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Diagnose With Me

716 views 4 replies 3 participants last post by  OldSchoolNoe 
#1 ·
Hello all using a relay circuit tester to find a bad wire or bad ground. It is Cal-Van Tools 76. Simple tester the tool shows 2 lights, green = connected to battery and red = connection to ground. It tests battery to relay wiring (30) relay to switch (86) and relay to component (85)

Currently seeing what these lights tell me about the wires, what do you see? Van has crank no start condition. Fuel pump 60 psi, no blown fuses all relays passed a relay tester test.

Simple right? Here it is testing the fuel pump circuitry
 

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#2 ·
I am not familiar with that specific tool, but it appears to be able to test the circuit of a common Bosch style relay, and manually energize that relay circuit.
Wire #30 is power from fuse block, which will be switched to the load ( Pin #87), when the relay coil ( Pins #85 and #86) are energized.

If the circuit works as it should with the tool, and the relay tests OK, then the only logical result is that the control circuit for the relay is not present to operate the relay.
You will need to trace back up the control wiring to see where the necessary signal is ( should be) coming from.
Also, many of the relays are identical ( look closely at the markings and pin configuration to be sure) . You can easily swap identical relays to test for a possible bad one.
Rod J
Issaquah, WA
 
#4 ·
OEM Tools and ATD Tools make the same tool, just a different brand gets stamped on it.

"There should be at least one red, and one green light illuminated, when testing any given circuit. Both the red and green light should not illuminate on any given circuit, as this indicates a short in the circuitry."

Oh so now those pictures are starting to make sense

Fuel Pump Relay - Both lights on for 30 and 86 = There's a short between the relay and the fuel pump switch (I'm assuming it would be ignition key)

Starter Enable Relay - Both lights on for 86 = There's a short between the relay and the starter switch (I'm assuming it would be the ignition key when turned)

IGN Relay - Both Lights on for 85 = There's a short between the relay and component. So what's IGN relay going to? The Ignition control module?

Not shown is the A/C Enable relay(5pin) . Tool says (red 30) (green and red 86) (green 85). There's a short on 86, relay to a/c switch?

Not shown is the A/C Relay (4pin) - (green red 30) (green 86) (green [dim red] 85). There's a short on 30 battery to relay.

I don't care for A/C so I can just leave those relays disconnected. I learned that the wiring to the starter switch is somewhat funky. Anyone agree with me? The ignition key is not the original, previous owner installed a different ignition lock cylinder. I do not know what the "IGN Relay" powers but I'm assuming it is the ICM.
 
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