Voltage Drop Across Glow Plug Circuit

[Ray Erps "Diamon Girl " #]

Finally took care of my "slow cranking" problem.  I installed the glow plug solenoid shortly after I got the boat but unless conditions were perfect, seems like I always had to put the battery switch to "both" to get the motor started.  I debated on whether to install a separate cranking battery with short cables behind the motor or replace the #4 battery cables, as I figured the costs were going to be pretty close.  I opted to go the path of least resistance (work) and ran a #2 wire from the starter battery straight to the starter with its own "on-off" switch.  It's basically a permanently installed jumper cable.

Wow, what a diffence.  10 to 15 seconds on the glow plug preheat button and it fires right up.  My starter battery bank was two G27's.  Now I'll be able to pull one of them out and wire it into the house bank to increase the amp hours there.  WOW-what a difference.  I'm no longer a slow cranker.

Ray

[Jim Price]

Just another follow up on my experiences.  Along with changeing the initial starting sequence, I also added in a soleniod from NAPA.  We basically had to look through their parts manual to find what looked correct with right specs (they did not have the Ford parts in stock).  As usual, part number is on boat - will add later.  

Anyway, yesterday, air temp was 28 with 17MPH winds (nice chill factor), no start for 2 1/2 weeks - heated plugs 15 seconds; released; hit starter; turned one time maybe and running perfectly.  I am running 2 Group 31's deep cyle as house and start (third dedicated to refirdgerator). Volt meter reads 14+ initially; 12.5 heating and then about 12 when I switch to start.  What a difference! :cool:  Cape Dory owner with XP planning to do an Atlantic crossing next year is buying his solenoid and wire right now - says his will hardly ever ever start with 2 batteries.

[Stu Jackson]

GLOW PLUG SOLENOID

Vic

Don't know where your attachment is, but here is the link to the Projects page for this subject.  The wiring harness has NOTHING to do with this improvement, because even if you DO the wiring harness upgrade, you still need to do this one.

http://www.c34.org/projects/projects-glowplugs.html

The schematic is included in this updat that Mark Elkin recently made to the page.

It's one of the simplest and most useful upgrades you can make to any boat.

Stu

[shekinahsailor]

I've been following this thread but feeling it doesn't really pertain to me as I have a later model M35 and no starting problems.  However, the recent questions about "holding the start switch forward to heat the glow plug" put me in the "I don't know mode".  I've always put my start switch to "on", without holding it, waited about 15 seconds and pushed the start button.  Engine fires in about 3 seconds (warm weather) to  7 seconds (cold weather).  No complaints.  However, always looking for improvements, maybe I should be holding the key forward prior to releasing it back to "on" like others are mentioning.  I'm not at my boat to check this out.  Anyone with the later engines have an answer to this?

[Stu Jackson]

John

The issue is what turns your glow plugs on before you hit the start button.  If you don't have a separate glow plug button, like our older boats, then the glow plug "ON" may be the key in the turned position.  Turn the key all the way to warm the glow plugs, then release it, then hit the start button.

Stu

[Ray Irvine]

Stu is correct, with the standard M35 engine control panel, the glow plugs are only on when the key switch is held in the fully turned position.  The power is removed once the key is released.