NO POWER TO E/L & A/C SOLENOIDS

[ROBERT MITCHELL]

Good morning all! I drive an 88 carby 5 speed, I havent posted in a while but her is my problem, im trying to get my throttle kicker to work with my ac so it will idle good enough to keep it running. I dont want to just idle it up high so then when the ac is off i have a really high idle. So thats why i would like for the trottle kicker to work. I have searched the site for info and i have found plenty, from vacuum routing to electrical schematics. So i know the vac lines are correct but it seems to me that the solenoids are not getting any power to them and they do work, because i put jumper wires to them and made the kicker work by touching the jumper wires to the battery. The electrical schematic show the wires from the solenoids going straight back to the ECU. So would that mean that there may possibly be a problem with it?

[tooldude]

With the carby, chances are you have old vacuum diaphrams everywhere, so I would suggest you check that the servo diaphram can actually hold vacuum. If it does, check that vacuum is available to the E/L & A/C solenoids (input) when the AC & the headlights + blower motor are on. If it is, check for vacuum on the output side of the solenoids to the servo (and AT the servo). If vacuum is available, check that voltage is actually at the solenoid terminals on the same demand. Of course, you could check these in any order (and the vacuum hoses themselves).

[ROBERT MITCHELL]

Tool, yes the diaphram holds vacuum and the solenoids have vacuum (input and output) but no i have no voltage to the terminals on the solenoids. The hoses are all in goo condition also. So where would you suggest i go from here?

[zoe60]

The way the solenoids work IIRC, is that they have a constant 12 volts on one of the wires on the plug. The other side is grounded when they are off. Sounds backwards, I know. The way the ECU controls them is by removing the ground, which lets vacuum through the appropriate solenoid and engaging the throttle kicker. If you can't get it working you could find a normally closed 12 volt relay and hook one contact to ground, and the other to the ground side of the solenoid, disconnecting the original wire. Connect the coil to the wire that goes to the air conditioner compressor clutch.
i bet the ecu is not switching because if the 12 volts went away you would have high idle all the time. Good luck!

[ROBERT MITCHELL]

Thanks zoe60 i actually thought about trying that but i wasnt sure if there was a way to bypass the ECU. I would like to find out why the ECU isnt switching and fix it the right way because i think there are some other underlying issues as well. I use to recall when i went to turn the car on i would here the slow cut fuel solenoid clicking on the carb for a few seconds, now it dosent, my CEL will not come on either. It does the bulb ck but i tried unpluging the o2 sensor while it was running and it didnt come so then i tried unpluging the coolant temp sensor and it still didnt come on. So if i cant figure it out i guess i will give the 12volt relay idea you suggested a try. Thanks again!

[ROBERT MITCHELL]

zoe60 i went with your ideal of using the 12v relay and it works like a charm. When i turn on the a/c it idles up as it is suppose to and not down and almost cut off. So thanks again for the ideal

[zoe60]

Cool! Glad it worked for you.