Gmc motorhome alternator wiring. org is not affiliated with General Motors Corporation.

Gmc motorhome alternator wiring. Jul 28, 2004 · The GMC Motorhome Forum is a place where owners and fans come together to have discussions and share information about the classic GMC Motorhome (VIN beginning with "TZE") and the adventures we have with them. 2 meg. Steve Southworth 1974 Glacier TZE064V100150 (for workin on) Nov 21, 2021 · There is a voltage feedback wire from the chassis wiring harness to the alternator. 02H with a part number of 7. This will charge the Onan battery whenever the front engine is started. If I remember correctly it was a double belt driven alternator. With the combiner the alternator output terminal's always hot, so I use an oil pressure switch. Jan 16, 2023 · It's not generally a good idea to use a one-wire alternator along with a battery isolator. Jan 8, 2009 · The GMC Motorhome Forum is a place where owners and fans come together to have discussions and share information about the classic GMC Motorhome (VIN beginning with "TZE") and the adventures we have with them. This extra resistance wire does not affect the functionality of the indicator light in any way. Aug 19, 2018 · the center (alternator) terminal to the front isolator center (alternator) terminal and one of the other terminals to the Onan start battery. Since our electrical appetite was so high (dash air blower, halogen Oct 2, 2024 · A better fix than the APC for the alternator exciter wiring overheating issue. The sense line is the light gauge red wire coming from the two-conductor plug on the Delco alternator. As far as the other wire sizes, its more a cost (Accountants driven) rather than minimal voltage drop decision. then the alternator light came on so i replaced the alternator. this also separates the 2 batteries but combines them whenever a charge source is present such as the alt. To provide fuel pressure during starting, the starter solenoid voltage is also provided to the selected fuel pump. 5V-13V. The reverse voltage glow did not cause any damage, but GMC did modify their production in 1977/78 models of the GMC Motorhome to eliminate the condition. A 4k Onan has a 35A breaker, so the wire needs to be 8 gauge (good for up to 40A). Even the 1977/78 models do not protect the Nichrome Resistance Wire! GMC published a Tech Note in 1974 to identify a problem that let the alternator light glow dimly on most GMC Motorhomes’. Oct 12, 2019 · The GMC Motorhome Forum is a place where owners and fans come together to have discussions and share information about the classic GMC Motorhome (VIN beginning with "TZE") and the adventures we have with them. In High, it only has to power the High-Speed relay coil and there is a separate 30 Amp fuse from the alternator to the high speed relay to run the blower on high speed. The #2 alternator pin should have a white wire, which splices into some red wires, and connects to the fusible link at the horn relay. Gmcmh Drawings Gmcmi. But 30 is not big enough for the alternator I'm running in the coach. 5 volts and blowing headlights (a problem that seemed to Apr 7, 2024 · The Alternator Exciter wire, also known as the “Nichrome” wire is a special purpose wire bundled into the chassis wiring harness. Put in second alternator same thing. The alternator also charges the house battery through the isolator. 2. This gets voltage from the flywheel alternator. Unless they have a drop-out under a set RPM, as long as the alternator can produce 13. I do not remember much more as that was 12 or 14 years ago that I saw it. If using the Alternator Protection Cable plug one end into the alternator and the other end into the wiring harness/pigtail. 5V at alternator brown wire I think I'll check again for voltage drop on the ground path between battery and engine. To parties of interest. Pay attention to the airflow through the alternator. I've read here before that the dim light is quirk of the GMC Aug 20, 2020 · I started up my GMC and everything was fine. Feb 17, 2019 · Also, on a one-wire alternator, once the RPMs have gone high enough for the alternator to self-excite, it should stay excited and producing power until the RPM's of the alternator fall well below idle. After 44 years, in S. Check carefully before using. Aug 15, 2008 · JimB pushes the one-wire alternator as his solution to the Nichrome (resistor) portion of the alternator exciter wire getting hot and melting insulation in the wiring harness. 00 The GMC Motorhome Forum is a place where owners and fans come together to have Aug 28, 2024 · The GMC Motorhome Forum is a place where owners and fans come together to have discussions and share information about the classic GMC Motorhome (VIN beginning with "TZE") and the adventures we have with them. MY ALTERNATOR DIED. Our last couple Onan start batteries lasted 10 years with this setup. GM 12SI alternators with a charge light have key on power to one side of the 194 bulb (a pink wire, usually fused on the gauges fuse) the other side of the bulb is connected to pin “2” of the alternator on a brown wire. 0. Trailer Wiring Diagrams Etrailer Com. Different baffling for the cooling air. I plan to break into the wire at the alternator, run up to the dash gauge and backa total of 10 ft. Feb 24, 2015 · Instead, pay attention to where they come from and where they go. There is a wire coming from upfront at the flywheel to a voltage regulator just behind the carburetor. My questions concern the rear batteries Jan 15, 2009 · According to my 1975 chassis wiring diagram, the 25 amp fuse runs the blower in all speeds but HI. If you want to run 10 gauge wire, you SHOULD replace the Onan breaker with a 30A. Along with some very good advice on installation and wiring of the speakers, Jim made sure I actually needed two solenoids for my '75 coach. Under normal operations it works Aug 20, 2015 · Try finding a 1978 Z87 GMC Motorhome parts book. Note: Everyone should have some type of over-current protection on the Excitation wire to the alternator. Gmc Motorhome Floor Plan Campervans Car Vehicle Angle Png Pngegg. Floor Plan Gmc Motorhome Campervans Jayco Inc Wardrobe Elevation Png Pngwing. GMCmotorhome. The reason your nichrome wire burn't up could be that you have a fault between the alternator output and the chassis battery. GEN light glowing. We have a 850 CCA starting battery up front and 2 six volt Trojan golf cart batteries in the rear. Aug 22, 2005 · The GMC Motorhome Forum is a place where owners and fans come together to have discussions and share information about the classic GMC Motorhome (VIN beginning with "TZE") and the adventures we have with them. When GM was upfitting motorhomes, they Oct 1, 2018 · The GMC Motorhome Forum is a place where owners and fans come together to have discussions and share information about the classic GMC Motorhome (VIN beginning with "TZE") and the adventures we have with them. Jan 15, 2009 · At least I knew the wiring to both was still good and operational. Contact us at the link below for advertising opportunities. Aug 17, 2021 · The control board gets its "Run" signal on pin 8. -- Ken Dec 16, 1997 · power wire from the alternator to the battery isolator device by installing an 8 ga. Jun 3, 2021 · My GMC is a '78 Transmode and has 2 vehicle batteries at the front charged via the diodes and shorted together by the boost switch. Roger Black had one on his coach. Dec 30, 2006 · >his old engine had an oil pressure switch wired to the distributor to turn off the >engine in case of lose of pressure. For registered users, a Google custom search option has been added that will search across several dedicated GMC Motorhome sites including this forum, GMCMI. But my 2 and 3 connector harnesses all have wiring to each connector. ;>) gene. The GMC Motorhome Forum is a place where owners and fans come together to have discussions and share information about the classic GMC Motorhome (VIN beginning with "TZE") and the adventures we have with them. This resistance wire has been known to overheat (perhaps due to bad diodes or a bad voltage regulator in the alternator). The standard in most of the coaches was actually a 60 amp, but it really is not advantage to go larger as the main engine and house bank can't use much more than that and if you push it, it will burn the single belt. The APC uses the GMC solution to the problem but also protects the Nichrome Resistance Wire. -- Aug 26, 1999 · The GMC Motorhome Forum is a place where owners and fans come together to have discussions and share information about the classic GMC Motorhome (VIN beginning with "TZE") and the adventures we have with them. They use much better components that the parts store rebuilds. Here is an excellent article on one-wire vs 3 wire alternators. Dec 27, 2022 · The benefit to the OEM 3-wire alternator is it starts generating power immediately upon engine start-up (this is the purpose of the exciter (nichrome) wire) and also gets a voltage regulation feedback signal from the inside the wiring harness where power is being drawn. wire. Replace OEM air bags or fit with aftermarket system. 5V at alternator white wire 17. Apr 6, 1999 · resistance wire, with the resistance wire supplying about 3/4 of an amp. pdf file and it is 32. After 40 years in the EE business, I understand the theory, but in the GMC I still suggest to run a wire to the load from Mother ground, the engine. Jan 8, 2018 · im pretty comfortable with automotive wiring, and GM wiring in particular, I hope this is a easy issue. The larger wire (white) should be on top. Which is why GM OEM'd a 3 wire alternator for the varying loads our coaches experience. A list of downloadable files/links of GMC Motorhome Electrical. Replace OEM house power supply if still fitted. May 14, 2020 · An alternator is a fixed voltage output device with the current limited only by the internal resistance of the alternator itself and the resistance of the wiring from the alternator to the loads. Aug 15, 2020 · Todd, The alternator is an 80 amp 27SI. Many people like to use single wire GM Delco alternators. That is the voltage feed-back wire from the wiring harness. So I am guessing that the old 4 prong relay that I replaced was not the correct original relay? the new relay is a Echlin AR109 5 prong Mar 22, 2023 · I'm installing a DC charger that can use a 12v signal to activate it. This puts the body connected to the engine because the house battery is connected to the frame/ body. May 2, 2018 · Greetings GMC friends; a couple years ago I was having problems with an alternator putting out 16. I've always had a amp gauge in my carsusually a 30amp or so. Dave S Place 73 Dodge Class A Chassis Wiring Diagram. Including wire/circuit diagrams, cruise control (Rostra), lightbulb usage, living on 12 volt and the battery charger. Feb 9, 2000 · Don't see anything wrong, but when my alternator lit the idjit light as we were pulling out for a 120 mile trek, I just wrapped solid wire under the two battery leads on the (ahem) isolator, 'cause it's easier to reach and has lotsa thread. Sep 14, 2021 · Motorhome Rehab Ranch - One Wire Alternator - GMC Motorhome If you liked this video and learned something valuable, support us by becoming a Ranch Hand on Patreon so we can keep making I've been busy with other projects but I need to get the Motorhome drivable and fixi I know some of you wonder where the RV videos are well here's a new one. Nov 4, 2022 · Inspect fuel tanks. Add APC kit to alternator wiring. The Alternator Protection Cable protects against the damage that a high reverse voltage would do to the alternator light and the Nichrome wire. 7 Volt drop within the isolator). Add EFI with two fuel pumps/filters at the rear. Dec 8, 2022 · A Brief History Of The Gmc Motorhome Everything You Need To Know. Note that I was able to get a lot of space around the exhaust pipe, I consider it necessary. will only charge the engine battery. net. I will be able to monitor alternator output from battery voltage and set a system warning, if voltage is less than 12. Consider MicroLevel wireless air bag controls. GMC supplied 80-amp alternators and wired them to charge the battery using a 10-gauge wire. Oct 2, 2017 · dictate a better overall wiring layout in the compartment. Billy might all so have it on his bdub web site. This wire provides the alternator voltage regulator with a voltage reading so that the voltage in the wiring harness stays relatively constant under all accessory loads and compensates for voltage drops (including the 0. You might dig through the GMC parts books looking for it. Oct 26, 2019 · I recently replaced my blower motor relay on my 1978. Mar 27, 2022 · To address the 9-5 conundrum, I would like to try wiring the starting-cycle 12v battery PIN 9 coil/fuel pump feed, that currently joins with one side of the fly-alt thru PIN 10, move that battery signal over to PIN 6. To use it, either click the "G" icon at the bottom of the search dialog or select the "Google search" tab in the search results. I know I can use an oil pressure switch, but it would be easier if there was a way to tie into something already existing Jan 3, 2007 · > the next option is a combiner. the way around this is to clip a jumper wire across the boost relay. For Sale 1977 Eleganza II. 13-15vac on each wire Apr 10, 2001 · alternator. Owner S Manual. Put in new alternator no voltage. The house batteries get drawn down until > they reach the 13v. When it Mar 27, 2022 · Before you do anything else, check the output voltage at the alternator and also at the 3 terminal Isolator. took out new alternator I thought it was bad. but as they say, do what you want to do. 5V or so, it should keep producing power. I don't have a wiring diagram for the '74s and Transmodes, so I can't speak for them. Various fixes are: - APC cable or equivalent (plugs in between the OEM wiring and the 2 pin connection to the alternator) Oct 5, 2016 · Apply dielectric grease to the 2 wire connector and plug it back into the alternator, the tab faces towards the front of the coach. I've seen a lot of "hot wire" damage on that wire. I confirmed this by this checking the voltage on the battery with the engine running, no increase in voltage, The center post of the Isolator was also showing zero volts, the High Fan switch was not working (needs Alternator power to run). Super Dec 20, 2005 · The GMC Motorhome Forum is a place where owners and fans come together to have discussions and share information about the classic GMC Motorhome (VIN beginning with "TZE") and the adventures we have with them. It also has a cable from the alternator down the drivers side to the point where I'll have my LiFePO4 batteries and DC-DC converter charger. My name is Pinkie and I’m a 1977 Eleganza II. or the buzz box charger. Add rear view camera. Quite often on automotive applications this sense lead is just connected directly to the alternator output stud a couple of inches away. com, and bdub. These alternators need to see elevated engine RPMs before they begin to charge. I just cleaned those up and added a new cable, so it seems unlikely. Sep 26, 2023 · Check that the connector contact labeled "2" on the 2 pin connector is clean and making tight contact. I unplugged the alternator connector to install the APC, and when I did, I noticed a loose wire on the connector. A pleasant surprise to me was that the "generator" warning light now goes out completely once the engine starts instead of dimly glowing all the time. 02H GENERATOR—145 AMP DELCOTRON (1978) 1117148 GENERATOR-145 AMP (w/RPO L04) It might be a one wire alternator. My alternator is a 100amp. Apr 2, 2005 · a combiner, I used the alternator output. Your best bet is to take your alternator to a reputable local rebuilder and have them go through it. Magnets rotate around the outside of the stator generating AC voltage on both ends of the coiled wire producing 26-30vac . the isolator will only allow the buzz box to charge the house battery and the alt. I've considered adding a momentary boost switch on the dash, but really Sep 29, 2023 · That is true on '73s and the wiring diagram shows this to be so, but on 75 through 78 the Boost Contactor (solenoids) are also powered by the House battery as shown in the wiring diagrams. TE167V102267. Oct 14, 2019 · This is a very good manual for the alternators used on the GMC. (consider the EBL/GM throttle body option). You should see about 15V or so at the output of the alternator. Ideally, I would like to get a signal only when the engine is running and the alternator is charging. Jul 8, 2007 · Good day to all. The old relay was a 4 prong relay. I do not remember if it was a one wire or remote sense alternator. California and Arizona, my owner will lose my garage space in Sedona AZ and I’m forced to find a new home, hopefully with someone who likes and appreciates me. It is in section 7. If you are using this type of single wire alternator, beware that you may not have the proper voltage provided to your system on initial start-up. I have it in a . his ignition 12 >volts comes from a wire that comes off the alternator. org is not affiliated with General Motors Corporation. Jun 6, 2023 · The #10 wire size was fine in an automobile, but in our coaches with the house batteries, and the extra loads, a heavier alternator and wire would have been a better choice. It seems odd that I'm getting more voltage at the battery than the alternator, and more voltage at the excitation pin than the Apr 29, 2011 · No - the GMC MH APC by Gene is to solve a problem where a specific alternator failure mode can burn up the dash wiring harness. Its purpose is to limit the electric current to the alternator field windings. I have never had a problem with the Onan start battery going dead. Now that most of us have replaced our alternators with higher output amperage, has anyone thought of increasing the size of the alternator wire? I am in the process of a total remake/rebuild and it is time to work on the wiring in the engine compartment as the rats really liked the Dec 3, 2022 · Regarding the light, nichrome wire and resistors, I understand the alternator will function without the #1 wire (#2 is the 12V), however the alternator won't start charging until ~2500 RPM. Matt, you know that the ONLY time current flows in the alternator exciter wire is when the alternator is not operating or there is a fault. Removed and bench Mar 28, 2002 · One of the gauges I just got (real reasonable) is a Stewart Warner 100amp. Does Mar 21, 2013 · electrical demands and low speed local driving. you wouldn't >ground it because that would ground the alternator. Dec 29, 2005 · > the alternator just puts out about 13 volts, and if the AGM > house batteries are at that level or higher, the alternator > does not charge. i can't figure out what the other pin on the oil switch did. from reading on the forums I should have 3-4 volts on brown wire on May 10, 2019 · 16. i can't figure out how it worked. > > In other words, the alternator is not replenishing what the > refrig consumes (roughly 20 amps DC). I ordered a pair of new solenoids from Jim B, along with some new stereo speakers for the new system SHE wanted for Christmas. Mar 18, 2010 · That includes both the wire from the Onan to the 50A outlet AND the shore power cord, which is often connected to the 50A Onan outlet. Replace all large battery cables. This wire connects to a double spade connector and a second wire goes over to pin 8 on the control board. Be careful, there are two sizes of 100 amp 27SI. LFP batteries want to see a constant current charge, so an LFP charger reduces its voltage to limit the current to the desired level while charging. range. Feb 8, 2023 · A one-wire alternator is typically used for applications where the alternator load is low and does not change much, such as an older tractor or stationary engine (irrigation pump etc). Vin No. The 75-76 schematic I have shows a brown wire going from the alternator #1 pin to the resistive wire leading to the "gen" light. > > Fin Beven > Pasadena, CA Mar 27, 2022 · FLYWHEEL ALTERNATOR: I am endeavoring to understand the Flywheel Alternator system in the Onan It appears to be a single wire that is coiled around into a STATOR ring. the wire tees off and goes to >the oil switch. The alternator's regulator uses the voltage on that contact to regulated the voltage in the wiring harness and compensates for voltage drop in the isolator and alternator output wiring. I am researching battery replacements for our 76 Eleganza II. Mar 7, 2020 · wire alternators such as described above. Straightforward 'in the door out the bottom' doesn't Oct 13, 2012 · Hi all, I recently purchased an APC. Jan 22, 1999 · be anyway to compensate for the voltage drop in the wire, which can be significant at times. Some owners have installed larger alternators without problem, but others replace the output wire with a larger gauge, such as 8-gauge or 6-gauge wire for a 100-amp alternator. It has a Progressive Dynamics 40 amp converter-charger with charge wizard. qboa lyldst vwqdbc qnmer jjoel rzbjd vojghw dohne mqzov pqtgsob