Perkins 4.108 Rebuild Now No Instruments ?

[Sailingdiver]

Hello all,

I just had my Perkins 4.108 rebuilt. The engine isn't even broken in yet. I can't figure out why my instruments aren't working properly. I have a normal instrument panel with tach, water temp, amps, and oil pressure. I have an engine alarm(low oil pressure, I think) I do not seem to have enough sending units to run all these instruments.

Can anyone tell me how many sending units there are? Are any of them dual sensors? I'm really at a loss here. Have tried almost everything I can think of.

Thanks!

[S/V Antares]

Sounds like a ground issue. Instruments are simple. 3 basic connections (forget the lights for now)

Positive
Negative
Sender (S or G)

Many of the perkins panels had VDO instruments so the Sender connection on the gauge may be marked "G" which is "Geber" or giver in German. This often confuses folks.

Check to see if the gauges are getting power. Make sure there is a ground to the engine or to a ground buss bar. The engine may not be part of trhe ground system if it is a euro boat.

The oil pressure sender will be about 1.5 inches in diameter and somewhere in the oil system near the oil filter. The temp sender is in the head (top) near the Thermoastat and will be a small brass unit Hex (Where you put the wrench)with one or two connectors. If it is a VDO temp sender it will have part numbers and max temp (Deg "C") stamped on trhe hex flats (Where you put the wernch).

If the senders have two connectors you likely have an ungrounded system where the ground does not go through the engine. Or you may have sender /warning light combo senders.

Look at the top of the oil sender. It may have a "G" (Sender) and a "WK" (Warning contact) that turns on a light at low pressure.

Do you know what gauges you have in the panel? If VDO they will have the Perkins logo and a small "VDO" under it.

[brutb]

Need to know which instruments are not working, are your instruments electric? How are the ground wires from engine to panel? I am sure with a little info someone can point you in the right direction.... Darn. you seen someone has info. I was just a little slow in typing....

[Sailingdiver]

The instrument panel says Mastry engine center. The tach says Motorola but none of the other gauges have brands. What is VDO?

[Sailingdiver]

I can't find a place/sender for water temp.

[S/V Antares]

Sailingdiver, VDO is a manufactuer of instrumentation and other precision products for the automotive and industrial industry. The supply/ supplied many of the Disesel engine companies (Cummins, Cat, Deere, MAN, Deutz and many others) with gauges or complete panels.

The also supply instrumentation to many automobile companies like Mercedes, Audi, VW and more,

It appears your panel was provided by Mastery Marine of St Petersberg Fl. They may have been the Perkins Distributor for Fl when your boat was built.

The Motorola tach was very common and gets it's signal from the Alternator. The gauges are likely Datcon or Teleflex.

Somewhere on the head (Front or back) just ahead or behind the valvecover is an orafice for a sender. normally 1/4 or 1/2 NPT

[Hannah on 'Rita T']

When we installed a high output alternator on our Perkins 4-236, it screwed up our amp meter. The power for all the other gauges came off the amp meter, so nothing worked. Once we took the amp meter off line and moved the hot wire to one of the other gauges we were back in business.

[forsailbyowner]

My water temp sender is on the back of the head on exhaust manifold side. Oil pressure is near dipstick, there's another water temp sender on the bottom side of the header tank. I put a warning alarm in that one. I've replaced all the guages and senders over the years. No panel here they're mounted into the pedestal. The engine I have is a lowline 4.108