Question about 1984 Ford F 250

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Vacuum pump wiring

I am hooking up a brake vacuum pump I got out of a 84 f250 w/diesel. To use for something totally different from it's OEM designation. There are three wires, two red and one black.I need to know what wires go where (ie. red to positive) to make it work. Your help will be much appreciated.

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  • Anonymous Mar 27, 2014

    When car is running the black wire on the positive side of the battery gets very hot there are three wires on the positive side two red one black



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I have 84 & 85 Ford F250 4X4 w/ 6.9 diesel and they use a belt driven vacuum mounted below the alternator driven by a short belt from the alternator.

Have never seen an OEM electric vacuum pump on any Ford F250 w/ 6.9 diesel and early 7.3 non powerstroke.

This must be an after market unit, so look for marking or ID on it to find who made it.

Best guess on wiring, unit may be 2 speed, with black being common or ground and red for power.


Posted on Jul 12, 2008


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