is your neutral safety switch. You said you by-passed it, it should be a heavier purple wire. If you hook a test light to that, you should see if your ignition switch is sending that 12v when you turn the key to "crank". then you can start going further down the circuit towards the starter itself, or back to the ignition switch.

that purple wire should go across the dash, enter in behind the fuse panel in the glove box, and that is a connection to the engine harness there(does not go through a fuse rather then just comes in behind the front panel where the fuses are and goes out to the harness. . it then leaves the backside of the fuse block into the harness in the passenger hatch, down the wire-loom that goes to the forward passenger side of the engine, where there is a T in the wireloom and exits and drops straight down by the fuel pump where it is routed along the oil cooler lines to the starter.( small terminal closest to block on solenoid).

so there are a few spots you can check to test that when you go to crank, it gets 12v. jack up the coach a bit on the cross member and remove the passenger side wheel liner gives you good access to those starter wires to put a test light to on the starter.



Jon Roche 75 palm beach EBL EFI, manny headers, Micro Level, rebuilt most of coach now. St. Cloud, MN http://lqqkatjon.blogspot.com/
Re: Engine won't start or turn over [message #344283 is a reply to message #344249] Mon, 17 June 2019 09:48 Go to previous messageGo to next message
lqqkatjon is currently offline  lqqkatjon   United States
Messages: 2324
Registered: October 2010
Location: St. Cloud, MN
Karma: 5
Senior Member
right where the steering column touches the floor on the back side is your neutral safety switch. You said you by-passed it, it should be a heavier purple wire. If you hook a test light to that, you should see if your ignition switch is sending that 12v when you turn the key to "crank". then you can start going further down the circuit towards the starter itself, or back to the ignition switch.

that purple wire should go across the dash, enter in behind the fuse panel in the glove box, and that is a connection to the engine harness there(does not go through a fuse rather then just comes in behind the front panel where the fuses are and goes out to the harness. . it then leaves the backside of the fuse block into the harness in the passenger hatch, down the wire-loom that goes to the forward passenger side of the engine, where there is a T in the wireloom and exits and drops straight down by the fuel pump where it is routed along the oil cooler lines to the starter.( small terminal closest to block on solenoid).

so there are a few spots you can check to test that when you go to crank, it gets 12v. jack up the coach a bit on the cross member and remove the passenger side wheel liner gives you good access to those starter wires to put a test light to on the starter.



Jon Roche 75 palm beach EBL EFI, manny headers, Micro Level, rebuilt most of coach now. St. Cloud, MN http://lqqkatjon.blogspot.com/
Re: Engine won't start or turn over [message #344294 is a reply to message #344249] Mon, 17 June 2019 15:01 Go to previous messageGo to next message
JohnL455 is currently offline  JohnL455   United States
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Registered: October 2006
Location: Woodstock, IL
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Senior Member
With a meter or even a test light and a friend to turn key, you can stop all the guessing and put away the hammer and actually troubleshoot.

John Lebetski
Woodstock, IL
77 Eleganza II
Re: Engine won't start or turn over [message #344295 is a reply to message #344283] Mon, 17 June 2019 15:06 Go to previous messageGo to next message
tmsnyder is currently offline  tmsnyder   
Messages: 151
Registered: January 2014
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Senior Member
I would start at the starter with a test light and see that A) the connection from the battery is good; clean and tight and B) that the 12V signal is getting to the solenoid. If they are both good, you know it's the starter. If one is missing, you can work back from there based on what is found. That's just me though, I like to use a process of elimination. Skipping back most of the way up the chain towards the ignition switch doesn't really tell you much imo.

But before that, I'd thump the starter body with a mini-sledge and see if it's just the brushes hanging. And if it is, have a good starter / alternator shop rebuild it. I just had mine rebuilt locally by a one-man shop in the Buffalo NY area for $75. New USA solenoid and brushes, cleaned up and painted. One day turn around. Cash or check only, no credit card. He said it was due, brushes were just about gone.


Todd Snyder, Buffalo NY 1976 Eleganza II
Re: Engine won't start or turn over - UPDATED [message #344403 is a reply to message #344249] Fri, 21 June 2019 19:07 Go to previous messageGo to next message
Russell K. is currently offline  Russell K.   United States
Messages: 178
Registered: October 2016
Location: Dunedin, Florida
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Senior Member
Thank you! Thank you! Thank you!
Thank you to everyone with the tips to help troubleshoot and repair my starting problem.

It wasn't the starter, it wasn't the neutral safety switch, it wasn't the wiring, IT WAS THE IGNITION SWITCH!

After going through the helpful tips you guys provided, and some additional reading, and some electrical troubleshooting with a meter, I found that the start position in the five-position ignition switch wasn't working.

I ordered a ACDELCO D1405B Ignition Starter Switch for a 1978 GMC K35 PICKUP 6.6L V8 through Rock Auto. It was a perfect match. I put it in tonight, and it started right up.

Thanks again for all the help. I am grateful beyond words for this forum and this GMC community!!!


1978 Eleganza II, Dunedin, Florida
Re: Engine won't start or turn over - UPDATED [message #344405 is a reply to message #344403] Fri, 21 June 2019 23:12 Go to previous messageGo to next message
C Boyd is currently offline  C Boyd   United States
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Good news.. make sure the switch is adjusted where it will operate with tilt in all positions.




Russell K. wrote on Fri, 21 June 2019 20:07
Thank you! Thank you! Thank you!
Thank you to everyone with the tips to help troubleshoot and repair my starting problem.

It wasn't the starter, it wasn't the neutral safety switch, it wasn't the wiring, IT WAS THE IGNITION SWITCH!

After going through the helpful tips you guys provided, and some additional reading, and some electrical troubleshooting with a meter, I found that the start position in the five-position ignition switch wasn't working.

I ordered a ACDELCO D1405B Ignition Starter Switch for a 1978 GMC K35 PICKUP 6.6L V8 through Rock Auto. It was a perfect match. I put it in tonight, and it started right up.

Thanks again for all the help. I am grateful beyond words for this forum and this GMC community!!!


C. Boyd
76 Crestmont
East Tennessee
Re: Engine won't start or turn over - UPDATED [message #344411 is a reply to message #344403] Sat, 22 June 2019 10:50 Go to previous message
Matt Colie is currently offline  Matt Colie   United States
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
Senior Member
Russell K. wrote on Fri, 21 June 2019 20:07
Thank you! Thank you! Thank you!
Thank you to everyone with the tips to help troubleshoot and repair my starting problem.
It wasn't the starter, it wasn't the neutral safety switch, it wasn't the wiring, IT WAS THE IGNITION SWITCH!
After going through the helpful tips you guys provided, and some additional reading, and some electrical troubleshooting with a meter, I found that the start position in the five-position ignition switch wasn't working.
I ordered a ACDELCO D1405B Ignition Starter Switch for a 1978 GMC K35 PICKUP 6.6L V8 through Rock Auto. It was a perfect match. I put it in tonight, and it started right up.
Thanks again for all the help. I am grateful beyond words for this forum and this GMC community!!!
Russell,

This is want the community likes to hear and what we are here to promote.

This is why we always start with the diagnostics...

Matt


Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
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