ragged claws

Tried this on the General forum without much response. Probably because this is a pretty stupid question. How do I ground the green wire to my Low Coolant light sensor without pulling the sensor from the radiator tank and causing a coolant leak? FSM says to ground wire to check sensor but doesn't say how to do it. My car is an '89 coupe.

Thanks, Kim

LarryK 87

just make up a quick cheap jumper, i have a set i keep in the tool box, alligator clips each end, one about 18" long, and one about 3' long, total cost, $4.00 Radio shack

ragged claws

Here's the stupid question part: what do I jump from and what do I jump to? Do I have to shave some insulation off of the wire before the sensor to attach the alligator clip? Can I clip the other end of the jumper to any steel part in the engine bay?
Sorry to be so obtuse.

Kim

engle1147

Use a sharp wire probe to push through the wire insulation into the wire...ground the other end of the probe to the engine block. Or you can cut the wire's insulation back and tape it up when your done.

engle1147

I'm not at home and do not have access to my FSM.....maybe one of the other CF members can help you out with which wire you need. It would be a good idea to pick up a Factory Service Manual (new reprints retail ~ $130) for your year car if you plan on hanging on to it. I saw a used '89 for FSM sale in the C4 parts section you may be interested in...http://forums.corvetteforum.com/c4-p...ce-manual.html

engle1147

Amazingly the book for sale in the C4 section,that I just mentioned, is turned to the exact page you need.....book shows the ground wire for the relay to be green with white tracer (if I read it right). Must be your lucky day!

LarryK 87

cant say for a fact the 89 is the same as my 87, But the level sensor is a simple single blade plug, on mine it is on the pass side of rad, nearer the top, easily unplugged, then ( again my solution) using a wire with alligator clips at each end, i connect one end to any ground point ie frame etc, then to the single wire that was connected to the low level sensor. When i purch. mine, the level sesnsor wire had been shunted to ground, and assuming the sensor is bad i bought a new one, looks like a simple plug in to rad deal.

mseven

I prefer using methods of placing a wire in the terminal and plugging it back together, or jumping w/clips (like above mentioned), even when a vohm meter is being used for testing.

ragged claws

Thanks for all the replies guys. LarryK, are you saying that I can pull the plug on the sensor without removing the sensor from the radiator? I can't find a place in my FSM that shows the details of the sensor.

LarryK 87

on mine yes, it is a single blade connecter( wire end is the female end), like those crimp on things, you should even be able to make up a short peice with a male blade to eyelet or ring lug then bolt that to any available ground location, if the remainder of the circuit is ok ( only a bad sensor ) then the light will go out.
temp fix until you get the replacement part. when you get he new item, install it into the rad, disconnect the shunt, and plug the un-altered wire back onto the sensor.
complete and restored to OEM like condition

The sensor uses integrated clips to hold it into the rad.

http://www.ecklers.com/product.asp?p...0&dept_id=1309

ragged claws

Thanks a lot, Larry. That certainly clears things up. I'll order the new sensor today. I assume that to install the new sensor I will need to suck out some coolant to lower the level to below the sensor location. Then it should be just plug and play.

engle1147

There is a drain plug in the lower driver's side area of the radiator.

ragged claws

Thanks for the info about the drain plug but I was hoping that I only have to get the coolant below the sensor before removing it. The cooling system was recently flushed and the coolant in the car now is pretty new. I'd hate to drain the whole radiator if I don't have to.

engle1147

Catch it in several pans/buckets, replace the sensor and pour the coolant back in there.

LarryK 87

besides, i doubt you will loose much more than a 1/2 gallon worst case, not like you need to remove any hoses


The above assumes you will be pulling the car onto a set of ramps which will elevate the front end, remember the top of the radiator is below the top of the motor water jacket.

ragged claws

Gotter done! Turns out I don't have to drain the radiator or even replace the sensor for that matter. I took the connector off and saw that the blade and inside of the connector were oxidized. A small flat jewelers file and some 600 grit sand paper fixed the problem. Hooked the connector up, started the car, and no more Low Coolant light. I wouldn't have known how to take the connector off without all your help. Thanks guys.

Kim

coupeguy2001

Guys! Guys! (slaps forehead)
the low coolant sensor is a atraight stainless steel blade that sticks into the water, That's it!
just a piece of metal, no resistance, nothing. no bimetallic spring, etc. just a metal blade sealed by plastic held in by two fingers.

The WATER grounds the blade by conducting to the block through the water through the block grounds and puts out the light.
The water level gets low, and theblade can't touch the water, and the transistor turns on the light.
Want to check it? pull the single blade connector off the sensor, and the low coolant light comes on. want to put it out? get a paper clip, put it in the connector, touch it to ground.

LarryK 87

nothing fancy about it, hey even the general gets it right every now and then, of course they probobly fired the guy that came up with that, so the new guy could design one that used a minatureized sonar module to determine water depth above the sensor with a compensation module to deal with heat gradiants, and some form of mini-tidal flow acceleration meter to deal with the lateral dynamic fluid motion results from the water pump and from abrupt changes in direction mainly in a right handed direction....

or they could just discontinue using it in cars because the new one was to complex.

engle1147

I see...thanks for the heads up no wonder I never had to replace mine.