schematic for alarms on 88 MK1

[boblin]

Just finished rewiring of engine harness and somewhere along the line I got the alarm wires connected wrong. Is there a good schematic of how these are to be hooked up? Red wire from alarm was not moved and is hooked to 12V + where do the grounds hook up? I've gone in to the archives but could not find a clear picture of the alarms.

As usual thanks so much for this forum.

Bob

[Stu Jackson]

Bob,

Try this:

http://www.c34.org/wiki/index.php?title=Engine_Harness_Upgrade

This also has wiring diagrams:

Alternator Regulator Wiring Diagrams - all three http://c34.org/bbs/index.php/topic,4548.0.html

[KWKloeber]

Which engine?

Schematics can  vary by engine.

[boblin]

Universal 25XP

Thanks

[Stu Jackson]

Bob, the links I provided are for the M25 & M25XP.

Also look in the C34 tech wiki for more, there are detailed wiring diagrams posted in the manuals section IIRC.

Universal M25xpb, M35b Operators manual part 1 part 2  (NO direct link)

From the manuals tech wiki page, part 2, page 3 of 26, among others.  There are a number of wiring diagrams in that Part 2 PDF file.

This may NOT apply to you, but read it anyway and then also read Reply #55 on that topic, too, for a discussion of those very wiring diagrams, just so you're fully informed.

http://c34.org/bbs/index.php/topic,3347.msg21085.html#msg21085

The PURPOSE of me linking to this is for you to fully understand the wiring diagrams.  The issue discussed has to do with another problem, not alarms.  But please know that the wiring diagrams are not always "gospel" and can be incorrect and unless you're an electrical engineer you may not find the inconsistencies.  I did, and pointed them out.  Shouldn't be an issue for your problem.

Good luck.

[KWKloeber]

Universal 25XP

Thanks

What's the problem/going on with your alarm?

Note that this is for an OEM M-25, and who knows what a PO may have done.  Also the M-25 may have had the mod to add a temp switch in addition to the temp gauge sender - early M-25 engines didn't have the switch, but I don't know whether the switch was already OEM or still an add-on on the first C-34 M-25s.

OEM M-25 had two "sensors - low oil pressure, which is wired to the oil pressure switch.  Originally the switch screwed into a small, machined, manifold block above the tranny, with a hose leading to the oil port on the engine block (above the starter -- a real PITA to get at.) Later the manifold block was eliminated and the switch moved to the engine block oil port.  That's a 16 AWG blue wire.  Low oil pressure closes the switch and grounds the wire to sound the alarm.

IF YOU HAVE ONE (original M-25s didn't) the high-temp switch is on the STB side of the thermostat cap and has a rectangular, plastic, slide-on with the terminal inside connector (a Packard-56 terminal.)   That is a true temp switch and closes about 200F, grounds the wire to sound the alarm.

The temp (gauge) sender is on the FRONT of the thermostat cap and was typically a 16 AWG brown or tan wire.

However oil/temp alarm itself is more complicated.   The oil is easy - no pressure, switch closed, alarm wire grounds out, alarm sounds.
OEM, temp was different - the front sender is for the gauge, not a switch for the alarm -  Seaward had a circuit board behind the panel that sounded the alarm by "reading" the temp sender.  So there's no switch per-se.  The circuit board was actually the switch that grounded the temp alarm.  Those boards go bad, and are no longer available.

Does that help?

[Noah]

This MAY be relevant...?
http://www.catalinadirect.com/index.cfm/feature/73/z2644--z2855-instrument-panel-wiring-diagram.cfm

[KWKloeber]

Mea culpa.  You did say XP.  Duh. 
Then you should have the temp sw I described on the side of the thermostat cap.  That is typically  a brown or tan or white wire. 

[Stu Jackson]

This MAY be relevant...?
http://www.catalinadirect.com/index.cfm/feature/73/z2644--z2855-instrument-panel-wiring-diagram.cfm

Nice one, Noah.  I'll add it to the engine wiki.