98 Sahara not starting

[warthog]

Hi all, my first post and I'm looking for some wiring drawings to help me diagnose electrical issue and starting my 98 Sahara. First off, a year or so ago when I tried to start the Sahara I turned the ignition switch and nothing happened. Thought it was the batteries went out and checked things and all seemed well. Went back and tried to start it again and it wouldn't do it. A few days later I went back and tried to start the Sahara again and this time everything worked as normal. I scratch my head over that one because I haven't done anything to the chassis batteries to justify the ability to start it. This year I'm trying to move this motorhome and I went to try to start it. Same thing nothing would happen. Check the batteries and found that they were dead and needed to be replaced. I remove the old batteries and installed two new 8D agms. Cleaned all the terminals connections and re hooked up the numerous wires to the battery. I tried to start the motorhome and I would get no indication at all on the dash or the ignition switch that it was getting power or that it would start. I then thought about the switch on the dash that would jump her the house batteries and chassis batteries together. Just for fun I pushed the combiner switch and turn the ignition switch on and all my lights came on and the motorhome would start. I I released the combiner rocker switch and the motorhome would continue to run. Although the voltage gauge was normal when I had the combiner switch on. And as soon as I released it the voltage gauge went extremely high. I cut the motorhome off at that time. I'm trying to find some details for the driver side fuse and relay box outside the motorhome to try to find out if power is going to the right place. If anyone has any detailed information on the driver side electrical panel as to what those items are I would appreciate it. Trying to track down all the different connections going back to the motor is a little challenging without wiring details. Very well could be a grounding issue. Just not exactly sure where to start.

[CactusTwo]

Ok! what you got? I assume a 3126 maybe a B. (40 pin maybe 70 pin) How about a picture of your batteries showing all wires, what is high voltage....real numbers are essential, 13.7 volt or 24 volts?? sounds like a bad wiring reconnect. Cat ECM will NOT start with out of range voltage either low or high. Drivers side fuse panel?? Only panel that connects to start engine is a fuse and relay on small panel in battery box except the ignition wire from the key. Every thing in the front is for other things like lights, wipers, indicators ect. Make note "Not all Safaris look the same" saying the thing on the left towards the bottom means NOTHING to most of us. PICTURES are key. Glad to help with more accurate information. Search here for "Jim Exler electrical" diagrams. He had a 98 Sahara and posted many electrical diagrams

[warthog]

Cactus Two- The electric system is 12v for the caterpillar. When I used the combiner switch to tie house batteries with chassis batteries. The engine would start. All instruments showed as working. The voltage gauge showed around 14 volts until I released the combiner switch and the voltage pegged out to max range 18 v.
I don't think the instrument panel and ignition switch is getting power. That is why I'm looking at the fuse panel on the outside driver side

The wires on the positive side is Transmission, ECM, Service Distribution Panel, Main Battery cable for starter and one odd ball 14 or 16 gauge wire for something. You will see them in the picture. Also there's a 2ga red cable that I added to connect the 2 AGM batteries together.
Normally you would see just two wires on the positive. Heavy duty cable to the starter and 1 distribution for lesser draw.
The other picture is the driver side fuse and relay panel. I think everything from the driver's instrument panel including the ignition switch goes through it. Unfortunately I have no information as to what is there.

[warthog]

Driver side fuse panel outside

IMG_20221215_122840936.jpg (2.44 MiB) Viewed 10763 times

Battery positive

IMG_20221215_123000019.jpg (2.12 MiB) Viewed 10763 times

IMG_20221215_122902508.jpg (2.68 MiB) Viewed 10763 times

[CactusTwo]

driver's side fuses info, top block call FB1, middle one FB2, bottom FB3. FB3 is house circuits and are always from house batteries HOT. top to bottom 1st one power feeds are boost solenoid 5amp ( powers the red dash switch for joining battery banks), second is cargo bay compartment lights 15amp (located inside every compartment door), third is power for main power for entry step 30amp,forth rear camera power (goes through side dash switch to rear camera, possible to inverter switch and front TV to see camera feed, 5th dash fans, 6th mirror heaters ( switch on dash with square box with squiggles) 7th lower driving lights/ fog lights. 8th cigarette lighter socket on side dash. 9th power for both side docking lights ( half way down rig outside at top). Main feed 6g wire with orange 12g wire to 1 of 4 circuit breakers in a row at bottom for power seat power. Look I am going to find the layout of FB's for you online and post it for you, my fingers are sore OK! 2 fingers are sore

[CactusTwo]

some info on starter circuit wiring http://jexler.s3-website-us-east-1.amaz ... ircuit.pdf

[CactusTwo]

Here is Jim's site http://jexler.s3-website-us-east-1.amaz ... elect.html

[warthog]

Thanks Cactus. The starter circuit diagram helps a lot.
Just need to locate the ignition and start relay. I'm thinking my problem is somewhere around the ignition relay.

[1Lotosrggp]

Rule 1, check anything you worked on before you started having problems.
Before we were leaving on a trip I pulled out the battery tray to check everything out. Slide it back in and came back a couple of days later to find it wouldn't start. What I eventually found was I had pulled something apart, probably a relay, connected to the batteries, put it back together and haven't had that problem again.
Rule 2, check grounds.

[cadkns@gmail.com]

I had a similar problem with my 98 Safari Trek engine not cranking. I had just bought it a year ago and it came with a new battery. I would find the battery had 0 volts. I recharged the battery and it load tested good. I looked for an electrical drain problem and found that the leveling system was the culprit. I could not find any shorted solenoids or wiring. I remedied it by installing a battery ground disconnect switch on the chassis battery. I purchased the switch and wire needed from Amazon costing less than $20. I installed it in the driver side front compartment where the generator is located so that it is locked and not easily accessed by a would be thief. To date, I've not had any starting problems. This may be a different issue than you've had but I posted in hopes of helping someone. Thanks for your post and the great discussions!