The Snakes Alive CMP Wiring Project

[Hanno Spoelstra]

Originally Posted by Jacques Reed

Just looking at your picture there should be a wire, 30A, a jump from the oil pressure gauge brass bus to the Temperature gauge brass bus to supply current to the Battery and Oil Pressure gauges when the ignition switch is thrown.
There should be wire, 30, from the ignition switch to the Temperature gauge brass bus to supply current to the Temperature and Fuel gauges and then to the other gauges via 30A.

The wire into the Battery indicator is my concern. If it shows voltage only when the ignition switch is thrown then it is wire 30 and can be connected to the brass bus at any gauge to supply them with current. Diagram shows the Temp gauge but any brass bus is the same electrically.

If for some reason that wire into the Battery indicator shows voltage continuously it could be coming directly from the Battery via the regulator and therefore your wiring is setup for an ammeter. If that is the case it could cause a serious problem to the wiring and gauges if the Battery indicator is sent to earth. A quick check will determine if that wire is "hot" only when the ignition switch is on and therefore set up for a Battery indicator.

I have found with numerous owners over the years and many jury rigged wires on these vehicles it is best to check and double check. My first truck had many disconnected wires and even house wiring used in some places!

Hello Jacques, thanks for your guidance.

Currently the dash on my F15A is wired as follows:

• Live feed from ignition switch to BATT, strip connector to OIL pressure, then a wire runs (hence the double wire in the connector) from BATT to TEMP with a strip connector to FUEL.

I checked and the instruments are "hot" only when the ignition switch is in the on position. I have temporarily grounded the BATT meter (see the blue connector) and when the engine is running it slowly creeps up. Have yet to take it for a test drive to see if it is in the green at driving speeds.

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Indeed previous owners have fiddled with the wiring, hence my actions now to go through it, understand and correct it. It does not help the original covering has faded to a level where the colours are very hard to discern. Hence a rewire is scheduled for this winter.

For the upcoming event this weekend I have proper working indicators again, over the years they became dimmer and dimmer, with the old mechanical flasher relay, dash indicator light and bad connections robbing away 1.5 V from the 6 V available. With the connections cleaned up, dash indicator light omitted and an electronic flasher relay I now have the full 6 V supply to the indicator lights.

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