1977 no-start diagnosis.

It seems that it should be simple enough, but I"m having problems.
I don't know why, but apparently the PO of this truck had the positive battery cable routed into the cab and connected to the starter. OK body
mounted batt, that's fine --- then he had a black cable (presumably negative - but no battery connection of any type on the other end) also attached to the large terminal on the starter. ???
Well the OEM side-post terminals came with the truck so I hooked up the positive to the large starter solenoid terminal, and to the alternator. I then attached the negative to a free bolt on the intake, and to the body. I'm not 100% on the body connection, I haven't checked for continuity and didn't take extreme measures to make sure it was connected. Don't think it would make a difference though???
So I hook up a fully charged deepcell battery to my wires with some starter cables - as the deepcell was not a side post battery. Well I turn the key and nothing happens, no click no nothing.
I tried connecting the power terminal on the solenoid to the other switched terminal with a screw driver with no luck? I attached a wire directly to pos and touched it to the smaller terminal (start apparently) and it didn't crank. The only thing that happened is all of a sudden there was apparently a dead short and the batt terminals got very hot and the neg terminal melted :-( No idea why it did - I had it hooked up like that before, and did the same after - no melty....?
My thoughts are; Faulty Ignition Switch - but the screw driver technique should have solved this - right? P/N switch failure - but the screw driver technique should have solved this - right? Bad solenoid - but touching power terminal to the "strap" that goes into the starter did nothing.
The heat shield/tube that carries the 3 wires that run to the starter area go as thus; Red: Large power terminal. Black: Small switch terminal Light tan/peach: Runs back along the frame apparently - goes to no where. Maybe for a fuel pump? Does this vintage have an electric fuel pump?
First time I've started in on something like this - being mid resto it's so bare. The spark plugs tell the story that it's been started before so it should run again. What am I missing??
GMC Gremlin
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Sorry 1977 K5 Blazer 350/350/203
GMC Gremlin

starter
switched
all
the
so
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Start from scratch WRT battery connections. You should have:
1) Positive to starter. 2) Positive to Alternator 3) Positive to distribution center
4) Battery negative to ENGINE BLOCK GROUND. WTF is it doing on the intake manifold? 5) Battery negative to body ground. 6) Grounding strap between frame and body.
Before you try and turn this thing over, pre-lube the motor and attempt to MANUALLY turn the crank witha breaker bar. If it's seized a power start will really booger things up.
I would also remove the starter and bench-test it. If the starter is FUBAR it will also cause all sorts of problems.
Doc
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I
body.
and
it
key
same
solved
area
where.
Check
Check
No check. Half of it isn't there if I recall.....

intake
Being attached to something on the engine block - exactly like it is OEM on my 1990 GMC F/S Jimmy that I copied.....................................................

Check
Maybe check.

Changed oil just for fun. It was full of gassoline. Changed oil filter too. (I think it was because it was on a very steep incline nose-down)

Done that - also put some oil in each cylendar and let it sit over night. Even thought about pulling the dizzy and running the oil pump w/ a screw driver....

FUBAR
I'm thinking I'll have to head in this direction. Right now I have all the spark plug wires off (didn't like routing) and plugs out - I'm just looking to get some crank and move onto the next.

GMC Gremlin
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that's the OEM conection... it's that way on my '88 K2500, my dad's '90 C2500, and my bro's '93 C1500 and none of of us have any starting problems, even at -20F ( well tested last January-Febuary)
-Bret
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wrote:

No shit eh? Never seen that before....................
Doc
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Heck there were a couple of years where the negative cable was mounted to the Alternator adjusting bracket, back in the day of V-belts, and with a self tapping bolt at that.
Whitelightning
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yep.... mine's attached to an intake manifold stud bolt, 2nd or 3rd one in.
-Bret
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I was thinking I might have to do that, but I didn't want to as I feared coolant leaks into the engine. Then I thought about the coolant neck and saw this beautiful bolt doing nothing but looking like I should attach my neg battery cable too it!
GMC Gremlin
wrote:

the
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wrote:

unless you've got a ground cable that's waaaaaay too short ( or you're talking about replacing a stud w/ a stud bolt) I wouldn't worry about it. I suppose you could use that water neck bolt.. my truck uses one for the ECM ground and the other for a pencil brace. ( don't get me started on what a stupid stupid idea that was in an AL intake manifold.) but I'd look for a place that bolts directly into either the head or the block.
-Bret
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sounds like the starter is seized or internally shorted
take it off and get it tested, alternator too
then wire it:
Batt + to starter (BIG cable) Batt + to alternator Batt + also goes thru a couple fusible links at the starter into red wires (one of these may go to alternator instead of a direct battery-to-alternator connection)
Batt - to engine block-BIG cable; ( water pump bolt is good, or use a 'stud-bolt' in one of the exhaust manifold bolt holes) Batt - to body with at least a # 8 stranded wire Body to engine block with at least a # 8 stranded wire
Use as fresh battery

starter
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I
body.
and
it
key
same
solved
area
where.
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your post said no turn over when shortind +12v to the starter solenoid. that should click or the starter should turn over. Sounds like a bad STARTER SOLENOID to me. old john

starter
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the
so
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