Question about 1990 GMC C1500

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Wiring harness burnt up need a new one

Okay here is my problem a rag or something fell down by the motor and burnt the plug wires, the radiator hoses, and the main wiring harness that goes through the fire wall on the passanger side. its a 1990 GMC 1500 SLE pickup what i need to do is find a new engine wiring harness or the plug that goes through the fire wall1990 GMC pickup

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Try the Dealer,a Salvage Yard for a similar vehicle. Then assuming you have enough left you could make one or at least I could by copying the burnt remains. Still need scrap connector if they melted. You may find plugs as you said from many GM veh of different years. Also check the ads in Street Rod ,Rod & Custom for companies that will make you what you need. Hopefully you can find a way without parting with the cash Now the real question, did you take out any electrical or electronics during the melting process. Been there 40 years ago on a 65 Corvette I bought new.

Posted on Sep 28, 2009

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Go to a salvage yard and get a new harness, And you need a book on it to help you run it down. It will take some time but you can do it.

Posted on Sep 28, 2009


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2005 yukon, new blower motor, new resistor,new wiring harness. still no front ac. put meter on red and black at harness that plugs into resistor, 14.4 volts, turn ac control head from 1 to 5 and no voltage...

If you can work back on the wires to see if you are getting power anywhere along the harness. It could just be the clip. In which case you can most likely get a replacement for cheap at the dealership.

Aug 07, 2014 | 2005 GMC Yukon

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Air works but it dosent blow anymore I was thinking the blower motor or the switch

Hello: It could be the blower motor but first check the wires (6) going to the blower motor from the module (under the passenger side dash close to the blower motor and check the wires going from the (2) module to the blower motor. The module itself may be burnt where the 6 wire connector plugs in. If so the module will have to be replaced. GM sells a harness so you can replace the burnt connector, just connect the new harness one wire at a time. Make sure you orientate the new connector like the old so you get the wires in the correct order.

Jun 15, 2011 | 1999 Chevrolet Silverado 1500

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Sep 09, 2010 | Ford Thunderbird Cars & Trucks

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!997 Chevrolet Cavalier 2.2 with AC \Radiator fan motor replacement. I have diagnosed fan motor, have it detached but not get it out with fan and shroud to replace the motor. Ac lines are in the way on...

Alternative Method - Radiator Removal
Fig. 14: Use a piece of wire or another suitable device to support the condenser before removal of the radiator 91143p41.jpg
Fig. 15: Remove the front bolt on the suspension support arm 91143p33.jpg
Fig. 16: Loosen the rear suspension support arm bolt and swing the arm down out of the way 91143p48.jpg
Fig. 17: Remove the wire harness retaining clips from the radiator support bar 91143p36.jpg
Fig. 18: Remove the retaining clips on the radiator support bar for the splash shield 91143p34.jpg
Fig. 19: Remove the four bolts on each side (only three shown in the photo) for the radiator support bar and . . . 91143p35.jpg
Fig. 20: . . . remove the support bar. 91143p37.jpg
Fig. 21: Carefully lower the radiator out the bottom of the engine compartment 91143p49.jpg
NOTE: When adding coolant, it is very important to use GM Goodwrench DEX-COOL® , which is an orange colored, silicate free coolant. If silicated coolant is used on these vehicles, premature engine, heater core and/or radiator corrosion may result. In addition, the engine coolant will require change sooner, at 30,000 miles (50,000km) or 24 months.
  1. Disconnect the negative battery cable.
  2. Properly drain and recover the coolant in an approved container.
  3. Disconnect the upper transaxle oil cooler line from the radiator and plug the line to avoid contamination.
  4. Detach the upper radiator hose from the radiator.
  5. Disconnect the overflow hose from the radiator.
  6. Support the condenser with some mechanics wire or other suitable device.
  7. Raise and safely support the vehicle.
  8. Remove the cooling fan assembly. For details, please refer to the procedure located later in this section.
  9. Disconnect the lower radiator hose from the radiator.
  10. Unfasten the lower transaxle oil cooler line from the radiator.
  11. Remove the front bolt from the suspension support arm.
  12. Loosen the rear suspension support arm bolt and swing the arm down out of the way.
  13. Remove the wire harness retaining clips from the radiator support bar.
  14. Remove the retaining clips on the radiator support bar for the splash shield.
  15. Remove the four bolts on each side for the radiator support bar and remove the support bar.
  16. Have an assistant support the radiator and remove the two radiator-to-condenser bolts, one on each side.
  17. Carefully lower the radiator out the bottom of the vehicle. To install:
  18. Position the radiator assembly into the vehicle.
  19. Have an assistant support the radiator and install the two radiator-to-condenser bolts.
  20. Place the radiator support bar into place and finger-tighten the retaining bolts. Tighten the bolts to 18 ft. lbs. (25 Nm).
  21. Raise the suspension support arm and attach the front bolt finger-tight. Tighten the rear bolt and then the front bolt to 18 ft. lbs. (25 Nm).
  22. Attach the wire harness retaining clips onto the radiator support bar.
  23. Install the retaining clips on the radiator support bar for the splash shield.
  24. Fasten the lower transaxle oil cooler line to the radiator.
  25. Connect the lower radiator hose.
  26. Install the cooling fan assembly, as outlined later in this section.
  27. Carefully lower the vehicle.
  28. Remove the condenser support wire or other device.
  29. Fasten the overflow hose to the radiator.
  30. Attach the upper radiator hose.
  31. Fasten the upper transaxle oil cooler line to the radiator.
  32. Connect the negative battery cable.
  33. Fill the cooling system with the proper 50⁄50 mix of DEX-COOL coolant and distilled water.
  34. Bleed the cooling system.
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Aug 13, 2010 | 1996 Chevrolet Cavalier

2 Answers

1998 Jeep Grand Cherokee 5.9 V8. Radiator cooling fan motor burnt up. Need to find replacement. What we are finding only have 2 wires coming out of motor, we had 3. Connecting wires have 3. What do these...

Since the 5.9 electric fan motor cannot be purchased anywhere but from the dealership and for several hundred dollars, here's how I replaced mine. 1998-2000 Ford Crown Vics, Lincoln Town cars and Mercury Grand Marquis have exactly the same electric motor in them with a different style 3 wire connector. The part # at Autozone is PM9069, comes with a lifetime warranty and cost me 119.99 on 8-30-08. The only trick is getting the connector from the junkyard from one of the above vehicles. I got one from a Grand Marquis and a second from a Lincoln 100 feet away (I have 2 5.9s and I'm planning for the future on the second one). If you're really pressed for cash, take the motor from the junkyard too and hope it works. Watch the Lincolns as they have the correct motor and connector on the driver's side of the radiator and a second motor on the passenger side of the radiator which only has a 2 wire connector. If you get this connector and/or motor you'll only have hi speed or low speed depending on how you wire it, but not both. I cut the connectors off with about 6 inches of wire. The 2 connectors cost me $5. Once you've removed your old fan motor from the fan blade and the shroud and you have it sitting on the top of the radiator still plugged in, sit your new motor with the junkyard plug in it beside the bad motor. The center wire is the ground. I think the right wire was the high speed and the left wire was the lo speed. The high speed wire is the red with white stripe wire. It doesn't really matter as the Lincoln wiring is a different color. As long as you cut the left or right wires at the connector on the harness side of the connector ONE at a time, strip it and attach it to the same left or right stripped wire on the connector on your new motor, it works perfectly. At the very least, put a piece of masking tape labeled either left or right on the two wires since it's easier to cut all three and then solder with the old motor out of the way. You need to solder these wires as there's a lot of juice going through them. Wire nuts will get corrosion in them and you'll have problems a couple years down the road. A pencil soldering isn't really hot enough. You need one of those trigger ones that get real hot as these wires are good size. If you happen to mix up the wires on your electric motor, it won't hurt anything. When the sensor in the driver's side upper radiator hose turns on the fan to low, it will always run on high speed instead of the intended low speed. The high speed sensor in the passenger side lower hose will basically not be doing anything because it would actually be turning on the low side of the motor. The high and low are seperate in the motor. You do not need the low side running to get the motor onto high. I've heard this debated and ran my new motor on high and low seperately with jumper cables to find out before I installed it. The only other consequence of incorrect wiring is when the AC is on which normally runs the fan on low, it will now run on high. It doesn't hurt anything and cools better, but it is noisier. I considered wiring it backwards on purpose to get more cooling earlier, but finally decided to wire it correctly and let the sensors do their job. You won't have any problems as long as you still have the original 150 amp alternator in there(56041 394AA on the silver sticker). You can't buy the 150 amp alternator at the parts stores. If somebody's put in a 90, 117, or 120 amp you could have some dimming when the fan kicks on. The 136 amp which is the biggest the parts stores list for a 96-98 grand cherokee would probably be okay. When the 150 amp ones go bad, it's fairly simple to put new bearings and brushes in them. The hard part is getting the pulley off. If you still have the factory thermostat in your 5.9 (it runs 210 on the temperature guage ALL the time), you'll notice your electric fan never shuts off. That's probably contributed to these fans burning up and seizing. The low side kicks on around 200 and the high side about 215. So with the original thermostat, the fan is on low as soon as the thermostat opens and never shuts off. Both my 5.9's had the fan running all the time when I purchased them, one with 22,000 and the other with 48,000 miles. Of course I ran to the dealership for a new sensor in the top radiator hose for one of them which did exactly nothing to fix the problem. I finally unplugged the harness from the low speed sensor, filled the sensor and harness connector with grease to keep out the corrosion, zip tied it to the power steering hose, and I've run both of them for 8 years or so with just the high speed sensor cooling things down. When the water pump went bad in one of them 2 years ago at 160,000 miles, I put in a 185 degree thermostat as well, plugged the sensor back in, and now it works perfectly. By the way, the 25 degree drop in temperature really cut down on my heat in the winter. If you live north of I-80 or so, I'd leave the original thermostat in there. Or go to a 195 degree thermostat. That's going to be real close on whether the fan will be running all the time or not. It should be okay, but you'll have the fan coming on every two or three minutes in city driving. What really wears these fans out is miles. When you're driving down the road and the fan is not running, it's still spinning like crazy in there from the air going through the radiator, and that's accumulative wear on the bearings. Back to the soldering, if you want a neat looking job, slide some shrink tubing on the wiring before you hook them together and shrink it down when you're done or use electrical tape. I ended up with 8 inches or so of excess wiring which I have zip tied to the radiator support just below the radiator cap. Now you've got a fan motor with a lifetime warranty. If it ever goes bad, you get a free one. Hope this helps other 5.9 owners, because I searched in vain for 3 months for a way to fix this. It wasn't until a Jeep mechanic mentioned certain Ford big cars had a motor like the bad one I was carring around that I got pointed in the right direction and found the years and models on my own. I was driving it around without a fan because I live in the country without much traffic. If you live in the city, you couldn't do that or risk melting the engine down.

May 17, 2010 | 1998 Jeep Grand Cherokee

1 Answer


yes the entire idler arm needs replacement to clear this problem.
there are many things to be checked
just click this link directly
you will need to remove the alternator to replace the idler arm pulley
Disconnect the negative, then the positive battery cables.
Remove the battery from the vehicle.
Remove the battery tray using the following procedure:
Remove the four battery tray bolts.
Remove the battery tray from the vehicle.
Remove the serpentine drive belt.
Remove the cooling fan assembly using the following procedure:
Remove the wishbone-shaped engine mount strut by removing the bolts and nuts at the engine mount bracket and on the upper radiator support.
Remove the strut from the vehicle.
Disconnect the cooling fan harness from the engine wiring harness.
Reposition the wiring harness at the upper radiator support.
Remove the cooling fan shroud bolts.
Remove the right side radiator bracket.
Remove the cooling fan shroud with the electric cooling fan motors and fans as an assembly.
Remove the thermostat housing and the radiator hose using the following procedure.
Partially drain the engine coolant.
Use hose clamp pliers to remove the radiator hose clamp to the water inlet housing and disconnect the radiator hose.
Use hose clamp pliers to remove the heater hose clamp to the water inlet housing and disconnect the heater hose from the water inlet housing.
Use hose clamp pliers to remove the surge tank inlet hose clamp from the water inlet housing and disconnect the surge tank hose from the water inlet housing.
Remove the water inlet housing bolts and remove the water inlet housing.
Remove the outboard generator bolt and loosen the inboard bolt.
Remove the idler pulley bolt and idler pulley.
Unplug the electrical connector from the alternator.
Pull back the protective boot from the alternator "BAT" terminal, remove the nut and disconnect the heavy "BAT" wire from the alternator terminal stud.
Remove the alternator from the vehicle.
To Install:
Position the alternator to the engine.
Plug in the electrical connectors and install the heavy "BAT" wire to the alternator terminal stud. Tighten the nut to 15 ft. lbs. (20 Nm). Press the protective boot back in place over the stud terminal and nut assembly.
Install the outboard alternator bolt into the alternator housing.
Install the inboard alternator bolt and then finger-tighten the outboard bolt.
Install the idler pulley and idler pulley bolt.
Tighten the bolts in the following torque sequence:
Tighten the idler pulley bolt to 37 ft lbs. (50 Nm).
Tighten the alternator bolts to 37 ft. lbs. (50 Nm).
Install the water inlet and thermostat housing and the radiator hose, observing the following:
Inspect and clean the mating surfaces on the thermostat cover and its mounting surface on the engine.
Use RTV Sealer GM #1052366 or equivalent on the mounting bolts since the threaded openings are open to the cooling system and the torque requirement is low.
Install the water inlet and thermostat housing and tighten the bolts to 80 inch lbs. (9 Nm).
Connect the surge tank inlet hose to the water inlet housing.
Connect the heater hose to the water inlet housing.
Connect the radiator hose to the water inlet housing.
Install the cooling fan assembly and tighten the radiator bracket bolts to 80 inch lbs. (9 Nm). Plug in the wiring harness at the upper radiator support. Plug in the cooling fan wiring harness to the engine wiring harness.
Install the engine mount strut bracket to the upper radiator support first, insert the through bolt. Attach the engine side of the strut to the engine mount strut bracket on the engine and install the through bolt. Thread the nuts on the through bolts and tighten to 35 ft. lbs. (48 Nm).
Install the battery tray and tighten the bolts to 44 inch lbs. (5 Nm).
Install the battery.
Install the serpentine drive belt.
Connect the positive, then the negative battery cables.

This will help. Thanks please keep updated. please do rate the solution positively .thank you for using fixya.

Nov 23, 2009 | 1999 Chevrolet Tahoe

1 Answer


first drain the radiator, theres a drain **** at the bottom of the radiator. just loosen the plug and then open the radiator cap. then disconnect the upper and lower hoses, disconnect the trans lines and plug them temporarily with some spark plugs or just something to plug them with. unplug the radiator fans and remove the wire harness from the fan shrouds. then unbolt the two ten millimeter bolts holding in the radiator and remove it. then take the fan shroud off the old radiator and put it on the new one, should just be a couple ten millimeter bolts. then install in the reverse order. good luck!

Nov 12, 2009 | 1993 Lexus Es 300

1 Answer

7 wire harness going to blower motor resistor

There is an updated resistor/connector package. Very expensive from GM, try your local NAPA or other parts supplier for a replacement

Jul 09, 2009 | 1996 GMC Sierra

1 Answer

No 12V at Trailer Tow

you might search for a burnt fusible link that feeds that harness...try looking where the battery cable is connected to the starter motor underneath.sometimes you cant tell if a fuse wire is gotta tug on it slightly...if it stretches like rubber,the wire inside is burnt/separated and designed to do so there instead of frying the whole harness

Jun 23, 2009 | 1998 Ford F150 Regular Cab

1 Answer

Fan motor works on high

Really common problem on Fords. My '00 vic had it and my friends 06 mustang had it. The problem is the blower motor gets old and starts drawing too much amperage. The motor is controlled by (on manual HVAC systems) by a nichrome resistor bank located near the heater core. The extra amperage blows the thermo-resistor in the bank, and also does some damage to the corresponding harness. The reason it work's on "HIGH" is because that setting bypasses the bank completely. You can fix the problem pretty easily yourself but it is sort of annoying. First go get a new blower motor, either from Ford or some other place like Napa or autozone. Probably one of the latter because sometimes it seems dealer's aren't always the most cost effective solutions =] Now head on down to Ford and pick up the resistor bank (and most likely the harness, but check if it's burnt first) park your car, let it cool down, and pull off the radiator cap, keeping it on the hole (this keeps the pressure equal, and just set it on the hole so no random stuff gets in) pull off the coolant lines to the heator core, unbolt the resistor bank, set it next to the next new one, and wire up the new harness one wire at a time. plug in the new one, bolt it in, and reinstall the coolant lines. then put in the new blower motor, it should be on the lower passanger side on the engine bay. Now go enjoy your new fan speeds!

Sep 05, 2008 | 2007 Ford Crown Victoria LX Sedan

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