starter problem

96 xj 4.0 automatic

I pulled into Taco Bell and killed it. When I tried to start again, it would not crank. I'm still getting power and even had a friend try to jump me. Full power to the dash, headlights, etc. Starter won't even click. I do hear a click from the relay when someone else tries to start it.

I pulled the NSS, opened it and cleaned it, and replaced it. I checked all the connections, batt. cables, and fuses.

I pulled the starter and went to the 24 hour Vatozone. When they tested it, came back positive. Do these tests also check the solenoid??

I didn't try the gentle tapping with a BFH, nor did I try to jump it with a screwdriver across the two terminals as I just read about these tricks now.

Any ideas??

will

The solenoid is part of the starter, so it will be tested as a part of the thing. The solenoid is responsible for both engaging the starter drive to the flywheel ring gear, and powering up the starter windings - and the solenoid is designed to power up the windings AFTER the drive is engaged.

If the starter kicked out and started spinning, you're golden.

Now, I'm looking at my 1997FSM (the 1994 FSM I've got is for OBD-I, and the 1996-up is OBD-II) and I'm seeing a start motor relay in the PDC - has that been checked? Looking at the pinout, it would seem to be a regular Bosch/Hella relay, and you should have a few of those on hand anyhow. Test by substitution - you can probably find one locally for less than $10, and you can mail order Bosch relays for down around $2-4 with a little digging (check out Parts Express - www.partsexpress.com.)

The start relay is engaged by the ignition keyswitch (about 80-100mA,) which then supplies current to the start solenoid (10-12A.) The start solenoid supplies full current to the starter motor windings (about 160-180A) to crank the engine. The start relay is really the weakest link in the chain - I went through four in my 87 one summer (ChryCo OEMR's) before I rewired it to take a Bosch - the ChryCo's were about $40 a shot, and I buy Bosch relays by the dozen for maintenance and various electrical mods. Keep a few spares in with your spare fuzes and light bulbs - you do have a box of spare fuzes and light bulbs, don't you?

5-90

How can I test the relay??

BTW, thanks for the timely response Jon. I was about to blame my "5-90" cables. jk

It's easier to test the relay by substitution than by any other method. You can test the relay using a 9V battery and a meter or a continuity checker - the schematic for the relay internals is usually printed/stamped into the side of the thing. The "break" circuit is rarely used, so you'll want to make sure that you do NOT have continuity on the NO (Normally Open) terminals, and that you DO have continuity (with minimal to no resistance) when the coil is energised by the battery. A good fresh 9V battery will trip nearly almost any 12VDC relay - except serious specialty jobs.

If the relay checks good, make sure all connections are clean, and that the connections under the relay didn't somehow corrode (I'm going to go out on a limb and presume you've already done this - this is more for posterity than anything else.)

5-90

I'll try putting the starter back in the morning and pick up a new relay while I'm at it. Is there anything I can do for my starter? I was going to try cleaning it up tonight and pulling the solenoid off for a quick look over.

The starter in the wifes 96 was acting up and it turned out to be oil leaking onto (and into) the starter from the oil filter adapter.
The main wire from the starter relay, exits the relay box near the front, and then through a connector to the main solenoid wire. I haven't tried it, but it seems likely, a small jumper added to the solenoid wire connector could be sparked to the battery plus, as a test and in an emergency.
I seem to remember mixing and trying some different relays, when troubleshooting the starter. The relays looked a little small for the job they were doing, the solenoid draws quit a few amps. The wire exiting the relay/fuse box that connected to the main solenoid wire, didn't look big enough to power a dome light.

DeftwillP said:

I'll try putting the starter back in the morning and pick up a new relay while I'm at it. Is there anything I can do for my starter? I was going to try cleaning it up tonight and pulling the solenoid off for a quick look over.

Click to expand...

If there is oil on the outside of the starter, pull off the back cover and spray the brushes with brake cleaner. It's a two person job to compress the four brushes and get the end cap back on.
Solenoids rarley go bad. Most times it's the starter brushes or something in the wiring (relay, NSS etc.)

It is covered in oil. That was the plan to keep it from rusting.
I'll try that tonight too.

DeftwillP said:

It is covered in oil. That was the plan to keep it from rusting.
I'll try that tonight too.

Click to expand...

After the third time removing the wifes stater to spray the oil off of the brushes, I used a small paint brush and some RTV to seal up the seems and oil entry points. One day soon; I'm gonna have to put new "O" rings in the filter adapter.
If you split the starter, mark the end, center and front, in a line, it eliminates guess work. Try to get the back end off without dislodging the center section from the front, but if it pops off don't panic (unless you forgot the marks :laugh3: ).
On the end of the shaft, on some models, there is a washer inside the bushing/bearing in the end cap. The washer/spacer is easy to drop and overlook. But I'm pretty sure your Mopar starter has another end cap and doesn't have the washer.

Also try to put the shifter in the neutral position to check the NSS
Mine will fail to start in the park position every once a great while
And If your starter has the drain hole in the rear cover you can use electronic cleaner and spray through the drain hole to clean the brushes instead of removing the cover.
Check that you are getting power to the starter solenoid can just test the single wire from the relay to the starter solenoid with a meter, or if no meter avil, just jump 12v to the solenoid with a jumper wire

Had a similar problem...daughter called said the XJ wouldn't start.So when I get there,I told her to turn the key....NADA.
Pulled battery cables..cleaned posts...tried it again...NADA
Had XJ towed to house..slide under to remove starter
Prob# 1 Starter bolts were loose..both
Figured WTH take it to Autozone have it checkd anyway...on the tester checkd OK
Picked up starter by solinoid....solinoid was loose.....parts guy put it back on tester...hooked it up and as he tested it would move the solinoid which would not kick out the gear to engage the flywheel.....
On the upside...Starter was Autozone w/LTW....went back home slide under put NEW starter in and this time put lock washers on bolts....Problem gone

Problem solved. After reading everything on here, I went back this morning and put the starter on the truck and made sure to whack it a couple of times with a hammer. Previous to doing this, I sprayed sensor safe carb cleaner over the exterior and wiped it down. It started up no prob.

For the people that have to use the hammer method occasionally, is this a sign that it will go out soon? It is the stock starter with over 130K on the clock. I was going to go ahead and buy an aftermarket or rebuilt unit online as well as pick up a relay or two. What could it hurt?

It could be. The typical problem fixed by "impact maintenance" is that the brushes are sticking - so they're either contaminated with something (and should be torn down and cleaned) or they're getting short (and should be replaced.) Either way, you've got some work to do.

Problem is, rebuild parts for assemblies like this aren't as easy to find as they were ten years ago - people just aren't into fixing just what needs fixing, it's easier to just replace the thing (it's typically less work, since it becomes a straight R&I.)

Definitely pick up some relays, since they're handy to have around anyhow. I also use them when adding lights - mostly to standardise (all of the other relays are Bosch/Hella, so that simplifies the logistic train.) If you're thinking about a starter, why not give Rod a call - you can find out about him on my site. I get all my starters and alternators for him - personal use and paying jobs - and I've never had any trouble with his work. He's willing to ship, and if we can get some more business to him for common stuff through us, I could try to talk him into specialty goodies...

5-90

having to whack a starter is usally a sign that you need to replace it. There's usually a problem with the brushes or the stator. Whacking it will become a more frequent occurence, and then one day it just won't work.