Trojan Gauges 1970-1980

[BeaconMarineDon]

From 1970-1980 Trojan used AC Delco gauges. Occasionally, some Trojan F Boats before 1980 (like the F-30 1979-1980) used Datcon gauges.
Problems occur when these rules are not followed. Often, this is the mistake of a marine technician who is unaware of how Delco gauges and senders work together.

A very common mistake deals with Delco gauges and senders. Typically, an owner notices a gauge problem and assumes it's an issue with the sender. The sender is replaced with an off-brand / non-Delco sender -- only to find that the Delco gauge readings are off or the gauge is not working at all.

Here are some of the basics of Delco gauges and senders:

1. You can identify a Delco gauge by it's tin backing. Delco gauges do not have plastic backs.

2. There are two types of Delco gauge - a single station gauge and a dual station gauge.
Delco gauges are are also stamped as 'Single' or 'Dual' on the side (see photo)

3. Each type of Delco gauge has a single sender. For example, Delco fuel gauges must use a Delco fuel sender. The same applies to
engine temperature and oil pressure gauges. Note: A Delco sender will power either a single or a dual gauge system.

4. Trojan used either white needle or orange needle Delco gauges.

At Beacon Marine, we have Delco single and dual gauges. We also have the senders for fuel and engine temperature. We *do not* have any
Delco oil pressure senders. But, *WE DO* have an oil pressure gauge that is a close match to the Delco oil gauge and a matching oil pressure sender.

[JimmyPajama]

Very helpful - I would like to replace my gauges. I know gauges differ by the type of engine and drive. My gauges are plastic backed and green see attached. Do I need to replace the sending units when replacing the gauges?

Thanks Jimmy

boat gauges.jpg (86.63 KiB) Viewed 30077 times

[prowlersfish]

Your gauges will need to match the senders .You may be able to get gauges with the same specs. I don't believe your gauges are the original . Any close ups ? If I zoom in they get blurry

[prowlersfish]

Why are you replacing them ? Any issues

[captainmaniac]

Your gauges will need to match the senders .You may be able to get gauges with the same specs. I don't believe your gauges are the original . Any close ups ? If I zoom in they get blurry

I believe those gauges are original as they match what was originally on my '79 F32. I understood they were 'DetMar' gauges - Detroit Marine - but have never been able to confirm it. I replaced mine with some new Teleflex gauges that were compatible with existing senders.

[Captrichc]

Your gauges will need to match the senders .You may be able to get gauges with the same specs. I don't believe your gauges are the original . Any close ups ? If I zoom in they get blurry

I believe those gauges are original as they match what was originally on my '79 F32. I understood they were 'DetMar' gauges - Detroit Marine - but have never been able to confirm it. I replaced mine with some new Teleflex gauges that were compatible with existing senders.

Where and how did you get the specs for the sending units?

[captainmaniac]

Where and how did you get the specs for the sending units?

It was way too long ago that I don't remember... If I remember correctly there are 2 primary types of senders - one is based on current, the other based on resistance. What I replaced the old gauges with was Teleflex Red International, which worked with whatever senders I had. I had a tach blip out a few years later and replaced them with new Teleflex Amega ones (since Red Internationals were discontinued by that point).

Here is what one of my old (original) gauges looks like

Picture1.jpg (40.71 KiB) Viewed 29998 times

Picture2.jpg (31.32 KiB) Viewed 29998 times

One other consideration as Bob indicated - single vs dual station setups require different senders. If you only have a single station and are adding a new set of controls you would need new sender. If you are dual station right now and are disconnecting one set of gauges, you may need to switch to 'single station' sender. Also make sure you get stuff for inboard engine vs outboard! But if not changing configuration, if you research what what kind of sender the teleflexes need, that's probably what you have.


EDIT
Just took a closer look at the packaging from one of the Red International Water Temp gauges and sticker says 'For Code D Sender' looked. So did a quick search and found this http://gfretwell.com/electrical/teleflex%20senders.pdf From this you can see a Code D sender for dual station is 120ohm at 120f... so you can probably use this to figure out what senders you probably have and then find new gauges compatible with those specs.

[Captrichc]

Where and how did you get the specs for the sending units?

It was way too long ago that I don't remember... If I remember correctly there are 2 primary types of senders - one is based on current, the other based on resistance. What I replaced the old gauges with was Teleflex Red International, which worked with whatever senders I had. I had a tach blip out a few years later and replaced them with new Teleflex Amega ones (since Red Internationals were discontinued by that point).

Here is what one of my old (original) gauges looks like

Picture1.jpg
Picture2.jpg

One other consideration as Bob indicated - single vs dual station setups require different senders. If you only have a single station and are adding a new set of controls you would need new sender. If you are dual station right now and are disconnecting one set of gauges, you may need to switch to 'single station' sender. Also make sure you get stuff for inboard engine vs outboard! But if not changing configuration, if you research what what kind of sender the teleflexes need, that's probably what you have.


EDIT
Just took a closer look at the packaging from one of the Red International Water Temp gauges and sticker says 'For Code D Sender' looked. So did a quick search and found this http://gfretwell.com/electrical/teleflex%20senders.pdf From this you can see a Code D sender for dual station is 120ohm at 120f... so you can probably use this to figure out what senders you probably have and then find new gauges compatible with those specs.

Awesome info. Thankyou so much for all the help.