Cali Cruse Posted October 20, 2018 Author Posted October 20, 2018 Would someone mind taking a picture of the exact location of the resistor pack? I hooked up old blower motor directly to the battery and it worked. Fuse was replaced. Would a resistor be an issue on a 1991? Thanks folks!
Ωhm Posted October 20, 2018 Posted October 20, 2018 7 minutes ago, Cali Cruse said: Fuse was replaced. Check the fuse again.
PCO6 Posted October 21, 2018 Posted October 21, 2018 On 10/17/2018 at 8:24 AM, cruiser54 said: … So your blower motor has its ground point 10 feet away from where it is located!! What the hell were they thinking? I just made this fix on my '89 XJ and my blower runs much better now. Thanks Cruiser! My '88 MJ blower runs fine but I'm going to fix it as well. Hope it won't run too fast!
Minuit Posted October 21, 2018 Posted October 21, 2018 2 hours ago, PCO6 said: What the hell were they thinking? So far, I'm not convinced they were.
cruiser54 Posted October 21, 2018 Posted October 21, 2018 2 hours ago, PCO6 said: What the hell were they thinking? I just made this fix on my '89 XJ and my blower runs much better now. Thanks Cruiser! My '88 MJ blower runs fine but I'm going to fix it as well. Hope it won't run too fast! great. Think of the reduced load on the fan switch and wiring.
PCO6 Posted October 21, 2018 Posted October 21, 2018 22 minutes ago, Minuit said: So far, I'm not convinced they were. LOL That ground wire alone is 2/3's of the overall length of a SWB MJ!
PCO6 Posted October 21, 2018 Posted October 21, 2018 9 minutes ago, cruiser54 said: great. Think of the reduced load on the fan switch and wiring. It's a reoccurring theme … lots of really fundamental design gafs looking for practical solutions. Your tips have proven this over and over again!
HOrnbrod Posted October 21, 2018 Posted October 21, 2018 6 minutes ago, PCO6 said: It's a reoccurring theme … lots of really fundamental design gafs looking for practical solutions. Your tips have proven this over and over again! 95% of those design gafs were gone when the HOs came out. For example the blower ground breaks out of the cross-body engine harness and grounds at the dipstick.
PCO6 Posted October 21, 2018 Posted October 21, 2018 1 hour ago, HOrnbrod said: 95% of those design gafs were gone when the HOs came out. For example the blower ground breaks out of the cross-body engine harness and grounds at the dipstick. That's one of the first ones I would have got rid of!
HOrnbrod Posted October 21, 2018 Posted October 21, 2018 11 minutes ago, PCO6 said: That's one of the first ones I would have got rid of! It's actually a stud on the engine block. Ground don't get much better than that.
PCO6 Posted October 21, 2018 Posted October 21, 2018 25 minutes ago, HOrnbrod said: It's actually a stud on the engine block. Ground don't get much better than that. I agree, grounding directly to the block is a good thing but the other wires could have been grounded to a different and more accessible location. The ones I've cleaned up have been an oily and somewhat frayed mess down there. I haven't looked at this carefully but I think that running a 4g cable back up to the fire wall and grounding the secondary wires there might be an option. I replaced the firewall ground strap on the left side with a 4g cable to the manifold. That's a bit far away but a similar thing on the right side might work.
Pete M Posted October 21, 2018 Posted October 21, 2018 ahhh, the delirious joys of owning a now decades old vehicle designed during the desperate, dying days of a small automotive manufacturer. plus throw some road salt into that wound for extra fun.
PCO6 Posted October 21, 2018 Posted October 21, 2018 39 minutes ago, Pete M said: ahhh, the delirious joys of owning a now decades old vehicle designed during the desperate, dying days of a small automotive manufacturer. plus throw some road salt into that wound for extra fun. LOL ... very true. BTW - road salt (= rust) is a good thing. It makes us better welders!
Pete M Posted October 21, 2018 Posted October 21, 2018 30 minutes ago, PCO6 said: LOL ... very true. BTW - road salt (= rust) is a good thing. It makes us better welders! haha! and better wiring technicians. and more skilled with the various tools needed to removed a snapped bolt. and...
Cali Cruse Posted October 21, 2018 Author Posted October 21, 2018 Indeed. So no luck at all after changing the fuse, the blower motor, the resistor pack. I even checked the terminals going into the plug. No power is coming from the female connector to the male from the blower motor. Still, thanks for all of the guidance, learned a lot about the truck.
JMO413 Posted October 25, 2018 Posted October 25, 2018 Replaced my resistor today an now I finally have all speeds! The Mopar resistor is even made in the USA!! Did the additional ground also and my high is definitely improved.
Cali Cruse Posted October 28, 2018 Author Posted October 28, 2018 I got it to work! It took about a week, but it came down to a fuse, don't laugh though because here's why: radio stopped working and when I pulled out that fuse I noticed it was a blown fuse that was an incorrect one from the prior owner at 30amp rather than light blue 15amp. I suspect, and I could be wrong, but I wonder if that fuse that's right next to the blower fuse had an effect on it since the brand new white 25 amp also busted. So I replaced both and now I got blower motor working full blast at all speeds and the radio is back from the dead too! Thanks for all the helpful data - wanted to thank you, but it took a week!
Pete M Posted October 28, 2018 Posted October 28, 2018 glad your story had a happy (albiet weird) ending! did you take the opportunity to add extra grounds to everything?
Minuit Posted October 28, 2018 Posted October 28, 2018 A fuse doesn't blow by itself. You've still got a problem elsewhere. The radio circuit should come nowhere near blowing a 15A fuse let alone a 30A fuse. I'd be looking awfully hard for an intermittent short to ground, perhaps a wire rubbing on something metal.
schardein Posted October 30, 2018 Posted October 30, 2018 It's a common problem that the wiring connection at the actual fan switch got hot and melts. This, in addition to the other things already discussed (resistor pack, grounds). Read through and didn't see it mentioned, so thought I would add it. If you are doing the work, might was well check the whole circuit.
Cali Cruse Posted November 13, 2018 Author Posted November 13, 2018 Still shorting. Blew a fuse today after 50 mins of driving and blower motor was running fine. Checking power at connector to blower motor, resistor pack, and fuse gate. Will look for a wire touching metal. Needle in a haystack isn't it? Ha!
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