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Topic: Engine won't start (Read 1801 times) previous topic - next topic

Re: Engine won't start

Reply #25 –
Quote from: John44 –
Ignition solenoid is on the isolator panel, tested and both big lug terminals have voltage...
Are you sure you are looking at the IGNITION solenoid?  In most coaches, the ignition solenoid is located up at the front of the coach, either in the dash area in front of driver or behind the removable panel in front of passenger seat.

On the isolator panel, the big solenoids are usually either the AUX START solenoid, or the BOOST solenoid.

The BOOST solenoid has voltage on both big lug terminals all the time.  One side is start battery voltage - the other side is coach battery voltage.

1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Engine won't start

Reply #26 –
Will pull the drawings out tomorrow and double check,maybe the one I checked with both voltagese was the boost solenoid,
will look harder up front for a solenoid,thanks.We have our specific schematic from when we attended the driving school.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Engine won't start

Reply #27 –
Quote from: "Irish" –
You should add a trick-L-Charge for the start batteries to keep the voltage up,

Sad to say, Trik-L-Start and Amp-L-Start are no longer in production.

LSL Products / LSLProducts.com - Problem-Solving Gear & Gadgets
Learn every day, but especially from the experiences of others. It's cheaper!  - John C. Bogle

2000 U320 36' non-slide / WildEBeest Rescue
2003 U320

Re: Engine won't start

Reply #28 –
When you find the starter solenoid David, tell where it is because I don't see one in the front of the coach. Kick cover and under the raise up portion of the dash. I have 2 on the isolator panel at rear of the coach like you. I thought one of those 2 would be the starter solenoid. For others, David and I have the same year and make coach. 96... 270.
Dub McBride 1996 270

Re: Engine won't start

Reply #29 –
Dub,

In reply #20 I posted a link to a thread with photos of the ignition solenoid in a 1997 U270.  I would think your '96 U270 models would be similar...

Repeating - See first post in thread linked below:

Need dash solenoid I'd please

Instead of the single solenoid shown in photo, there might be two black plastic relays mounted in the same place.  If so, they perform the same function, but the ignition powered circuits are divided between them.
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Engine won't start

Reply #30 –
Will look again in morning,but we don't have a solenoid in that area.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Engine won't start

Reply #31 –
Quote from: John44 –
Will look again in morning,but we don't have a solenoid in that area.
If you don't find the single round metal IGNITION solenoid shown in the photo I linked to up above, then the alternative setup is two black plastic Bosch HD relays.  These two relays are pictured in the first post in the thread linked below.  AFAIK the transition from a single ignition solenoid to the dual relays happened around the 1998-99 model year.  I have never heard of any other type of setup.

Ignition solenoid on a u320

1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Engine won't start

Reply #32 –
Will check for those and give some feedback.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Engine won't start

Reply #33 –
Just checked,have the same exact ones as in post 31,will get some ordered.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Engine won't start

Reply #34 –
While you wait for replacements, it should be easy to check those relays with a multimeter.  Looking at the photo in Reply #31:

On each relay, there is one large terminal with red cables connected.  This terminal should be hot (12V) all the time.

There is another large terminal with black wire connected.  This terminal should only be hot when the ignition switch is ON.

NOTE:  I might have the two large terminals backwards.  The black wire might be hot all the time, and the red wire hot only with ignition switch ON.  Should be obvious which way it works once you start checking with multimeter.

The third (smaller) terminal has a white wire connected.  This terminal should only be hot when the ignition switch is ON.

Hard to see in the photo, but there is probably a 4th (smaller) terminal with a green wire connected.  This is the ground wire.

With multimeter, check the terminals (on each relay) with the ignition switch OFF, then turn ignition switch ON and check again.

If both relays function as described above, then they are OK, and your starting problem lies elsewhere.

1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Engine won't start

Reply #35 –
I think this is the appropriate wiring diagram for those Bosch relays.  If so, then I did have the two big terminals reversed.  The black wire (terminal 30) should be hot all the time.  The red wire (terminal 87) should be hot only with ignition ON.  86 is the white wire, and 85 is the green wire.





1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Engine won't start

Reply #36 –
Finished cleaning start battery terminals and started checking relays,they checked good so tried to start,started right up,could have been banging on the relay when taking off the wall but think it was probably the ground terminals,found the relays at
Texas industrial electric,in San Antonio,the part number on the old relay is,0 332 002 150 which supercedes to 0 332 002 168,
price is 64.50,only difference I can see is the new one has a resistor,will order 2 for spares,thanks for the help especially Chuck,
owe you some engine work,and yes the black wire is the hot one.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Engine won't start

Reply #37 –
Percussion persuasion, Dave, percussion persuasion!! (like I said) :))  :))  :))  :))  :))  :))  :))  :))  :))  :))  :))  :))  :))  :))  :))  :))
Nitehawk,  Demolition Lady, & our NEW master, Zippy the speeding BB cat.
1989 Grand Villa 36' ORED
Oshkosh chassis, 8.2 DD V8
2006 Saturn Vue AWD

Re: Engine won't start

Reply #38 –
Good information from Chuck, since we have you cornered maybe you can say what the 2 silver solenoids near the isolator are, i'm assuming one is the isolator solenoid so that leaves one that for me is unidentified. Again, 96 270. I can't find the answer on Beam alarm but it's probably there somewhere.
Dub McBride 1996 270

Re: Engine won't start

Reply #39 –
Quote from: Dub –
Good information from Chuck, since we have you cornered maybe you can say what the 2 silver solenoids near the isolator are, i'm assuming one is the isolator solenoid so that leaves one that for me is unidentified. Again, 96 270. I can't find the answer on Beam alarm but it's probably there somewhere.

I think the two solenoids on the isolator panel are for the boost and the remote start.
Doug W.
96 36' U270 CSGI #4946
04 Toyota Tacoma 4x4
PNW

Re: Engine won't start

Reply #40 –
One is the boost solenoid for sure,larger wires on both ends and both always hot.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Engine won't start

Reply #41 –
Makes sense Doug.
Dub McBride 1996 270

Re: Engine won't start

Reply #42 –
Quote from: Dub –
Good information from Chuck, since we have you cornered maybe you can say what the 2 silver solenoids near the isolator are, i'm assuming one is the isolator solenoid so that leaves one that for me is unidentified.
Dub,

I don't know what you mean by "isolator solenoid"  ??

On older coaches, if there is two silver solenoids on the isolator panel then one is the BOOST solenoid and the other is the AUX START solenoid.

John44 has positively identified one of his solenoids as being the BOOST solenoid.  That leaves the other one to identify.  If it is in fact the AUX START solenoid, then the test is to check the two large terminal posts with a multimeter.  With ignition switch OFF one large terminal should be hot and the other large terminal should not be hot.  Leaving the test lead on the not hot terminal, have someone turn the ignition key to the START position, and look for 12V on the terminal.  If you do see 12V (and the engine cranks over) then you have identified the AUX START solenoid.

However, the wiring diagram linked below seems to indicate that on the model years being discussed here, the factory installed a Bosch relay to perform the AUX START function (in place of the round steel solenoid).  You can see this relay on the diagram excerpt below in the top left corner of the area marked by the dotted line.

So if you guys have two round steel solenoids on your isolator panels, I guess for some reason they are set up like the older coaches.  Either way works fine!

https://www.foreforums.com/index.php?action=media;sa=media;in=3297

1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Engine won't start

Reply #43 –
Thanks Chuck. I've not had solenoid issues YET but while the subject was open it's a good time for pre school and bookmark for when it happens.
Dub McBride 1996 270