No fuel in lines or pressure
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Understand that it is only grounded for 2 seconds after ign is turned on, then again after it starts.
I found it tricky to check alone. With my meter on ohms I put one probe in 85 and grounded the other. Then you need to watch the meter while you turn the ign on. It might not be long enough to get an actual reading, but you will see the numbers change. Very likely your problem is elsewhere being that you have no power.
Just for fun and to test your pump you can ground the black from the pump anywhere, anytime.
I found it tricky to check alone. With my meter on ohms I put one probe in 85 and grounded the other. Then you need to watch the meter while you turn the ign on. It might not be long enough to get an actual reading, but you will see the numbers change. Very likely your problem is elsewhere being that you have no power.
Just for fun and to test your pump you can ground the black from the pump anywhere, anytime.
Thread Starter
CF Veteran
Joined: Apr 2013
Posts: 1,153
Likes: 7
From: Rowlett, Texas
Year: 1988
Model: Cherokee
Engine: 4.0 Inline 6
Ok ill trace the orange wire... hopefully it leads to the starter motor relay.
Now quick question, i know the starter motor relay where the battery terminal is and the fusible links all are always hot. Theres the terminal for the fuel pump ballast resistor, is that always with power or only when the key is in ignition?
Now quick question, i know the starter motor relay where the battery terminal is and the fusible links all are always hot. Theres the terminal for the fuel pump ballast resistor, is that always with power or only when the key is in ignition?
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
You might read my post #80. The pump gets power from the start relay only while it's cranking. (It's also a handy place to jump power to the pump)
Senior Member

Joined: Jul 2011
Posts: 560
Likes: 25
From: West Covina, Ca.
Year: 1988
Model: Cherokee
Engine: 4.0
Note from DJ to Batman33165
Fuel Pump Ground Improvement by cruiser54
http://cruiser54.com/?p=249
POST #85
QUOTE from cruiser54’s instructions: Locate the black wire on the HARNESS side of the fuel pump/sender 3 wire connector.
-----------------------------
Post #90 by Batman33165
QUOTE from Batman: I HATE TO RUIN A NEW FUEL PUMP CONNECTOR BY ADDING THE GROUND but okay, I’ll try doing the tip today.
You are talking about adding the ground improvement to your FUEL PUMP HARNESS; not to the Jeeps HARNESS CONNECTOR as per cruiser54 Instructions so that the improved ground will stay with the Jeep if the fuel pump is ever changed out.
Fuel Pump Ground Improvement by cruiser54
http://cruiser54.com/?p=249
POST #85
QUOTE from cruiser54’s instructions: Locate the black wire on the HARNESS side of the fuel pump/sender 3 wire connector.
-----------------------------
Post #90 by Batman33165
QUOTE from Batman: I HATE TO RUIN A NEW FUEL PUMP CONNECTOR BY ADDING THE GROUND but okay, I’ll try doing the tip today.
You are talking about adding the ground improvement to your FUEL PUMP HARNESS; not to the Jeeps HARNESS CONNECTOR as per cruiser54 Instructions so that the improved ground will stay with the Jeep if the fuel pump is ever changed out.
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
??? The tip is to improve the Jeep side of the connector. Myself, in your shoes I'd check the Jeep side ground with the meter first, see if that's a priority right now. Sounds like it IS, if you powered a new pump and it didn't run.
Thread Starter
CF Veteran
Joined: Apr 2013
Posts: 1,153
Likes: 7
From: Rowlett, Texas
Year: 1988
Model: Cherokee
Engine: 4.0 Inline 6
I was not able to do anything this weekend, i do not have power going to the pump.
The only reason i did was because i used that bypass with a 15 fuse in it
The only reason i did was because i used that bypass with a 15 fuse in it
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
There are only three functions, (out of a zillion), that a Renix Jeep needs in order to work on it. Ohms, (with the headphones symbol), and DC volts, under 20 if it gives you a choice. DC volts might have a straight line and a V. (AC volts has a wavy line). You will normally just need DC Volts and Ohms. (CPS can be checked with ACV).
Just set it on ohms and touch the leads. That's all there is to checking resistance, you just put what you are testing between them. (IE the Jeep side black pump ground wire, to bare metal of the body.) If it's more than an ohm or two you need to either find the bad connection or do Cruisers tip.
Just set it on ohms and touch the leads. That's all there is to checking resistance, you just put what you are testing between them. (IE the Jeep side black pump ground wire, to bare metal of the body.) If it's more than an ohm or two you need to either find the bad connection or do Cruisers tip.
Thread Starter
CF Veteran
Joined: Apr 2013
Posts: 1,153
Likes: 7
From: Rowlett, Texas
Year: 1988
Model: Cherokee
Engine: 4.0 Inline 6
I will try to check the volts again today when i get home, and ill give a try to Ohms. (thanks for the headphones symbol) i have it on the multi meter.
Other than that.. i had pictures but someone stole my phone off the jeep as i went inside my apartment to get a couple things...

i came back out to take a few pictures and could not find it so...
Other than that ... lol, i did the tip for the grounding for the fuel pump. Made it look nice, oxgard it, and covered all the wires from the outside debris. I used the test light again and checked power from the starter motor relay battery terminal. Checked the wires that were either green, orange, (1) blue, (1) red. Using the test light i checked the fusible links in 2 locations, one time closes to the battery terminal and the other past the rubber looking capsule.
By the way im still at nothing....
Other than that.. i had pictures but someone stole my phone off the jeep as i went inside my apartment to get a couple things...


i came back out to take a few pictures and could not find it so...Other than that ... lol, i did the tip for the grounding for the fuel pump. Made it look nice, oxgard it, and covered all the wires from the outside debris. I used the test light again and checked power from the starter motor relay battery terminal. Checked the wires that were either green, orange, (1) blue, (1) red. Using the test light i checked the fusible links in 2 locations, one time closes to the battery terminal and the other past the rubber looking capsule.
By the way im still at nothing....
Thread Starter
CF Veteran
Joined: Apr 2013
Posts: 1,153
Likes: 7
From: Rowlett, Texas
Year: 1988
Model: Cherokee
Engine: 4.0 Inline 6
I forgot... i was curious on the ballast resistor that i installed new, apparently that sucker was hot as H...E...double hockey sticks. So i decided to remove the connections and connect them both to the fusible link i made with a 15 amp fuse. Im kind of excited but every time i turned the key into ignition the fuse would pop, did it a couple times to confirm my findings.
I know its nothing to be excited but it is something new, and that sometimes means we are finally going somewhere
I know its nothing to be excited but it is something new, and that sometimes means we are finally going somewhere
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Your meter might have a resistance setting that makes a beep? If you check resistance from that hot wire to ground, you will find there isn't much. My meter beeps so I could go under and jiggle wires and see if it stops. If you can have a friend watch the meter while you trace the wire and jiggle things that could work. I think you found your original problem! (don't fear the meter, it's your friend!)
Last edited by DFlintstone; Mar 28, 2017 at 10:05 AM.
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
OK if that's shorted well enough to pop a 15 amp fuse your fusabke link may have gone. (so you have two issues) My diagram says its Orange (or Green). Meter set on ohms, it's the wire, (past the link), that has continuity to relay socket 30. (guess they might all be Red downstream of the links) It's possible, but a little tricky, to push a pin or needle through insulation to test a wire. Also I suppose you could juice #30 and test disconnected wires/links with your light.
I'd toss the relay that was in it. Even if it seems to work, they are cheap and I wouldn't trust it after handling a short.
I'd toss the relay that was in it. Even if it seems to work, they are cheap and I wouldn't trust it after handling a short.
Last edited by DFlintstone; Mar 28, 2017 at 12:03 PM.
Thread Starter
CF Veteran
Joined: Apr 2013
Posts: 1,153
Likes: 7
From: Rowlett, Texas
Year: 1988
Model: Cherokee
Engine: 4.0 Inline 6
ok so a little update... I still have not done the ohm checking, soon though...
Well i redid the grounds from tip 1 in cruiser because i did one of the grounds in the wrong place ( i put the ground from the firewall to the original spot instead of firewall to the heat shield bolt).
With that i retested everything... no more fuse popping, but does not solve my fuel pump problem. So i did something i learned online, using a test light. I put the test light wire to the positive instead of the negative and touched the relay. more preciously the orange with black strip (85). And nothing lighted up, so somewhere in that line there is power going to it instead of ground. Having the test light in the positive terminal again i touched the orange wire (87) and guess what happened, there was light. So it means there is a ground where it should be power
Well i redid the grounds from tip 1 in cruiser because i did one of the grounds in the wrong place ( i put the ground from the firewall to the original spot instead of firewall to the heat shield bolt).
With that i retested everything... no more fuse popping, but does not solve my fuel pump problem. So i did something i learned online, using a test light. I put the test light wire to the positive instead of the negative and touched the relay. more preciously the orange with black strip (85). And nothing lighted up, so somewhere in that line there is power going to it instead of ground. Having the test light in the positive terminal again i touched the orange wire (87) and guess what happened, there was light. So it means there is a ground where it should be power


