1997 ford ranger heater motor issue
 

hi i am new here and not great with electrical but can manage
heres the deal i have a 1997 ford ranger 2wd 2.3L 5spd with a/c 233,000 miles i just replaced the heater blower motor resistor as the old one was rusted bad as was the pig tail going to it bad that one of the terminals broke off and was rusted in the harness so i replaced the plug as well problem is i still have no fan if i jump it it works but have no power at the plug for resistor or motor and no power at the switch inside the truck i do have power to one terminal where the relay plugs in any idea where to look next? thanks in advance

You can find the wiring diagram here: http://search.ebscohost.com/

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i am no good with diagrams i am a hands on type but this has me baffled

Welcome to FTE.
Since you don't have power at the IP switches, check the IP & under hood power distribution box fuse panels for a blown fuse, or a faulty blower motor power relay(relay location #2). EDIT: If you don't have an owners manual, you can download one here. https://www.fleet.ford.com/maintenan...ls/default.asp

fuses are all good relay seems to be under the air filter housing behind the passenger headlight on rad support i tried swapping that out already still nothing i am working on trying a back probe with 12v lead to see what it does then

Does the 40 amp blower motor fuse in the under hood power distribution box check ok????

If so, move to the under hood blower motor power relay & check to see if its getting 12 volts input from the 40 amp fuse on the PK/White lead & out of the power relay on the O/BK lead that feeds power to the blower motor resistor assy you just replaced. If power is getting to the resistor assy, but not to the IP switch assy, suspect splice S114, or connector C135m/C135f on the O/BK lead that goes to the IP heater control assy C232 electrical connector.

If you don't have 12 volts B+ at the C232 electrical connector, as has been said above, suspect a wiring, splice, or electrical connector problem on the O/BK lead between the IP connector & O/BK wire splice between the blower motor & blower motor resistor assy.

yes the 40 amp fuse is good and i have power at the relay but no power at the motor,resistor or switch i am really debating just putting it on a toggle switch and then its on or off as i am not pulling the dah apart to chase all the wiring i did take lower pannel off dash and found that someone appears to have added a remote start or something on the truck i never would have on a standard but the wiring around it is a nightmare so i don't want to mess with it truck is in great shape

OK, lets think about this some more. If you don't have power to the blower motor resistor assy, then the problem is between it & the under hood power relay, on the O/BK wire, more specifically since you don't have power to the IP motor switch, the open lead probably lies between the O/BK wire output connection on the blower motor power relay & splice on the O/BK wire, as power is split off at the splice, to go to the IP heater controls & the resistor pack. So somewhere under hood, between the under hood blower motor motor power relay O/BK lead to the splice, the O/BK lead is open.
If you rig a 12 volt test lamp, beeper, your multimeter, or listen for the blower motor to turn on, wiggle, flex, pull, push. or otherwise bend the O/BK leads wiring harness between the power relay & resistor pack & see if you can cause it to make contact & thus narrow down where the lead is open.

Suspect spots would be where the wire bundle makes a sharp bend, lays on/touches something that's hot, or moves/vibrates.

pawpaw i will look into it i am better with dang mechanical stuff this electrical crap drives me nuts as so many things could cause the simplest of issues i will see what i can find just haven't had much motivation today to mess with it needed a break from messing with it to approach with a level head

OK, your clues seem to have narrowed down your trouble shoot considerably, so let us know how it goes when you feel like getting back at it.

will do most likely sunday im gonna try a jumper wire at the relay box that will give me an idea if the relay maybe bad and the used ones we tried are as well if not that will try back probing harness before the fan motor if all else fails it will be a toggle switch i got the truck dirt cheap and had to do minimal to it so far. only replaced front leaf spring hangers and replace gas tank straps as one was bad and they were only $28 for the pair and i had the one hanger from a truck i scrapped the other was $29. so as clean as truck is i want to keep it that way if i can

well i put a jumper wire on two of the ports where the relay goes and fan works on each speed setting but with relay in i get nothing relay will click but no fan with jumper wire it works really confused as to what in the world is going on

OK, good trouble shooting feedback. If the fan works with a jumper in place of the power relay, then the relays power switching contacts are suspect. Probably worn, or maybe corroded & making a poor, or high resistance contact, such that the fan electrical load demand causes enough voltage drop across the corroded/or worn contacts that the fan won't run. A 12 volt test lamp at the relay output leads to the fan motor would probably be dim, or not light up at all, or your multimeter on the 20 volt DC range, would read well below B+ voltage.

Anyway, right now with your latest trouble shoot input, it sounds like the power relay belongs up there on your suspect list.

well i tried putting in a known good relay from the main power box and same thing fan don't work my friend may have another blower motor might just try it with relay in see if perhaps motor is drawing too hard previous owner said he had fan and relay replaced but still had issue but i am only jumping 2 of the 4 spots in relay box as those were the ones that worked. motor does sound like its chewing something up when running but box looked clear when i had motor out to replace the resistor as it was easier that way

ok here is what i got so far will try to make somewhat of a pic of what is going on in relay box will just use numbers 1 to 4 for reference i am jumping from #3 to #4 and blower works with ignition and on all speeds not posting as i would like it to look

1 _
2 : : 4
3 :