90 XJ - no crank

I know this topic has been covered to death, but I want to sanity check my thoughts -

My '90 XJ 4.0 Automatic was sitting for two + years. I recently resurected it and it's been running great for a few weeks. I drive about 5 miles to and from the train station with it every day.

Three days ago I came back to the truck after work, got in, turned the key and nothing. No lights, no power to anything. Moved the shifter around thinking NSS, tried a couple of times, and within a 30 seconds or a minute the interior lights came on and I could hear the fuel pump wind up, but when I turned the key, nothing.

I'm thinking battery, right? No. I tried jumping it, and nothing. So I thought starter relay or starter. I replaced the relay first (local carquest had one) but that did nothing. Replaced the starter (had meant to do that since it has been sitting for so long and had rust on the terminals) and still no go. I put the old relay back, jumped it again and it started. The battery was weak so I took it home and threw it on the charger.

Go out this morning, charger says the battery is fully charged, turn the key, no go. Same thing. No lights, no nothing. I leave the key in the ignition and the door open, go around to the hood and I hear the door open buzz start to weakly come on. After about a minute or two the buzz is strong, the interior lights are on and the truck starts.

So, what is wrong? I'm thinking:
1) Bad battery - it's new, but cheapo Autozone, so could just be bad. Will tryr to get a load test tomorrow.
2) Bad ground - the cables are all heavy duty cables from Jeepers and Creepers, battery terminals are clean. The B- to block is dirty at the block (oil), so this will be cleaned tomorrow. The ribbon cable is stock, but doesn't look bad. I will replace to be sure....

I'm ruling out the NSS since I don't have power when I turn the key. The fact that power seems to come on slowly seems to me a symptom of a high resistance connection somewhere that is eventually giving way. Does that seem right? If so, I'm leaning toward ground, but honestly I'm a bit stumped.

Any ideas are greatly appreciated!

Bad/corroded cables and grounds.

Your first clue is a lack of headlights. The headlights are an unswitched circuit running of the PDC (Renix starter relay--the large lug) protected by a fusible link. The fact they don't work is telling you that there is no complete circuit.

Clean all the cables, both ends, renew all of your grounds. Once you ALWAYS have power to the light circuit, then if you have a "no crank" issue you can work only on that circuit.

That's first tomorrow.

I was thinking of adding a ground from the B- to the fenderwell too - should clean up any remaining gound issues.

Thoughts?

Good idea, the head-to-firewall braided strap is the one-and-only unibody ground on the early XJs. Adding a second unibody ground is a very good mod. I don't care for those braided straps and replaced mine with a 2 ga cable.

Cables from 5-90 ordered today.

I cleaned up the B- to block ground - there was some oil and crud on there (I think I have some gasket work to do soon), then I checked the braided strap. Firewall end is fine, the head bolt has some rust. I put some PB blaster on there for now.

After that she started right up and has been fine. Whew!

I'm still going to replace the braided cable and add the additional ground. I don't want to get stuck like that again.

You won't regret going with 5-90's cables, I have been running them for about two years--great pieces, real quality in the components and assembly.

joe_peters said:

You won't regret going with 5-90's cables, I have been running them for about two years--great pieces, real quality in the components and assembly.

Click to expand...

Best thing you could do!!!!!!!!