electrical help! ac pressure switch
07-24-2014, 01:54 PM
#31
Senior Member
Thread Starter
One thing you might be able to use (instead of blowing fuses) is get a voltmeter (do NOT use Ohms/continuity - DC Voltage only), put the positive on the fuse feed side in the socket, put the negative on the circuit feed side. If you're reading +12V you likely have a dead short (completed circuit) to ground. This might save you from blowing fuses as well while you try and trace what it is... You should read 0V (open circuit). If you put the probes backwards, it'll just read -12V so no big deal.
Last edited by IceFishinFool; 07-24-2014 at 02:00 PM.
07-24-2014, 10:42 PM
#32
Senior Member
That'll be your best way to start narrowing without blowing fuses. The other thing I sent you (short detector), you can actually follow the wires using magnetism. Once the magnetism stops (meter shows nothing), you've passed the short. If it's a crunched wire or similar (and it may be), you may have to go to that option to make your trace much less time consuming.
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IceFishinFool (07-24-2014)
07-25-2014, 12:18 AM
#33
Wires could have melted together there if it passes within a couple inches of the manifold or even touched it in that area where the cover is off the loom ? That would be a short for sure. Those wires melting together can sometimes be a slow process with on going symptoms for a few cycles that's for sure. Usually it is a shorted relay or semi conductor though. U just never know until you cut it out of the circuit. I have had to peal thru wire harnesses before and once found a crimp of several wires that had corroded the copper and created to much resistance in those circuits.
Last edited by papa tiger; 07-25-2014 at 12:22 AM.
07-25-2014, 01:05 AM
#34
Senior Member
x2, agree with that! Also love your UPS truck comment papa tiger hahaha. You're right though, you never know what will happen. I can't recall if the harness is near there but even if a clip breaks and the wiring harness ends up close to the manifold it can melt. Hopefully it won't be too hard to trace down 
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