Spider wire harnes question

[powerwagontim]

It seems there are various spider harnesses available. What is correct for an M37? I also seem to recall folks using spiders with more legs than needed, and using the extras to power extra circuits? any comments or insights appreciated.
Tim

[Glenn]

If you have a voltmeter you need 5, one for power in and 4 for power out including to the voltmeter.

[cuz]

The #27 instrument cluster wiring spiders came in several forms. Early M37 used the 4 leg Douglas connector. M37's with Packard rubber connectors used the later 4 or 5 leg depending on weather it still had the amp meter or used the volt meter.


Later 5 leg Packard with rubber connectors.


Early Douglas 5 leg used when you need the power to the forth instrument.

[vtdeucedriver]

It seems there are various spider harnesses available. What is correct for an M37? I also seem to recall folks using spiders with more legs than needed, and using the extras to power extra circuits? any comments or insights appreciated.anTim

Tim,
If you find and use a Canadian M-37 harness, their trucks had a couple of extra features and they have come in handy for extra power feeds for our uses.