Ignition solenoid on a u320

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Ignition solenoid on a u320

June 05, 2018, 06:44:56 am

Where is the starter solenoid located on a 2000 u320? I thought it was located behind the panel in front of the passenger chair by the door but nothing in there looked like what I thought I was looking for. Here is a pic but I don't think this is it.

Keith

Re: Starter solenoid on a u320

Reply #1 – June 05, 2018, 08:21:53 am

Keith,

Are you looking for the STARTER solenoid, or for the IGNITION solenoid?

If it's the IGNITION solenoid you seek, then the two black things in the left photo are them. Yes, two of them. Bosch black plastic relays. They take the place of the round silver metal ignition solenoid that you often read about causing trouble for our members. The tandem relays split the power load. Each of them powers a separate DC bus on the circuit breaker panel.

If it's the STARTER solenoid you're looking for, then it is mounted on the starter, on the engine, at the back, where it is dirty and greasy.

Re: Starter solenoid on a u320

Reply #2 – June 05, 2018, 08:34:28 am

You are correct, ignition solenoid is correct. So these black relays are what go bad and keep the coach from getting power? These are the ones that people replace or carry spares? The one that has been mentioned is a blue sea, is mine the kind that goes bad? Trying to stay ahead of the game

Re: Ignition solenoid on a u320

Reply #3 – June 05, 2018, 08:40:59 am

Bosch makes good components, but they can fail like everything else. Stuff breaks. Wouldn't hurt to carry one or two spares of the same type, just in case. Some members have replaced the 2 Bosch relays with a single heavy duty solenoid, like the Blue Sea that you mention. The Blue Sea solenoid is thought to be very reliable and long lasting. I have one in our coach. Shop around for best price.

L Solenoid - 12/24V DC 250A - Blue Sea Systems

Re: Ignition solenoid on a u320

Reply #4 – June 05, 2018, 10:18:41 am

Is it difficult to rewire from the two units to one?

Re: Ignition solenoid on a u320

Reply #5 – June 05, 2018, 10:59:44 am

I just carry a pair of the relays, no reason to re-engineer something that works.

Re: Ignition solenoid on a u320

Reply #6 – June 05, 2018, 11:17:02 am

Quote from: GleamB – June 05, 2018, 10:18:41 am

Is it difficult to rewire from the two units to one?

If they are just "parallel" solenoids (i.e. each has one large-gauge wire from chassis battery and one out to "ignition hot" circuits AND each is switched by a signal from the ignition switch (small gauge wire), then absolutely no problem in going from two to one.

Be sure to put both "chassis battery source" wires on one of the large lugs and the two "out to ignition hot" wires on the other. Then you can use either or both small signal wires on the signal terminal. From the other small terminal on the Blue sea run a small gauge ground wire to any chassis metal or ground point depending on design of new solenoid unless the current relay has a ground wire to it in which case just use that/those wires for the ground.

Said another way, relays are pretty simple creatures:

Large lug FROM battery
Large lug TO what they supply
Small terminal from ignition source (12 VDC positive)
Small terminal to ground. Yes some metal-cased solenoids ground through their metal body to metal on mounting, but if no metal to screw to, can easily run a wire from one mounting screw to chassis ground.

I am also a big fan of the Blue-Sea solenoid-- rated for 1 MILLION cycles and well more amps than the unit will ever see. We have seen zero posts of failures of this unit, and many of us installed them. I installed one on our U240 17 years ago/about 100,000 miles ago and to my knowledge is still functioning perfectly. Mike, who has our coach now, would certainly post if there was a failure!

Re: Ignition solenoid on a u320

Reply #7 – June 05, 2018, 11:20:30 am

Quote from: GleamB – June 05, 2018, 10:18:41 am

Is it difficult to rewire from the two units to one?

I haven't done it, but it appears to be pretty simple. Looking at Keith's photo (above), it looks like each Bosch relay has 4 terminals. Black wire is the "control" connection from ignition switch, red wires are the "power" connection from battery, white "output" wires go to the circuit breaker busses, and I think there is a green ground wire hidden behind the other wires.

Disconnect battery power.

The Blue Sea solenoid has two wires: red and black. Red is the "control" power input, black is ground. Assuming the existing ring terminals are big enough, you would take the white wires off both Bosch relays and connect them to one of the threaded posts on the Blue Sea. The red wires off both of the Bosch relays would go on the other threaded terminal. The black wires from both relays would connect to the red wire on the Blue Sea, and the green ground wires would connect to the black wire.

Reconnect battery power. If you don't see any smoke, you're good to go!

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Ignition solenoid on a u320

June 05, 2018, 06:44:56 am

Re: Starter solenoid on a u320

Reply #1 – June 05, 2018, 08:21:53 am

Re: Starter solenoid on a u320

Reply #2 – June 05, 2018, 08:34:28 am

Re: Ignition solenoid on a u320

Reply #3 – June 05, 2018, 08:40:59 am

Re: Ignition solenoid on a u320

Reply #4 – June 05, 2018, 10:18:41 am

Re: Ignition solenoid on a u320

Reply #5 – June 05, 2018, 10:59:44 am

Re: Ignition solenoid on a u320

Reply #6 – June 05, 2018, 11:17:02 am

Re: Ignition solenoid on a u320

Reply #7 – June 05, 2018, 11:20:30 am

Re: Ignition solenoid on a u320

Reply #8 – June 05, 2018, 11:23:11 am

Re: Ignition solenoid on a u320

Reply #9 – June 05, 2018, 01:10:52 pm

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