What could cause the heater blower to work intermittently in a 1988 Jeep Cherokee?

Answer 1

under the dash pass. side look at heater you will see a plug with several wires that look like thy go into the heater there is a one screw plastic cover over this area so your feet dont hit it remove then uplug the wires then take the 2 screws out of oval shaped sensor and pull it out of heater you will see some transister on the back side and a little coil . replacing this will cure it usually . but first remove your heater blower and make sure it turns freely and not seizing.

Answer 2

The heated seat system is capable of performing some self-diagnostics. The following table depicts the various failure modes which will be reported to the occupant via flashing the momentary switch telltales. The switch telltales will flash on the driver's switch if the failure exists in the driver's seat portion of the system, similarly with the passenger's switch. The telltale will illuminate for approximately a 1/2 second on, 1/2 second off pulse for a duration of one minute. This process will repeat every time the system is initiated via the switches until the problem has been corrected Before testing the individual components in the heated seat system, check the following:

If the heated seat switch back lighting does not illuminate with the ignition switch in the ON position, check the fuse in the junction block.

If the heated seat switch back lighting illuminates with the ignition switch in the ON position, but the heating elements do not heat and the telltales do not illuminate, check the circuit breaker in the junction block.

Answer 3

Hi,

Check for loose connections by moving wires side to side -gently don't overdo and create a problem- to see if it makes a difference and also do this to the wiring harness as maybe one is pinched, frayed coating and causing a short, etc., bad wires to your connections and your fuses/relays and see that one is not fried. If you do not know what to check you should get a book on your vehicle and look up trouble shooting or relays in electrical to start. We had this problem and it turned out to be a fried relay of which we were able to get at NAPA Auto Parts for just under $20.00. Be aware prices change in two years may be a bit more or less now. Repairmanual.com is a source of manuals, Motorbooks.com will give you an idea of the book you will need if you go that route. We bought ours at AutoZone, I believe for $20.00, has come in handy many times. It has diagrams for locating the relays and the wiring schematics for where it all leads to.

The Power Distribution Center in the Engine compartment contains Fuses and Relays.

Some are under the cover in the Glove Box Compartment, Kick Panel on the right side facing window (some are located here), and also the interior Fuse/Relay box on later models.

You may have more than one fuse/relay fried/not working. You need to check to be sure with a meter or someone who can use one or go to a garage and have them check this. If you change a fuse /relay and it immediately blows you need to find out why before proceeding or it will continue and still not get to run what is wrong.

Or, if you have some good fuses/relays handy and you want to pull one at a time and try replacing and see if you can locate it that way is another option. May be more or less time consuming and you have to have the correct fuse/relay for each one to work/check out properly. We always save our fuses/relays from cars we junked or dumped and have found them to come in very handy for this very type of situation. Not sure how mechanically/electrically knowledgeable you are so it makes it harder to figure and not enough supporting info due to lack of space here.

You would be wise to get the book or go on-line and see if you can find and on-line manual and look up what you need that way. It helps to know what you are looking for and where and why and the book also has pictures for location(s) to do all this.

There are Jeep forums that are very helpful. I hope I spelled it correct edmunds.com, Autogeek.com, Autorepair.about.com, fixya.com, autoanything.com, jeepfan.com to name some and others that you may be able to jump off of these sites links.

Good luck, hope some part of this is of help to you.

Answer 4

Which part isn't working? Is it blowing air but it stays cold, is it not blowing at all or is it just blowing to the defroster?

Answer 5

Loose wire on blower motor? Broken bower motor resistor? Bad blower motor? Loose fuse in fuse holder? Bad fan switch?

Answer 6

Because Jeep was well known for using an over-sized radiator in their 90's vehicles. Because Jeep was well known for using an over-sized radiator in their 90's vehicles.