Rogue401

Hi All,
Long time reader, first post. I just wanted to let you know what I found while replacing my CPS. We have a 97 Cherokee Country with about 118,000 miles that we bought new. It's in great shape and has been well cared for except for being rear ended very hard in 2001.

A couple of nights ago we were 1/2 mile from home and it just shut off. First thought was that it ran out of gas. It started right back up, but ran terrible and stalled a couple of times and wouldn't idle at all. I nursed it back home and went out the morning and the two year old battery was flat dead. It measured 6.5 volts. Cleaned all the terminals and put my charger on it. Had AutoZone check the battery and it was OK.

I read the codes in the odometer and came up with 55, 11, 11, 12. Then I started searching the forums and came up with the CPS. I unplugged it and connected it again and the Jeep started right up and ran better but not great. Then the power door locks started cycling and then I noticed the interior lights wouldn't shut off. I pulled the fuses for the power door locks and interior lights and they all stayed on. I finally pulled the large fuse for the headlight switch and that killed the interior lights, but not the door locks.

I gave up on that for a while and decided to change the CPS. As I was trying to move the harness out of the way to get my hand down there from above, the engine/body ground strap fell off! There is a small braided strap from a headbolt to the firewall right in plain sight on the drivers side near the center of the firewall above the large wire loom. It bolted to the body with a 15mm bolt. The ground strap was corroded green and just broke off the terminal when I touched it.

I put a new end on it and started the Jeep up. The Check Engine light went off and then the Check Gauges light went off. Jeep runs perfect!! I'll replace the CPS just because it seams to be prone to fail eventually, but will wait until it's a little warmer.

I then went after the lights and door locks. Put the fuses back in and everything works as it should! Yeah!

I wonder how many electrical gremlins on here are caused by that crappy little body ground strap? I always tell my kid when he has electrical problems to check the grounds first. I should have followed my own advise.

Hope this helps someone?

Thanks for all the great posts on here!

bobvalli

Good story, good lesson

Thanks

tjwalker

Grounds are often overlooked and are the cause of many problems. We take "grounds" for granted until we have troubles. Ask any shop owner how often they check grounds for funky problems before looking elsewhere. They all will have the same answer.

The specific ground you mention is very prone to failure. Here is more...
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Grounds can be the root cause of many electrical gremlins. Refreshing grounds is NEVER a bad idea!

You can't just check or look at these grounds. Looking at them oftentimes doesn't tell the story. You must remove, scrape, clean until shiny the cable/wire ends and whatever they bolt to. The one on the back corner of the head, and where it attaches to the firewall. Scrape the paint from the firewall. Best to replace that woven cable with a #4 or #2 gauge cable. You can attach the one end to the intake manifold if you would like.

Next go over to the engine dipstick tube stud. Remove the nut and clean the wire ends and scrape the block until shiny at the stud. Reattach tightly.

If you are so inclined, add at least a #6 cable from the negative terminal of your battery to one of the bolts on your radiator support. Scrape the paint off first.

CJ7365

+1 on checking grounds

Rogue401

I should have learned my lesson the first time! We have a 1967 AMC Rambler American Rogue convertible with a AMC 401. We were at a car show in Cape Cod, MA. Got to a section of dangerous road and the sign said to turn on the headlights. So I pull the headlight switch and pooofff, the dashboard goes up in smoke. Thank God nothing else burned.

We've had this car for 30+ years and it's had 3 engines and been apart and painted twice, so I know my way around this thing very well. We went to a NAPA store who was very helpful and bought a new headlight switch for a boat, and a cheap circuit tester and some wire and terminals. After two days, I finally figured out that at that instant the contact between the pass side headlight bucket and the fender decided there was too much paint and wouldn't ground anymore. I didn't know why, but I ran a short wire between the headlight bucket and a fender bolt and fixed it. When we got home I rewired everything from the dash forward with a Painless Performance kit.

We also had trouble with starters cranking the 401 until I ran a separate ground cable from the starter bolt to the battery. Now it spins like crazy with a RobMac AMC starter.

Bustedback

Good info, and well detailed. A very useful post that should be stickied.

Roughcherokee95

Good info man! i had the same problem...

but my codes ran up TBS. Throttle body senor?..
anyways, did the same thing. Running ROUGH. idled very low.
and stalled.

MATT 87 CHEROKEE

Thanks this would have been nice to read a week ago...