ignition problem

[clarksgocamping]

I have a 2000 Safari Zanzibar 300 cat diesel, On a recent trip while traveling at highway speed I noticed my tach dial jumping around, and suddenly the motor stopped, I jiggled and turned the key off then on and the motor started and we drove all the rest of the way home. We unloaded the coach and when I went to move it, it would not start. I remembered that sometime back when I went to get it out of storage I had trouble. When I turned on the key the lights that normally go on, do not. I hear the solenoid  switch click but no lights and the tach and spedo don't jump around as they are supposed to. I replaced the ignition switch checked the wires that I can see. Still nothing, Help

[hermanmullins]

Clark, Check your ignition solenoid.

Herman

[clarksgocamping]

I hear it click how do I check it?

[wolfe10]

Agree.

If nothing that normally only works with ignition on works (dash HVAC fan, Allison shift pad, etc) check the IGNITION SOLENOID.  The key/ignition only provides the "signal" to close the ignition solenoid.  The power for all those ignition-hot circuits comes through the solenoid.

[wolfe10]

To check the solenoid:

It will have two large lugs.

One has battery voltage all the time (between them and good chassis ground/clean metal).

The other large lug only has voltage (exact same voltage) only when the key is on.

With key on, do you have 12+ VDC to both large lugs?

 

[clarksgocamping]

there 4 posts 2 with large red wires and 2 with small white wires on the set of red with the key on I get 13.8 on the top wire and nothing on the bottom wire same with the small white wires 13.8 top 1.2 on the bottom

[wolfe10]

OK, 13.8 on one large post is from chassis battery

Other large red should have same with ignition switch on.

The two small terminals:

One should be 12 VDC positive with ignition on, nothing with ignition off

Other small one is ground. 

SO, from small terminal to small terminal with ignition OFF= 0 VDC.  With ignition on  12+ VDC.

What do you get at small terminals?

With that info we can help with further troubleshooting.

[wolfe10]

Several "work arounds".  If stranded and need to get going, let us know and we can get you going.

[clarksgocamping]

I am not stranded we're home. As advised by another I crossed the two large posts with a wire, everything lite up therefore he determined solenoid was bad ,do you agree?

[wolfe10]

YES, correct.

But, be very careful using a jumper wire.  That battery side is usually unfused and contacting any metal would result in a dead short.

Be sure you replace it with a CONSTANT DUTY solenoid of at least the amp rating of the present one.  This is a case where bigger IS better.  And, usually 200 amp constant duty solenoids are not that much more than 100 amp ones.  But have much more contact surface, so last longer.

Another excellent but not inexpensive upgrade that I use on both boats and my motorhomes is a https://www.bluesea.com/products/9012/L_Solenoid_-_12_24V_DC_250A

Rated for 1 MILLION cycles, 250 amps continuous. Amps to hold in closed position .13 amps.

[clarksgocamping]

Thanks for all your help I will reply after I install the solenoid

[clarksgocamping]

My motorhome is fixed. I tested as instructed and found the solenoid to be bad. installed the new solenoid and all is well.

Thanks to all for your excellent advice. What a great feature of belonging to FMCA it's worth the price of membership alone.

It's comforting to know there is expert help so easy to access.

Thanks Again Dave Clark

[bkman99]

Have similar problem so I went to parts store and bought a replacement ignition solenoid. The large lugs weren't long enough to mount the 3 cables required on the left side. The lugs are shorter and are a size smaller than my original. What now?

 

[wolfe10]

bkman99,

Welcome to the FMCA Forum.

Two choices:

1. Take it back and get one with longer lugs.

2.  Buy a short cable and install an isolator post (or buss bar) where those three cables plus the new one from the isolator to ignition solenoid can be combined. Something like this: https://www.westmarine.com/buy/blue-sea-systems--power-post-single-terminal-connectors--P009_273_004_010 They come in various post sized-- choose one that your current cable ends will just go over.

Make sure that the solenoid is CONSTANT DUTY and rated for at least the same load as the OE-- here, a higher amp rating is better (more contact surface and/or better contact material).

[bkman99]

Thanks for the suggestions. The extension is what I had in mind, but I hadn't found the parts needed. I'll let you know how it works out.

[wolfe10]

Easy to find in any marine store. 

[manholt]

West Marine is one!