Jeep Creep: Jeep Tech and Maintenance Help

Nov. 28, 2016 By Jim Brightly, KF7SCT

In your Jeep Creep questions, please list your first and last names, your hometown, and your state/province/country, so that we can publish that information here. If you donít provide this information, we may not be able to publish your question and answer. Donít forget to be as complete as possible with the description of your Jeep and its problems, too. Send your Jeep questions to editor@off-road.com, Attn: Jeep Creep.

More Jeep Creep Q&As
October 2016 - Off-Road Tire Upgrades, Winter Prep and More

September 2016 - Air Horns and Communications Add-Ons

August 2016 - O2 Sensor Codes, Axle Conversion and More

One Jeep recallsfrom NHTSA this month
(www-odi.nhtsa.dot.gov/recalls/monthlyreports.cfm)
16V-734: Chrysler is recalling certain model year 2016-2017 Jeep Wrangler vehicles manufactured June 16, 2015, to August 14, 2016. In certain crash conditions, the front impact sensor wiring may be pulled until it detaches before a signal can be received by the Occupant Restraint Controller (ORC). If the ORC module does not receive a signal from the front impact sensor, both frontal air bags and the seat belt pretensioners will not deploy in the event of a crash, increasing the risk of injury. Chrysler will notify owners, and dealers will reroute the front impact sensor wiring and relocate the impact sensor branch, free of charge. The manufacturer has not yet provided a notification schedule. Owners may contact Chrysler customer service at 800-853-1403. Chryslerís number for this recall is S76.

Engine Swap
I have a 1989 Jeep Cherokee Pioneer with the six-cylinder 4.0L. Can I put a 318 Dodge V8 in it? I canít find anything on that swap.
John Weller
Logan, Utah

You sure can, John. You can install almost any engine into almost any Jeep, providing you have the patience, ability, money and equipment. However, there are several enginesómainly Chevy or Jeepóthat would be much easier to install. Contact Advance Adapters to ascertain if the company makes the adapter, motor mounts, etc., that youíll need. Iím also sure you can get a wiring loom from Painless Wiring, even if it has to be custom crafted.

Mad Module
I have a 1989 Jeep Wrangler Laredo 4.2L. I lost power going to the distributor, so I replaced the ignition module. It cranked fine for a couple days. Now I have no fire at the distributor again.
Steve Young
Johnsonville, NC

Steve, this is the same ignition module my Scrambler had. I remember I had to replace two of them on one Rubicon trail trip before we even left the pavement, so I started carrying a spare and never had to use it. You should have the Jeep/Motorcraft blue grommet module. You need to buy a name brand unit as the cheaper ones have a high failure rate. Since youíve already suffered one failure, I suggest you buy two and carry the spare, which will probably mean youíll never have to change it again.

Upgraded Ignition
I have a 1988 YJ 4.2L bored 60 over, ported/polished head, cam upgrade, four-barrel carburetor, and headers. Itís all for off-road use. Now I want to upgrade the ignition system. I was thinking about MSD. What would you suggest?
Will Battles
Tampa Bay, Florida

That sounds like an excellent idea to me, Will. In fact you probably should have done that much earlier in the rebuild. And your Jeep doesnít sound too bad either. Depending on what MSD kit you purchase, you may also need a module to drive the tach, if you have one.


Goofy Gauges
The instrumentation of my daughterís 1998 Grand Cherokeeís, which we bought used, fades in and out. The instruments will go out for a while then come back on. Also, there are a couple of dark areas in the cluster. Have you any suggestions to fix this economically?
Bill Brolander
Trenton, NJ

Bill, the instrument cluster needs to be repaired, rebuilt, or replaced with a known-good unit from a junkyard. As you remove the defective cluster, make detailed notes and/or pictures of each procedure so that you can replicate them on the reconnect.


No Heater
I have a 1995 Wrangler YJ. My heater quit working. I checked the fuses and that didnít do it. I was wondering if you could help me.
Moses Gordon
Marshall, IN

Moses, if you checked on both sides of the fuse for juice, what you need to do now is trace the wiring. I know itís going to be difficult, but it could save you some money. Check for juice on both sides of the switches, then at the motor itself (make sure the switch is on when you check at the motor). If juice is present at all these locations, youíll probably need to replace the fan motor. By the way, I forgot to ask if itís just the fan motorówhich I assumed from you checking the fusesóor is there no heat coming from the registers at all? If itís no heat at all, it could be the vacuum duct switching controls.


Wrangler S?
I just purchased a Ď94 Jeep Wrangler. When I took it to get insurance on it I was told that itís an SE. But when I look it up on NADA, there is no Ď94 Jeep Wrangler SE. Can you help me figure this out? Iím really just trying to see if I overpaid for the vehicle.
Otto Vincente
Commerce, CA

Since you didnít mention a price, Otto, Iím not sure whether you paid too much or not. But according to my library, the ďSĒ and ďSEĒ model names were interchangeable at different points in the model run and were the base models. During the first few years the backseat and rear bumperettes were optional, some years the six-cylinder engine was an option, other years only the four-cylinder engine was available in the ďbaseĒ model.


Brake Warning Light
I have an Ď86 CJ7. I had a front brake line break. After replacing the line, refilling the reservoir, and bleeding the brakes, I still have the brake warning light on. How do I remedy this?
Bill Smithson
Gaviota, CA

Your proportioning valve needs to be adjusted. Youíll find all the necessary information in a Clymer or Chilton Jeep manual, which you can find at any auto parts store.


No Heat Jeep
I have quick question. Iím new to Jeeps, but just wondering why my 1990 Wrangler only has heat blowing from the defrost and floor vents? Is this normal? This barely heats my Jeep. If this isnít normal, have you any ideas on how to make it blow from the dash vents?
Rick Rickman
Bremerton, WN

This is normal. The dash vents are for air conditioning. Two things you could do: Examine all the heater ďductsĒ or hoses under the dash to make sure they arenít kinked, loose, or clogged. Make sure youíre getting as much air flow at the ends of the hoses as you are at the heater. Another thing: If you donít have a full carpet kit, a full carpet kit would insulate the floor and help warm up the Jeep. In addition, 4Wheel Parts offers a 12VDC backseat heater that mounts on the floor. This should keep your toes toasty. One more thing I just remembered. Some of the Toyota FJ40s were equipped with a roundish heater in the backseat area. This heater connected to the engine cooling system with hoses just like your stock heater, and it was equipped with a fan that blew heat out a 360-degree circle. If you could find an old FJ40 in a junkyard you might be able to rescue one of these heaters.

In your Jeep Creep questions, please list your first and last names, your hometown, and your state/province/country, so that we can publish that information here. If you donít provide this information, we may not be able to publish your question and answer. Donít forget to be as complete as possible with the description of your Jeep and its problems, too.

For some reason the questions have fallen off, and I know we havenít answered all your Jeep technical questions. There are no dumb questions; only unasked questions. Send them in and try to stump us.óJim Brightly

Send your Jeep questions to editor@off-road.com, Attn: Jeep Creep.

More Jeep Creep Q&As
October 2016 - Off-Road Tire Upgrades, Winter Prep and More

September 2016 - Air Horns and Communications Add-Ons

August 2016 - O2 Sensor Codes, Axle Conversion and More

As usual, each month, Iím shouting out a huge THANK YOU to Paul Schupp at Rock Lizard 4x4 in Kingman, Arizona, for his invaluable assistance in answering many of the Jeep Creep questions.


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