Fuse and gauges question - JeepForum.com
LinkBack Thread Tools
post #1 of 6 Old 08-08-2008, 09:26 AM Thread Starter
Registered User
1987 YJ Wrangler 
Join Date: Jun 2008
Location: Anytown, USA
Posts: 369
Fuse and gauges question

1987 4.2L Laredo, 5spd, A/C

I'm trying to troubleshoot an oil pressure gauge that never moves from zero (oh and the clock doesn't work either). All other gauges work fine.

I've ohmed out the sending unit and it reads about 1 ohm with 0 psi. Sprynet says the ohms should be about 234. And I found an old post here on the forums that says you want about 1 ohm with 0 psi. So I'm not exactly sure what it should be.

I tried disconnecting the wire from the sending unit and turning the key on to see if the gauge pegs to the right but it doesn't move.
I also tried grounding the wire that goes to the sending unit and turning the key on and again it never moves.

I checked my fuses and found that the "clock" fuse was blown (well it was the fuse next to the word "clock") so I put a new one in. Clock still doesn't work and the oil pressure gauge is still a no go. Then I found my "dome" fuse blown. Unfortunately I am out of fuses at this time (will have to go get some more after work). Still need to check a few more but I was in a real hurry.

So my question is: Do all the gauges run through one fuse (like "ACC") or through multiple fuses in the fuse block? From the Haynes manual it looks like they all get their power through one fuse which is the "IGN LPS" fuse but it's hard to tell for sure. I really hope the problem is not on the PCB because I don't want to have to pull the dash out.

Any help is appreciated.


spshultz is offline  
Sponsored Links
post #2 of 6 Old 08-08-2008, 03:33 PM
Registered User
1987 YJ Wrangler 
Join Date: Mar 2005
Location: Rochester, NY
Posts: 19
Not sure if this is the case with your clock but I've bought a couple of clusters for the 87 thru 91 YJ's for various parts. I noticed the printed circuit "wires" leading to both of the clocks were "melted away". Not a lot may be like an inch or two of missing copper foil. Strangely on my current cluster all of the guages work poorly. Gas gauge doesn't all. Oil pressure gauge drops when I turn on the headlights. I have smack the temperature gauge sometimes to get it to read. The clock however works great!
NYScrambler is offline  
post #3 of 6 Old 08-08-2008, 06:18 PM
Registered User
Burnerman's Avatar
1996 ZJ 
Join Date: Oct 2006
Location: Vernon, NJ
Posts: 4,758
Replace the "dome" fuse. IIRC that sends the 12v to the clock. If you remove the dash plastic overlay around the gauges and htr controls, you'll be able to easily remove the gauge cluster and check the ribbon connector. It's a cheesy setup and you'll probably find corrosion at the least or burnt up ribbons at the worst. Mine has a piece of wire jumping the burnt up feed to my clock. It keeps perfect time. I have the schmatic on the PC if anyone needs it.
I'll just post it:
Attached Thumbnails
temp1.gif   temp2.gif  

96 ZJ.
05' Grand Cherokee Limited, 2"OME lift
Burnerman is offline  
post #4 of 6 Old 08-08-2008, 06:22 PM
Mean Max
Don't poke the bear
Mean Max's Avatar
1991 YJ Wrangler 
Join Date: Jul 2007
Location: Stuart, Florida
Posts: 13,734
That's a sweet schematic! I don't need it for myself right now, but it'll be good to have later if I do!

I hope it helps the OP.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Originally Posted by UltimatE View Post
Max has a picture of every Jeep part ever made.
Originally Posted by Benderff View Post
No one here knows what they are talking about. You should try Pirate 4x4 they will be happy to help you.

There is no situation that cannot be improved with a small but well-placed explosive.
Mean Max is offline  
post #5 of 6 Old 08-09-2008, 04:50 AM
Registered User
1988 YJ Wrangler 
Join Date: Jun 2008
Location: W-PA
Posts: 101
That's a keeper! Nice job - Thanks

1988 YJ, 2.5 4cyl TBI, 5 Speed, 4WD, 31's.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
, Herculined. Wrenchin', scrapin', learnin', paintin', enjoy'n! - The "Work in Progress" …continues into '11! (althought she's been on the road since '08! Enjoy it Dad!)
AtzMaBoy is offline  
post #6 of 6 Old 08-09-2008, 04:09 PM Thread Starter
Registered User
1987 YJ Wrangler 
Join Date: Jun 2008
Location: Anytown, USA
Posts: 369
"Dome" fuse it was!! Thank you! The clock now works.

However, the Oil Pressure gauge is still not working. I'm going to order a new sending unit first to see if that has any effect. It looks like the rusty original one is still on it so I'm sure if it was good it won't be for long. Then if the oil pressure still doesn't move then it's dash time. I may try using a mechanical oil pres gauge just to see if I have any (I'm sure I do).
spshultz is offline  

Quick Reply

Register Now

In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page

Similar Threads
Thread Thread Starter Jeep Forums Replies Last Post
Customish Electrical Gauge's Project (replace my 88 gauges with 95 gauges) kgillette YJ Wrangler Technical Forum 15 08-12-2009 08:51 AM
95 YJ Gauges And Blown Fuse Je4x4ep YJ Wrangler Technical Forum 1 07-09-2009 08:24 PM
Which Fuse is related to the dash gauges and radio??? gotsquat_ TJ Wrangler Technical Forum 1 12-13-2007 10:17 AM
Fuse Box Question (Not Fuse 4) tj99 TJ Wrangler Technical Forum 1 10-08-2007 10:57 AM
Which fuse is for the gauges and odometer? chaznad TJ Wrangler Technical Forum 3 09-09-2006 10:15 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome