Northoak Posted May 25, 2021 Share Posted May 25, 2021 Hey y'all, talked to someone with a fairly affordable 74 Chinook for sale near me that I'm hoping to check out tomorrow. They said that the battery will not charge even though they put in a new battery and alternator. I'd have to jump it and drive it for about an hour without stalling or else I could end up stuck on my way home! I do have a few spare batteries I figure I could bring with me in case I stall. I'm fairly versed in the Toyota way since I've owned an 83 pickup for years. I'm brainstorming how to troubleshoot it in case I end up buying it. I figured I'd bring a multi meter to see how many volts the are going to battery when running. I also figure I could pick up a voltage regulator to bring with since I can just return it to O' Reilly if I don't use it. Does the voltage regulator affect charging or rather the voltage going to the components from the battery? There is no second battery in this rig at the moment. I'm also wondering if anyone knows if the second battery completes the charging circuit? Does anyone know what some other likely culprits are for a 74 Chinook that is not charging? Any suggestions are appreciated. Thanks! Quote Link to comment Share on other sites More sharing options...
WME Posted May 25, 2021 Share Posted May 25, 2021 I "think" that this vintage truck has a separate voltage regulator, was it replaced? Check the voltage (13.5v) at the alternator output. See if there is an isolator. If there is follow the + wire from the alternator to the isolator. Then follow the + wire from the battery. Connect both wires to the same terminal on the isolator. Check the voltage again on the ganged terminal and the battery. All the components have been bypassed so it's all about the wire. The missing battery is moot. When you get home we can help you troubleshoot better. Quote Link to comment Share on other sites More sharing options...
fred heath Posted May 25, 2021 Share Posted May 25, 2021 (edited) First..... don’t think of the chinook as a motorhome. It’s a 1973-74 Toyota pickup with a camper body attached. This will make trouble shooting much easier. The truck is 47 years old. Who knows what modifications previous owners have made to the electrical system. Get a basic help book like Haynes or Chiltons, a good voltmeter and start your troubleshooting. This truck is known as a first generation Hilux. The systems are pretty basic, but if you’re not used to doing troubleshooting, best to get some help. A good source for early Toyota help is “toyotaminis.com”. Its forum section is filled with members having the same truck as yours. Unfortunately, there are very few members on this site with pre 1980 motorhomes, although we’re still the best. Edited May 25, 2021 by fred heath Quote Link to comment Share on other sites More sharing options...
linda s Posted May 25, 2021 Share Posted May 25, 2021 There is a Chinook group here toyotachinook@groups.io | Home It's not very active but when someone asks for help they seem to always come through. They know the early trucks well Linda S Quote Link to comment Share on other sites More sharing options...
Scott iv Posted May 25, 2021 Share Posted May 25, 2021 Agree with WME, look for a battery isolator if the vehicle has a separate battery for the camper part. If there is an isolator use a multi meter to see whether the alternator is charging both sides of the isolator. If it is charging just one of the two sides, connect the side that is charging to your truck battery. Quote Link to comment Share on other sites More sharing options...
Northoak Posted May 26, 2021 Author Share Posted May 26, 2021 Thanks y’all! Gonna check it out tomorrow, wish me luck! Good thought on checking the isolator/bypassing it for now! Quote Link to comment Share on other sites More sharing options...
Northoak Posted May 27, 2021 Author Share Posted May 27, 2021 Went and checked it out today. It wont start on its own even with a fully charged battery I brought. Starts great with a jump from a running truck. Alternator is charging up to about 13.5 volts when I check the running voltage on the battery. The strange thing is that when I turn the key to the on position without turning the truck over and the voltage on the battery drops drastically to about 10v on the fully charged bat. I tried this with the owners battery as well and it dropped to about 5v. I tried checking for a parasitic drain by pulling each fuse out one at a time but the voltage drain when you turn the key to on persisted. I also disconnected the second battery and confirmed that the two batteries did not have continuity between them. I'm unsure what is pulling enough voltage to keep the engine from turning over with a charged bat? Any tips are appreciated, I think I'm gonna buy it tomorrow even though it is a can of worms! Quote Link to comment Share on other sites More sharing options...
Scott iv Posted May 27, 2021 Share Posted May 27, 2021 Sounds like you will be following wires for a short/ damaged wiring. I replaced the battery terminal wires and terminals on mine, and ground wire to the fuse box under the hood. Quote Link to comment Share on other sites More sharing options...
WME Posted May 27, 2021 Share Posted May 27, 2021 Check the grounds. Should be a large wire from the battery- to the truck chassis. Clean the contacts. Add a same size wire from the chassis ground point to the engine. Quote Link to comment Share on other sites More sharing options...
Northoak Posted May 29, 2021 Author Share Posted May 29, 2021 Ended up cleaning up all the connections with a dremel, swapping the battery and disconnecting the old cabin battery from the idolator and the chinook is running! I brought it home yesterday 🙂 Lots of work to do, thank you for the help! Quote Link to comment Share on other sites More sharing options...
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