Nothing happens when I turn the key

ktcnyc

ktcnyc

Member
Sep 14, 2020
99
13
8
Dingmans Ferry, Pa. and NYC
Hello Folks - I'm on a trip In Maine and suddenly nothing happens when I turn the key on my '77. No dash lights, totally dead. It will start with the
battery boost switch from the house batts and runs fine. The engine battery tests good and is getting a charge. I stopped at a Napa and changed out
the battery boost solenoid but no luck there. Something just blew or disconnected somewhere but what? Any help is greatly appreciated!
--
Kevin Cloutier -'77 Eleganza II-455, 6 disk brakes, Edelbrock carb, headers, , resident of NYC and Dingmans Ferry, Pa.
'72 MGB-GT & '73 MGB convertible
Member GMCMI since 8/20
 
Maybe corroded battery terminals; take them off and clean them. If not, follow the wires to the next connection(s) (hot and ground) downstream. Rinse
and repeat.

Or, first maybe try connecting a jumper cable from BAT+ to the chassis side of the boost solenoid. If it starts, something in between is open.
--
Bill Van Vlack
'76 Royale; Guemes Island, Washington; Twin bed, full (DS) side bath, Brazilian Redwood counter and settee tops,455, 6KW generator; new owner a/o mid
November 2015.
 
I second Bill's suggestion. Check and clean BOTH ends of BOTH battery cables. Also possibly one of the cables is corroded inside under the
insulation. If it starts on the house battery(s) then the problem has to be with the engine battery and its cables or connections.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
 
Fusible link wire between key and starter perhaps?
Loose or corroded battery terminals
Blown fuse

> I second Bill's suggestion. Check and clean BOTH ends of BOTH battery
> cables. Also possibly one of the cables is corroded inside under the
> insulation. If it starts on the house battery(s) then the problem has to
> be with the engine battery and its cables or connections.
> --
> Ken Burton - N9KB
> 76 Palm Beach
> Hebron, Indiana
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
>
 
I have good voltage from the engine batt to the solenoid - cables are good and clean.

Where is this fusible link between the key and the starter?

What "fuse would be blown"?
--
Kevin Cloutier -'77 Eleganza II-455, 6 disk brakes, Edelbrock carb, headers, , resident of NYC and Dingmans Ferry, Pa.
'72 MGB-GT & '73 MGB convertible
Member GMCMI since 8/20
 
If the fusible link were blown, the House battery wouldn't work either.

How do you know the chassis voltage at the solenoid is "good"? A
voltmeter, used without engaging the starter can read full voltage even
though there's far too high resistance somewhere. I'm guessing the
resistance at the terminal on one of the battery cables is so high that is
dropping all the voltage when current tries to reach 200+ Amps. I had that
happen a couple of years ago -- the positive battery cable at the battery
looked great and had a clean, well-maintained connection to the battery,
but when I pulled on the cable, it slipped right out of the terminal.

Ken H.

> I have good voltage from the engine batt to the solenoid - cables are good
> and clean.
>
> Where is this fusible link between the key and the starter?
>
> What "fuse would be blown"?
> --
> Kevin Cloutier -'77 Eleganza II-455, 6 disk brakes, Edelbrock carb,
> headers, , resident of NYC and Dingmans Ferry, Pa.
> '72 MGB-GT & '73 MGB convertible
> Member GMCMI since 8/20
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
>
 
Neutral Safety Switch?
http://www.gmcmhphotos.com/photos/g5493-gmc-cranking-improve-for-free.html

-----Original Message-----
From: kcloutier [mailto:kcloutier]
Sent: Friday, July 30, 2021 7:48 PM
To: gmclist
Subject: [GMCnet] Nothing happens when I turn the key

Hello Folks - I'm on a trip In Maine and suddenly nothing happens when I
turn the key on my '77. No dash lights, totally dead. It will start with the
battery boost switch from the house batts and runs fine. The engine battery
tests good and is getting a charge. I stopped at a Napa and changed out
the battery boost solenoid but no luck there. Something just blew or
disconnected somewhere but what? Any help is greatly appreciated!
--
Kevin Cloutier -'77 Eleganza II-455, 6 disk brakes, Edelbrock carb, headers,
, resident of NYC and Dingmans Ferry, Pa.
'72 MGB-GT & '73 MGB convertible
Member GMCMI since 8/20
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
 
Kevin,

An often ignored place for poor connections is the ground path. Check that before you spend any more money. Those flat braid cables can dissolve in
a corrosive environment like the east coast. Care to guess how I know??

If your diagnostic data is correct, you just have a bad connection somewhere. I hope you kept the good boost contactor that you took out.

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
 
You did not need to replace boost contactor as that is just a stud pass through junction on the engine positive side.
You say dash lights no go. Try the headlamps and report back. Not sure about the validity of your engine battery “test”. Digital battery load
testers are USUALLY accurate but not always. You could have an intermittent cell which can be a bugger to diagnose at times.
Since BOOST works, logic says the problem is on the hot side before the boost junction. Positive battery cable to boost junction or battery itself.
Could also be the Neg cable or connections on engine battery side. You don’t need to look elsewhere as Boost starts it.
--
John Lebetski
Woodstock, IL
77 Eleganza II
 
Try doing a voltage drop on the positive engine cable. B+ to starter terminal. Have some one crank it over and look at your meter. If you have more than .2 volts ,any reading on the meter, you have a bad cable or connection. Red lead on meter to battery and black lead on starter.

Sent from Mail for Windows 10

From: John R. Lebetski
Sent: Saturday, July 31, 2021 7:35 AM
To: gmclist
Subject: [GMCnet] Re: Nothing happens when I turn the key

You did not need to replace boost contactor as that is just a stud pass through junction on the engine positive side.
You say dash lights no go. Try the headlamps and report back. Not sure about the validity of your engine battery “test”. Digital battery load
testers are USUALLY accurate but not always. You could have an intermittent cell which can be a bugger to diagnose at times.
Since BOOST works, logic says the problem is on the hot side before the boost junction. Positive battery cable to boost junction or battery itself.
Could also be the Neg cable or connections on engine battery side. You don’t need to look elsewhere as Boost starts it.
--
John Lebetski
Woodstock, IL
77 Eleganza II
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
 
In the last month or so I have seen people having starting problems have the starter battery cable connected to the boost side (Left) of the boost
solenoid. This will have the house battery as the starting battery. The engine will start but only if the battery has a good charge. The alternator
will only be charging it through the isolator. Hitting the boost will engage the engine battery to start and everything will seem normal until you try
and start the engine again.

--
Tom McManus
1977 Royale

Chesapeake VA
 
Why would they have it wired so it starts from the house battery? That doesn’t make sense to me. There are a lot of reasons it should start from the engine battery.

Emery Stora

>
> In the last month or so I have seen people having starting problems have the starter battery cable connected to the boost side (Left) of the boost
> solenoid. This will have the house battery as the starting battery. The engine will start but only if the battery has a good charge. The alternator
> will only be charging it through the isolator. Hitting the boost will engage the engine battery to start and everything will seem normal until you try
> and start the engine again.
>
> --
> Tom McManus
> 1977 Royale
>
> Chesapeake VA
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
 
As has been stated by several posters and me here, the circuits are the same when starting on the house or the engine battery. The ONLY difference
between in the two scenarios is the engine battery and it's cables. So forget looking for fuses, switches, boost solenoid, etc.

You need to take voltage readings when the key is turned to the start which puts the engine battery under load. Use the same ground reference for
your meter that the starter is using (the engine block).

I strongly suggest that this is a battery to engine connection problem or the battery itself. I have experienced in the past where the connections
are visually clean, even wire brushed clean, but not electrically clean and still did not work. You can prove all of this by using your meter and
referencing all of your readings to engine block ground. Then only take readings while the key is turned and held in the start position.

All of the above assumes that the coach is wired in the OEM configuration with no modifications to engine and house battery electrical systems.

Do not throw any parts at this until you have proven with your meter what the problem is.

Ken B.

> I have good voltage from the engine batt to the solenoid - cables are good and clean.
>
> Where is this fusible link between the key and the starter?
>
> What "fuse would be blown"?

--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
 
John- You were so right in the basic logic -
"Since BOOST works, logic says the problem is on the hot side before the boost junction. Positive battery cable to boost junction or battery itself.
Could also be the Neg cable or connections on engine battery side. You don’t need to look elsewhere as Boost starts it. "

It was a very funky, dirty connection to the ground battery terminal connector.
Moby (my coach) fired right up!

Many many thanks and to all that chimed in

KC

--
Kevin Cloutier -'77 Eleganza II-455, 6 disk brakes, Edelbrock carb, headers, , resident of NYC and Dingmans Ferry, Pa.
'72 MGB-GT & '73 MGB convertible
Member GMCMI since 8/20
 
Great. You got it and hopefully are on your way.

Ken B.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
 
doesn’t make sense to me. There are a lot of reasons it should start from the engine battery.

Emery Stora

Because it works and when something works, life go on until it doesn't. I had a guy that thought that the boost solenoid was the starter solenoid. He
had owned too many FORDS. I have told more than one owner to back away from the vehicle and call a professional.
--
Tom McManus
1977 Royale

Chesapeake VA
 
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