Cockpit instrument panel works sometimes

[ChrisW]

Just want to say thanks again to everybody for their help. There is a lot of good information here, and I have enough stuff to keep me busy for a while. I am a little bit unclear on a few things at the moment, but I'm sure if I reread all the information posted here I will find it or figure it out.

[KWKloeber]

"Please do not hesitate to" ask for clarifications!  We've got your back. 

[ChrisW]

"Please do not hesitate to" ask for clarifications!  We've got your back. 

The key switch you recommended says it is rated for 10 amps run and 5 amps start.  I don't have a DC ammeter that can handle over 10 amps.  So I had an extra inline fuse holder and wired it into the power wire to the key switch.  I put a 15 amp fuse in it.  Turning the key to preheat blew the fuse in one second.  You recommended putting in a 30 amp fuse, but can that key switch handle 30 amps?

I think I want to get rid of that engine mod you were talking about and power the glow plugs directly.  I don't trust it.  Do I just hook that grey wire that goes into the engine near where the fuel line goes in to the S terminal of the key switch?

[KWKloeber]

"Please do not hesitate to" ask for clarifications!  We've got your back. 

The key switch you recommended says it is rated for 10 amps run and 5 amps start.  I don't have a DC ammeter that can handle over 10 amps.  So I had an extra inline fuse holder and wired it into the power wire to the key switch.  I put a 15 amp fuse in it.  Turning the key to preheat blew the fuse in one second.  You recommended putting in a 30 amp fuse, but can that key switch handle 30 amps?

I think I want to get rid of that engine mod you were talking about and power the glow plugs directly.  I don't trust it.  Do I just hook that grey wire that goes into the engine near where the fuel line goes in to the S terminal of the key switch?

Chris you ID'd one of the issues with the way CTY had Seaward configure some panels.  My M-25 panel is key off-->ON-->start (low amps) and preheat (higher amps) is a push-button.  Some M-25/XP panels were key off-->on, and PB preheat and PB start.  But, per Seaward, it changed the configuration over years because owners complained about start sequences -- took two hands instead of one.  I don't gettit, but that's why there are different configurations.

There's PB sws rated for 35 amps, but not a key sw that high.  That said, the start position is start+ignition. so 10+5=15a. 
rated.  The glow plugs draw 6a x 3 = 18 amps (give or take.)  You might want to use the plastic case CH #850 sw, rated 15+5=20a in the start position.

All that said, the preheat relay mod should draw low amps and *should** not blow a 15a fuse.  I'm guessing maybe 2-3a for the coil on that relay?  So if you are pulling 15+, there's something wrong, either in the relay itself or in the wiring.

Yes.  To power the preheat w/o the relay, the white #10 wire goes directly to the #3 glow plug.  Besides being simpler, KISS, that way is a little easier on your glow plugs so they last longer (slightly less voltage than 13-14v direct from the battery.)  The "downside" (if you consider it one) is that longer preheat time (+10-15 seconds) is needed.

[KWKloeber]

Chris

I found specs on the seadog switches and, interestingly, it's claimed to be 15a ignition and 30a ignition/start.  I never thought of seadog as the gold standard, as Cole Hersee is, but..... 
When you replaced your switch did the gauges work, or was there an issue from the get-go?  I wonder if the rating on the CH may be conservative or if the seadog overstated?

Manufacturers play all sorts of games (figures lie and liars figure.)  So I also wonder if the stated ratings are "contact make", "contact break" or "contact made" ..... we know it ought to be the lowest one, but........

If you use a "magneto" type ignition switch the I and S are not tied together, so when preheating ('start) the only current thru the contacts is the glow plugs (other loads are disconnected until the key goes back to the 'run' position.)  Both SD and CH should have that type.

[Ron Hill]

ChrisW : You need to look in Critical Updates, WiKi & Mainsheet tech notes --- LOOK FOR Glow Plug Solenoid upgrade.

That way all the Hi amps needed to heat the glow plugs stay down at the engine and do not flow to the key switch thru its marginally sized wiring!!

Great articles in those Mainsheet tech notes in WiKi and Critical Upgrades!!!

A few thoughts

[ChrisW]

Chris

I found specs on the seadog switches and, interestingly, it's claimed to be 15a ignition and 30a ignition/start.  I never thought of seadog as the gold standard, as Cole Hersee is, but..... 
When you replaced your switch did the gauges work, or was there an issue from the get-go?  I wonder if the rating on the CH may be conservative or if the seadog overstated?

Manufacturers play all sorts of games (figures lie and liars figure.)  So I also wonder if the stated ratings are "contact make", "contact break" or "contact made" ..... we know it ought to be the lowest one, but........

If you use a "magneto" type ignition switch the I and S are not tied together, so when preheating ('start) the only current thru the contacts is the glow plugs (other loads are disconnected until the key goes back to the 'run' position.)  Both SD and CH should have that type.

Yes, after replacing the switch the gauges do work.  I wonder if the problem could have just been corrosion in the key switch?  I will admit that I probably did not seal the panel well when I replaced the switch about six months ago.  In fact, I did not use any sealant, just screwed the panel back in.  I know better now.

[ChrisW]

I verified that the key switch is already hooked up directly to glow plugs.  That relay box is actually hooked up to the engine start button.  I wonder why that is.  It's also burned out where the connection for the wire to the alternator is.  I don't know if I should replace it or not.

Also, I have an ammeter now and I measured the current for the glow plugs.  It was 30 amps (for 3 glow plugs).  Is that normal?

[KWKloeber]

[edit follows]

What wire is burned?   Pictures please!

PS, I am in the minority but consistently recommend against the preheat relay/solenoid mod. It's unnecessary.  It also adds several potential failures points that are not a good idea to add when the only reason to install it is to "save" 10-15 seconds of preheat time (and then sit at the dock for 10 minutes for the engine to warm up, readying lines, chilling the beer, etc.)  Buy a powerboat if 15 seconds is critical.

My OEM panel is:
HD (25 amp) PB switch --> preheat
Key --> start



Chis

Some owners installed a relay (or solenoid switch) to energize the starter solenoid directly, rather than thru the key switch.  It is uncommon but not unheard of.  The reason is that the original harnesses had an undersized "S wire" that energizes the starter solenoid.  A work or sticky solenoid, low battery voltage, excessive loss in the"S" circuit and you can see why there could be an issue getting the solenoid to pull in.  The "S" wire should be 10 gauge and all the connections/terminals in good shape -- then there isn't a need for that relay  (which adds complexity and additional failure points. i.e., KISS is better.)

The OEM glowplugs are listed at 6 amp each.

Are you saying that you have an ammeter on the panel (it *must* go)? 
Or you used a V-O-M to measure the preheat amp draw? 
I would look for a partial short somewhere in the circuit (chafed insulation?) that could be drawing excessive amps when turning the key switch. And check for a short to ground (it could be intermittent). Possibly there's a bad (shorted) glow plug check them individually -- the resistance thru each one should be about equal.

-k

[ChrisW]

What's a VOM?  I used a clamp on meter that I bought recently; no ammeter on panel.

I decided to take out all the wires and redo everything (except for the cables to and from the battery).  I bought the wire each individually instead of the harness from CD.  With shipping it was about $75.  So if there is a short somewhere I am not worried about it, as it will all be replaced. And I don't need the relay any more I guess since I have #10 yellow wire for starter.

I'll check the glow plugs. I don't know how to remove them but I'm sure I can find out how with a google search.

Thanks

[KWKloeber]

muliti meter, volt-ohm-meter

Clamp-ons are a little plus/minus for lower amps, in-line ammeter is the most accurate (checking one at a time.)

You don't need to remove the GPs, remove the wire and test the resistance (terminal to engine block) or the amp draw of each one separately.

If you need to replace any, do the set - they are cheap enough aftermarket (not westerbeke prices)

Use FTZ brand terminals on your new harness.

[mainesail]

And I don't need the relay any more I guess since I have #10 yellow wire for starter.

Colors matter and a yellow wire signifies DC negative. What you should have is a yellow wire with a red tracer.

[KWKloeber]

Chris
per the ABYC coding that Rod caught I'm unsure if I mentioned b4 to use a permanent red marker to run a stripe down the S Wire  (fancy CD spiral not needed.)
You can also clear heat shrink tubing at each end so the stripe stays put, and/or put a label on it and clear HST. Obviously it's the gold standard to take the time to label/HST them all.
You may have discovered (or not) that 10 ga ignition wire is about impossible to find except by special bulk order. 14 is readily avail but not 10.

Also there's other options but I like this stuff cuz it's very slippery when pulling the new assembly:
http://amazon.com/Expandable-Braided-Sleeving-Polyester-Retardant/dp/B01ETWAW70
Need to melt and zip-tie the ends otherwise they'll badly ravel.

Did you locate a tinned 10 gauge atc fuse holder for the power - if not I'll send you one.

The S wire goes onto what I call the (heat vibrate stretch corrode and) quick-fall-off terminal. I have a couple different fixes for that if interested, but ybyc on how you handle that circuit.

Will you run an extra (#16 brown) wire for a future hi temp switch?
I ran a #16 dkblue for my belt/suspenders oil pressure gauge. Can't ever have too many spare conductors when running new cables . I even ran one to add a sw to temporarily silence the depth alarm (gauge isn't mounted @ the helm.)

[mainesail]

You may have discovered (or not) that 10 ga ignition wire is about impossible to find except by special bulk order. 14 is readily avail but not 10.

I have a spool of 10GA yellow w/red stripe here (if I can find it shop is a disaster zone). If anyone needs some just let me know...

[ChrisW]

Just looking over this subject again and noticed the last reply I made over a week ago is not showing up.  Not sure why.

I did use a permanent marker to put a red streak on the yellow wire and did find an inline fuse holder.  I did the rewiring and everything seems to be working OK. The engine starts, gauges work, and the alternator works.

But, I haven't fused the battery wire yet because I am still getting 30 amps for preheat.  I did not check each glow plug individually because I ran out of time but I did remove one glow plug and I got 20 amps.  The one I removed was the one furthest from where the wire enters the set.  Now it is possible that one of the remaining glow plugs is using 6 amps and the other one is 14, but to me it looks like they are all probably using 10 amps each.  Maybe the glow plugs aren't the original. I am going to check each glow plug individually to be sure, but it looks like I need to do one of the following A) get new lower amp glow plugs, B) get a bigger fuse, or C) install a solenoid for the glow plugs.