88 Renix 4.0 XJ Various Questions

Hey guys I have a few updates. I am making another thread with a more appropriate title.

Got the Cherokee running well now starts up and runs great. Transmission was not shifting into reverse and it ended up being low fluid and that was easily remedied with more fluid.

There are a few things that I am still slowly working out the kinks too:
1. Fuel Gauge Not working, details below.
2. Cluster back illumination lights not working. Checked the 7.5 amp fuse and that was good. Checked the parking light knob and turned it all directions and nothing. I've been reading around that there is a ground connection hub for various items including the cluster illumination, dome lights, etc. and a second ground wire should be run. Although my dome lights are working for example.
3. Brakes aren't bleeding as well as I would have hoped. Still have a very spongy brake pedal and minimal braking force. What else should I do/check? Also sounds like the rear drums have high/low spots and are dragging. Need to be pulled off and inspected.
4. Blower Motor Diagrams. Trying to get the HVAC system up and running, primarily the heater. Don't think the motor is coming on, looking for diagrams to try and follow.

- Fuel gauge details. It is reading empty with about 8-10 gallons of gas in the tank. I've read that if the ground wire is bad, it'll peg full. Then on the flip side, if the sending unit power wire is bad it'll read empty. I just put in a new fuel pump and sender unit a month ago and it never made a difference. With the original pump/sender unit, it still did not read anything past E either, (I think).

I pulled the gauge cluster and traced the leads from the gauge to where it the pigtail plugs in. I noticed a spot had a broken connection, like a wire was supposed to be in this spot, soldered in.



Maybe that lead where a wire "may go" runs over towards the fuel gauge area.

Thanks everyone.

Snobrdrkid07 said:

3. Brakes aren't bleeding as well as I would have hoped. Still have a very spongy brake pedal and minimal braking force. What else should I do/check? Also sounds like the rear drums have high/low spots and are dragging. Need to be pulled off and inspected.

- Fuel gauge details. It is reading empty with about 8-10 gallons of gas in the tank. I've read that if the ground wire is bad, it'll peg full. Then on the flip side, if the sending unit power wire is bad it'll read empty. I just put in a new fuel pump and sender unit a month ago and it never made a difference. With the original pump/sender unit, it still did not read anything past E either, (I think).

I pulled the gauge cluster and traced the leads from the gauge to where it the pigtail plugs in. I noticed a spot had a broken connection, like a wire was supposed to be in this spot, soldered in.



Maybe that lead where a wire "may go" runs over towards the fuel gauge area.

Thanks everyone.

Click to expand...

Well, guessing by the symbol printed on there, a diode may have been there. Sorry I don't know what mines looks like as it's installed.

Brakes, one thing I thought of is to check that the calipers aren't switched left to right. The bleeder valve should be on the top of the caliper, if it's on the bottom, you'll never get all the air out.

Go to post # 18 in the following link for the instrument panel ground upgrade. Wouldn't hurt to do #1,2,3 and 4 when you get a chance.

http://www.cherokeeforum.com/f51/cruiser54s-mostly-renix-tips-153657/

I don't see where you say there is a broken connection. If you are talking about the two blobs of solder, there is a hole in the board and a component sticks through from the back and gets soldered.

Do clean the connections on the left where it bends down with an eraser and get them cleaned up. That is most likely where your problem was.

Thanks for the replies:

1. The bleeders for the front calipers are on the top, so those are correct. I used a turkey baster to remove old fluid from back part of the reservoir and replaced it with new fluid. I had left the cap off of the fluid reservoir and was a little surprised to see that fluid was shooting everywhere. The front part of the reservoir has a nasty gray color fluid coming out of it too. Still working on the breaking loose the right rear bleeder.

2. Learning fast that Renix can be associated with bad grounds, everywhere. Will check that out and do that upgrade this week. I'll see if that fixed the gas gauge, cluster lights, and anything else. (Would that ground effect the gas gauge from working?) Will make note and time to do the other ground/wire clean ups.

3. The two blobs of solder was what I was referring to, I thought there was supposed to be a wire between them. I'll clean the contacts up, there is a little bit of corrosion on them from what I can remember and see from the picture.

Snobrdrkid07 said:

Thanks for the replies:

3. The two blobs of solder was what I was referring to, I thought there was supposed to be a wire between them. I'll clean the contacts up, there is a little bit of corrosion on them from what I can remember and see from the picture.

Click to expand...

I have mine apart and checked it ('90 Renix). It looks identical to yours with no wire or diode installed between those two solder points (but it also has the diode pic in the same place). All of my gauges work perfectly so your problem is somewhere else.

old_man said:

I don't see where you say there is a broken connection. If you are talking about the two blobs of solder, there is a hole in the board and a component sticks through from the back and gets soldered.

Do clean the connections on the left where it bends down with an eraser and get them cleaned up. That is most likely where your problem was.

Click to expand...

Like Oldman said the first thing to check is the contact strip. It gets coated in oxidation, the voltage coming through there to the gas tank sender is tiny. There is a TSB (technical service bulletin) about cleaning the contact strip. I use an ink (coarse) eraser and spray out the female end with contact cleaner, plug and unplug it a few times.

The higher the resistance between the gauge and the sender (the sender is 0 0hms, plus or minus a few, tank empty and 88 Ohms tank full), the higher the fuel gauge is going to read. At least three connectors between the dash and the fuel pump and 2-3 between the pump and the ground, any of which could be adding resistance.

In case I'm wrong, you will likely be able to figure it out pretty quick, unplug the fuel pump connector with the key on and see if the gauge goes all the way up. I think on the YJ (or maybe it is Dodge) it is the opposite and I might be confusing the two.

Carefully pry open the rubber boots on the end of your rear brake cylinders and see if brake fluid seeps out. If the pistons are leaking you may never get a good bleed.

Carefully pry the front of the rubber and cover/boot from the wheel brake cylinder and you can get it back on there without having to remove anything. If it pops off all the way or you try to open the rear of the end boot it is pain to get back on again.

If brake fluid has leaked onto the shoes (they swell and get soft) you'll get that swish, swish, swish sound as they turn. Or the drums just may be full of rust and dirt.

I wash my brake parts with dishwashing soap (suds) with really hot water, then rinse. I use a bottle brush to get into the tight spots. Then sand the shoes and drums with 100 grit sand paper. Sand sideways (45 degrees) to the direction of rotation, then reverse and do it again. What you want when you get done is kind of a cross hatch or X pattern. I wash the salt, old brake fluid, dirt and whatever out of my rear brakes twice a year. Sanding them (knocking off the high spots) once a year lets them reseat and seems to keep them wearing equally over the years and helps avoid channels worn into the drums. Don't get carried away with the sanding, just sand off the highest spots and remove the glaze, don't try to get them perfect.

While your in there check the star wheels on the adjusters to make sure they aren't frozen. Improperly adjusted rears (automatic adjuster isn't working right) can make the pedal feel low or spongy also

I did see a little bit of oxidation on the strips, I'll clean those off and report back. I did a cluster swap a week or two ago but I don't think the connection spots are different, from what I have read.

I did notice that I get a grinding sound from the rear that is speed dependent. I am 99% sure it is the rear brakes. Going to have to pull the drums and get a visual of what is going on in there.

Unplugged the fuel pump and the gauge went past Full. Plugged it back in and it went down to E. So an open circuit with "infinite" resistance makes it go Full, then a resistance of basically 0, closed circuit makes it read E. So to me that means that is has a good connection? Wonder if the float is out of whack or I messed it up when installing it. I put an Airtex Pump/Sender in there, and from reading around, I regret this decision.

Fuel gauge.

0 ohms empty.
44 ohms 1/2.
88 ohms full.

cruiser54 said:

Fuel gauge.

0 ohms empty.
44 ohms 1/2.
88 ohms full.

Click to expand...

Right, but, it is reads empty all the time. So that means to me is that it has a "good" connection? If there is very little resistance, I don't see how there could be a bad wire/ground somewhere. Sorry if I don't follow.

What's the ohms reading from the sender to ground?