Starter thermal interlock
Thread Starter
Instructor
Joined: Apr 2001
Posts: 140
Likes: 0
From: Las Vegas NV
Starter thermal interlock
When my engine is hot ('74 454), I can't start it, full charge on battery, good connection, etc. I've checked all the obvious factors. When its cool, it behaves perfectly normally.
I'm thinking a thermal interlock on the starter solenoid. But, is that interlock on the starter motor, or the starter solenoid?
Anyone else have this problem, and have an alternative viewpoint?
'74 454, original starter, original everything, except MSD ignition, Hooker Sidemounts.
Thanks!
David :cheers:
I'm thinking a thermal interlock on the starter solenoid. But, is that interlock on the starter motor, or the starter solenoid?
Anyone else have this problem, and have an alternative viewpoint?
'74 454, original starter, original everything, except MSD ignition, Hooker Sidemounts.
Thanks!
David :cheers:
Le Mans Master
Joined: Mar 2002
Posts: 7,456
Likes: 2
From: Coming home from Luckenbach Texas
Re: Starter thermal interlock (djlangford)
Normally, we only hear about this in the summer. But seeing as how you're in one of the few places in the country hotter than my locale right about now...
You're suffering from starter heat soak. Very common. One fix is a shorter solenoid spring (AC Delco 1958679). This fixed my problem. I'm not sure if the big block starter solenoid is the same as my small block unit, however.
Another is a heat shield blanket around the alternator -- not the best fix in my opinion.
Finally, another very good fix is a gear reduction starter. Look in Jegs or Summit Racing catalogs -- you'll find 'em. :yesnod:
You're suffering from starter heat soak. Very common. One fix is a shorter solenoid spring (AC Delco 1958679). This fixed my problem. I'm not sure if the big block starter solenoid is the same as my small block unit, however.
Another is a heat shield blanket around the alternator -- not the best fix in my opinion.
Finally, another very good fix is a gear reduction starter. Look in Jegs or Summit Racing catalogs -- you'll find 'em. :yesnod:
Intermediate
Joined: May 2002
Posts: 41
Likes: 0
From: Topsfield MA
Re: Starter thermal interlock (djlangford)
Hi,
I had the same problem with my 78 small block. The heat soak problem had damaged the starter beyond repair, so I replaced it and covered it with a thermal blanket to protect & prevent reoccurance.... As you know, it can be pretty embarassing to drive up to a gas station, fill-her-up with 93 octane, then 'click' and no start.
Good luck,
I had the same problem with my 78 small block. The heat soak problem had damaged the starter beyond repair, so I replaced it and covered it with a thermal blanket to protect & prevent reoccurance.... As you know, it can be pretty embarassing to drive up to a gas station, fill-her-up with 93 octane, then 'click' and no start.
Good luck,
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
Re: Starter thermal interlock (djlangford)
I really do wish the 'heat soak' theory of starter motors would just go away quietly.....what you have is an electrical problem....you need clean and re secure all your wiring....unless you have a header closer than say one inch to the starter motor, then i'ts possible to fry the internals with heat...but as long as the header pipe is not that close...you'r fine....you may have a bad starter, or solenoid...just swap the unit for the heavy duty one at a parts house....one with lifetime guarantee.....check the grounds from engine to frame under pass side engine mount....and under the battery compartment for negative lead.....and on starter itself for positive lead....and of course see the solenoid terminals are worth a damn, as the wire ends.....
also check you may have a bad neutral safety switch....one of the first thing I jumper out on my cars......i just go direct to solenoid from ignition switch....
GENE
GENE :D
also check you may have a bad neutral safety switch....one of the first thing I jumper out on my cars......i just go direct to solenoid from ignition switch....
GENE
GENE :D
Pro
Joined: Dec 2002
Posts: 560
Likes: 1
From: Mooresville NC
Re: Starter thermal interlock (mrvette)
I had the same exact problem with my '79, 350. I took advice from a mechanis freind to change the solenoid at $29 for a "heavy duty" one. Spent about an hour replacing it. No luck at the fix. I finally just went to Autozone and bought a brand new starter with the "heavy duty" solenoid for $36. Another hour and it was fixed. BTW I also installed a Moroso starter heat shield. No more embarrassing waits at the gas station or local food mart.
Burning Brakes
Joined: Aug 2002
Posts: 1,090
Likes: 8
From: Indianapolis Indiana
Re: Starter thermal interlock (djlangford)
I've had my '68 327 about 15 years and have put 3 or 4 new starters on it for this problem. Bought a wrap around heat shield last year but haven't installed it yet because the design of it looks like you could have an electrical short develop.
