Voltage required to trigger Fuel Shutoff Relay?
07-05-2010, 09:36 PM
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Voltage required to trigger Fuel Shutoff Relay?
1995 ClubCab, Auto, 160k miles, stock.
Fighting fuel shutoff solenoid troubles. Can lift up on arm and get engine to run. Everything I have read points to the relay if you can lift the arm and it will stay up. Took relay apart and cleaned the contacts inside. Still couldn't get the solenoid to function properly. Broke out the digital volt meter and started checking things. I am getting only about 9 volts out of the brown trigger wire at the relay. Checked it all the way back to the power distribution/fuse/relay box by the battery. Same voltage all the way throughout. I cut the brown wire by the relay and used a jumper wire straight from the battery and the relay closed and the solenoid pulled up.
Are 12 volts required to make the relay function?
Fighting fuel shutoff solenoid troubles. Can lift up on arm and get engine to run. Everything I have read points to the relay if you can lift the arm and it will stay up. Took relay apart and cleaned the contacts inside. Still couldn't get the solenoid to function properly. Broke out the digital volt meter and started checking things. I am getting only about 9 volts out of the brown trigger wire at the relay. Checked it all the way back to the power distribution/fuse/relay box by the battery. Same voltage all the way throughout. I cut the brown wire by the relay and used a jumper wire straight from the battery and the relay closed and the solenoid pulled up.
Are 12 volts required to make the relay function?
07-06-2010, 04:16 PM
#2
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I don't remember if those used dual voltage or dual windings in the solenoid (leaning towards the latter) but there are two stages, one for pull (on start) and one for hold (on run). Once my engine bay cools off a little I'll pull the meter out and check. I don't ever remember hearing of anything on the truck being 9 volts, maybe 5 through the PCM. Corrosion problems anywhere?
07-06-2010, 06:30 PM
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Brown wire voltage that triggers the relay is the same small brown wire on the starter.
It could be loose or corroded under the insulation where you can't see it not allowing enough juice though to trigger the relay.
It could be loose or corroded under the insulation where you can't see it not allowing enough juice though to trigger the relay.
07-08-2010, 09:28 PM
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Updated for future searches...
Start with the easy stuff. The boot on my solenoid was trashed. The outside looked fine from what I could see, but the engine side was all gummy and falling apart. I finally had some help and was able to check the voltage better while someone cranked the engine over. The whole starting system is pulled way down during cranking. I my case it was pulled down from 12.5 to around 9.8 (condition of batteries would play a big part on how far your voltage is pulled down). When I found the voltage at the brown wire to only be around 9 I was sure I had problems elsewhere and stopped looking at the simple stuff.
Start with the easy stuff. The boot on my solenoid was trashed. The outside looked fine from what I could see, but the engine side was all gummy and falling apart. I finally had some help and was able to check the voltage better while someone cranked the engine over. The whole starting system is pulled way down during cranking. I my case it was pulled down from 12.5 to around 9.8 (condition of batteries would play a big part on how far your voltage is pulled down). When I found the voltage at the brown wire to only be around 9 I was sure I had problems elsewhere and stopped looking at the simple stuff.
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