Community Forums

Waiter21 · 04-02-2019, 11:15 AM

Every now and then when I went to start the engine, I'd turn the key and nothing.. It would always start on attempt number 2 or three. The previous owner warned me about this and said it was like that when he bought it..

Last week I had the steering column apart to change the shift lever OD button. so I decided to while I had things apart, I'd install a new ignition switch. The new switch cost $10 from Rock Auto.

The job took about 10 minutes, remove the connector, and then remove the two screws that hold the switch in.

I did a short write-up with a couple photos and links.

F53 replace ignition switch – 1999 Southwind 35S

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Bahamaniac · 04-02-2019, 08:32 PM

Nice job! I hope that it helps someone down the road. Thanks for posting!

cbilodeau · 07-15-2019, 06:43 AM

Quote:

Originally Posted by Waiter21

Every now and then when I went to start the engine, I'd turn the key and nothing.. It would always start on attempt number 2 or three. The previous owner warned me about this and said it was like that when he bought it..

Last week I had the steering column apart to change the shift lever OD button. so I decided to while I had things apart, I'd install a new ignition switch. The new switch cost $10 from Rock Auto.

The job took about 10 minutes, remove the connector, and then remove the two screws that hold the switch in.

I did a short write-up with a couple photos and links.

F53 replace ignition switch – 1999 Southwind 35S

..

Many thanks for pictures and all the details.

Just ordered the Ignition switch.

I can only start if I short my starter solenoid. Seems like my Ignition switch has a problem. I tested my DTR and I receive like 15V on pin 10. And my DTR does what it is suppose to do to send pin 10 to pin 12. Then my pin 12 of DTR send this signal to the solenoid. This 15V is probably ghost power with almost 0 amperes since it can't activate my solenoid. So I am all mixed up and just ordered the Ignition Switch.

cbilodeau · 07-15-2019, 11:01 AM

When I write DTR I mean: Transmission Range Sensor TRS or DTR Sensor.

The DTR Sensor on the transmission must be adjusted correctly so that when the transmission is in P or in N the circuit between pin 10 and 12 will be closed. This system is to make sure we can NOT start the starter when in "Drive".

The DTR sensor can be ajusted by making sure the lines are together when the transmission is in N like on this picture:

See this thread to read about the DTR.

The pins for the connector on the DTR Sensor are :

The wire connected to pin 12 goes to the Starter Solenoid to activate it. Normally pin 10 receive power from the PCM when we start the key.

How I did my testing of the DTR sensor:

1 - I disconnected the connector on the DTR.
2 - Then when the motorhome is in P I test with a ohmmeter that pin 10 on the sensor let the power go to pin 12. This was ok and tells me that the DTR sensor is not the problem.
3 - When someone try to start with the key I check pin 10 on the DTR sensor harness to see if I receive power on start. It's weird, I got 15 volts and was expecting 12.4V. So I have ordered a new Ignition Switch. I suppose my 15V was a ghost signal with 0 amperes since my solenoid is not activated by it.
4 - I tested to make sure the wire on the harness for pin 12 correctly goes to the solenoid. I did this verification by sending +12V on the this pin and the starter worked. This means this wire between the DTR sensor and the Starter Solenoid is ok.

Since I don't have the wiring diagram for my F53 I could not test the wire on the DTR sensor harness for the pin 10. Maybe this wire is bad. Maybe the Ignition Switch is bad. So next week when I receive my Ignition Switch from Rockauto I will see if my problem is solved. If the problem is not solved then I will be looking for the wiring diagram for my F53. I have ordered the Repair manual that Rockauto sells for my F53. Hope it will show the wiring.

I must say that the first action I did before testing my DTR sensor was to clean all my various grounds cables (engine and chassis ground), battery cables, starter connectors, solenoid connectors, ground and Battery cables on the BCC (Battery Control Center) etc. I wanted to make sure it was not a loose connection or a bad connection or a dirty connector that was causing my problem.

N.B.: You can click on the links to see the parts I bought on rockauto.

cbilodeau · 07-19-2019, 09:46 AM

Just received the repair manual. There is more than 60 pages out of probably 4000 to 6000 pages just for ignition-start. Eveybody should have it. Full of pictures. Very easy to diagnose! See the link on my previous post for this Repair Manual 1999 on Rockauto. 27$CAD or probably 20$US. They have probably your year model too!

My previous posts were right about DTR testing. In the repair manual they show also how to test PCM to Ignition switch connections. But when the Ignition switch is so old, so easy to change and so cheap it's not a bad idea to just change it right away. Took 10 minutes to remove. I should receive new one next tuesday.

Waiter21 · 07-19-2019, 11:13 AM

Quote:

My previous posts were right about DTR testing. In the repair manual they show also how to test PCM to Ignition switch connections. But when the Ignition switch is so old, so easy to change and so cheap it's not a bad idea to just change it right away. Took 10 minutes to remove. I should receive new one next tuesday.

Yah, that's kind of how I look at it.. Its 20 years old, its cost $10. If it fails while on the road, I'm dead in the water. So its one of those things that I replaced as a preventative measure.

I went through mine and did this with most inexpensive sensors, i.e. cam position, crank position, speed, OD shifting stalk, etc..

cbilodeau · 07-19-2019, 12:35 PM

Quote:

Originally Posted by Waiter21

Yah, that's kind of how I look at it.. Its 20 years old, its cost $10. If it fails while on the road, I'm dead in the water. So its one of those things that I replaced as a preventative measure.

I went through mine and did this with most inexpensive sensors, i.e. cam position, crank position, speed, OD shifting stalk, etc..

In fact if someone has an old motorhome and doesn't know the age of the various parts, then when he need to change the starter he should change also the Solenoid Relay for 15$, the DTR for 20$ and the Ignition Switch. He would then be ok for another 10 more years for the starting system.

cbilodeau · 07-29-2019, 10:26 AM

Does anybody know where the Clutch Pedal Position connector is on the F53? It is also called the Clutch Interlock Switch. It prevent starting the motor when the clutch is not in use.

I received and changed my "Ignition Switch" but it did not solved my problem.

So now that I have the Repair Manual I need to go tru all the STEPS to troubleshoot my problem.

The repair manual wants me to test the wire from the CPP to the transmission DTR sensor. The CPP is the Cluth Pedal Position harness connector. Since we don't have a Clutch Pedal (automatic transmission) they simply put a Jumper Connector I guess. I need also to test a wire from the Ignition Switch to the CPP.

Here is a picture of the harness connector that I am looking for:

cbilodeau · 04-25-2020, 04:18 PM

i did not fix this issue yet. I should work on it in the coming weeks.

cbilodeau · 04-26-2020, 01:04 PM

Someone wrote me this:

Hello I saw a previous post on 7/29/2019 where you were having similar problems with your RV starting. I have replaced the ignition switch, solenoid, and still will not start unless I jump the solenoid. There is no current at the solenoid and none at the DTR, but there is starting current at the ignition switch. What was your resolve to fix your starting problem.

Here is my answer to his private message:
In the past I had a problem with my Battery Control Center. I had good voltage on my voltmeter and I did not understood for 1 month. Then I realized that even if I had current, the wire at the nut was dirty and even if the voltage was showing 12.6v I concluded that the amperage was probably too low because there was a big resistance cause by the dirt.

I = V/R where I is amperage, V is voltage and R is resistance.

This formula show that the bigger the resistance, the lower the amperage will be. So a bad connection can lower the amperage but keep the Voltage perfect at 12.2 to 12.8v.

In fact the formula can also be written like this V = I x R. It means that the bigger the resistance will be, the lower the voltage could be.

So with our ignition switch we both probably have a dirty fuse, or a dirty-old relay (I thinks there are two relays), a dirty relay base connector, a dirty ground, a dirty-rusted wire or something like this.

If ever I can not find the faulty component after changing the relays and fuses, I could simply add a Relay to the circuit. How do we do this? We take the current from the Ignition switch and we send it with ground to the two coils wires of the new relay. Then we use the switch inside the relay to send a very good 12v from a fuse to the DTR wire.

On this image: https://www.swe-check.com.au/images/...atic_diode.gif

The Ignition 12V+ goes to pin 86, a ground goes to 85. We send a very good 12+ from the motorhome to pin 87 and the pin 30 goes to the DTR.

Any 12V relay would do the job. There are plenty on aliexpress (45 to 60 days delivery) and also on eBay, amazon, Radio-Shack, or any car parts store.

I would take a small relay so that the ignition 12V+ current is good enough for the next 20 years to activate it.

cbilodeau · 04-27-2020, 03:51 PM

In my previous post I give the picture of a 4 pins relay with diode protection. The diode protection is not necessary. We could also use a 5 pins relay.

or

https://images-na.ssl-images-amazon....duhEL._AC_.jpg

RELHUB · 04-29-2020, 05:38 AM

Quote:

Originally Posted by Waiter21

Every now and then when I went to start the engine, I'd turn the key and nothing.. It would always start on attempt number 2 or three. The previous owner warned me about this and said it was like that when he bought it..

Last week I had the steering column apart to change the shift lever OD button. so I decided to while I had things apart, I'd install a new ignition switch. The new switch cost $10 from Rock Auto.

The job took about 10 minutes, remove the connector, and then remove the two screws that hold the switch in.

I did a short write-up with a couple photos and links.

F53 replace ignition switch – 1999 Southwind 35S

..

ALWAYS a GREAT post
Thanks for the information