Foretravel Owners' Forum For owners and Fans of Foretravel Motorcoaches September 15, 2025 ...

Paully's 1992 U300 6V92

September 03, 2017, 02:37:57 pm

Checked out Paul's Coach yesterday found some system problems. I know from past experiences start with the simple stuff first, electrical connections.  Some of you may have some ideas for Paul
correcting the issues that I missed. Here's a few

Alternator putting out 14.75 volts to isolator, that's is far as it goes, just to that post. Suggested cleaning all Connections and retesting, If isolator is bad I suggested he replace with a marine 2 way switch.

6 rib belt on the Hydraulic pump, Idler pulley only running about an 80% of the belt. Suggested he purchase an 8 rib and have a couple spares on hand. Not sure if the idler pulley can be shimmed for 100% contact?

Fast idle control seems to be inoperative,  does the Detroit have that option?

Dometic Fridge won't stay lit on gas but stays lit longer than if circuit board was bad. The shielding near the burner area seems to be excessively hot for as well insulated as it is. To hot to touch for more than a few seconds. I think it may be shutting down for this reason could the thermal couple detect excessive heat? Suggested he disassemble and clean flue and burner area.

Hot water heater and front furnace won't fire. Thinking connections or circuit board.

Misters installed on side radiator. Has mystery switch on dash... When activated it seems to change RPM on hydraulic fans,  slight difference in sound, is that possible?  Water pump for misters seems to be toast but maybe we haven't found the correct switch.

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Re: Paully's 1992 U300 6V92

Reply #1 – September 03, 2017, 03:29:31 pm

"Fast idle control seems to be inoperative,  does the Detroit have that option?" When I asked about it I was told that we do NOT have that feature.

"Hot water heater and front furnace won't fire. Thinking connections or circuit board." Could well be. Could also be a problem with the propane supply. A couple of times the front furnace wouldn't light, the blower just ran and ran. I started checking things and found a loose connection at the furnace. Tightened the screw and all was good. There IS water in the hot water heater, isn't there? My coach has only propane hot water (no electric).

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Re: Paully's 1992 U300 6V92

Reply #2 – September 03, 2017, 05:34:40 pm

Fast idle only works if you have a Pro-Link 9000. It's the first part of the injector test but works well as a stand alone 1000 rpm fast idle.

If the pulleys have 8 ribs, you need an eight rib belt. If one of the pulleys has only 6 ribs, then you need a six rib belt. As I remember, the twin fan/horizontal radiator models use a 8 rib belt, the vertical radiator with a single fan uses the 6 rib. Send me a photo. Having all the pulleys correctly aligned with all of the ribbed belt on the idler pulley is VERY important.  See my old posts on how to do it and for the belt part number.  Foretravel has the wrong part number and the wrong number of ribs on some of the U300s.

The whole mount is adjustable where it bolts to the block. The pump pulley is keyed and will slide in and out. The idler/tensioner needs to be adjusted so the vertical angle is the same as the crank and hyd motor pulleys. See my old posts for how to adjust it.

Clean and jump all the water heater sensors including pulling the main connector and using a electrical cleaner on it before buying a new board. Corrosion is frequently the problem.

All GVs are prone to the fridge compartment catching fire. Check for rodent nest/dust bunnies and modify compartment like I did. OEM fridge is probably close to the end of it's life.

Pierce

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Re: Paully's 1992 U300 6V92

Reply #3 – September 03, 2017, 06:08:01 pm

"All GVs are prone to the fridge compartment catching fire. Check for rodent nest/dust bunnies and modify compartment like I did. OEM fridge is probably close to the end of it's life." When we first looked at our coach the seller told us the original refrigerator was dying, if not already dead. It had died by the time we took the coach out for a real trip. We had already decided that when the original refrigerator died we would replace it with a residential unit, so after we got home from that trip we removed the old refrigerator, bought and installed a new apartment-size residential refrigerator. Of course, that meant upgrading the old inverter and chargers/converters (I have two). Not cheap, but well worth it. Then, of course, we had to replace the old 8D house batteries.

Welcome to the fun of upgrading these wonderful old coaches.

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Re: Paully's 1992 U300 6V92

Reply #4 – September 03, 2017, 07:26:01 pm

Indeed... thanks for the help. At least now I know where to start! I should add that Tim suggested the regulator on the LP.

And Doug was suprised my LP sniffer was still lighting up but sucpects its toast as it would not alarm with a non lit lighter at the sensor.

Pierce... Pic on the way. Ty ty

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Re: Paully's 1992 U300 6V92

Reply #5 – September 03, 2017, 08:17:33 pm

Paul,

Thanks for the photo. You have the correct 6 rib belt installed for your model. Probably the easiest is to fit a quarter inch spacer behind the tensioner to space it out a little. The belt does not have to ride on the center of the roller but should not go over the edge.  Stick a 3/8" or 1/2" breaker bar in the square hole in the tensioner arm, pull it hard and remove the belt. Then you can remove the tensioner. You will also need to make sure the angle is the same for the tensioner compared to the crank pulley and the pump pulley and may need a shim to change the angle slightly. Ours was 3 degrees off. You may need a new belt also as there appear to be cracks in yours. I recommend the Gates Fleet Green Stripe belt. If the belts are aligned properly, it will last forever. Buy a couple online as they are expensive otherwise. I did turn my tensioner on it's side and oiled it a little. It's OEM at 100K. Attached is the photo you sent me. Thanks again for the photo as it tells all. As you can see, the factory didn't do any favors when they installed the hydraulic system. Yours is exactly like ours and others that I have seen.

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Re: Paully's 1992 U300 6V92

Reply #6 – September 03, 2017, 08:53:31 pm

Yes, your vertical photo makes it clear. New tensioners will have the belt riding on the same place so don't get your hopes up with a new tensioner. I think I counted the number of ribs correctly on your belt. It should have the same number as the crankshaft pulley has. Here are my photos that show exactly how to correct any angle discrepancy between pulleys. The belt shown is for the 8 rib crank pulley and won't fit yours. The "8" in the number should be "6" for yours. You can also see the small washer I installed to correct the roller angle. Note: the coach can be at any angle for these measurements. The degrees you read must be the same.

Pierce

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Re: Paully's 1992 U300 6V92

Reply #7 – September 03, 2017, 08:55:46 pm

Forgot the belt.

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Re: Paully's 1992 U300 6V92

Reply #8 – September 04, 2017, 08:54:58 am

Agree that the tensioner needs to be spaced out.  But, remember that the detent pin MUST fit securely in the hole in the mounting bracket.  That is what allows the spring to develop tension.

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