ALDJ253

I recently replaced both my Temp Gauge sensor and my Coolant Thermostat because the gauge was reading all the way to the "H" (Red) right when I would turn on my car. I checked my thermostat and realized that it was not working, because after awhile of driving, the return hose from the Thermostat Housing was flimsy and still pretty cold. So, I replaced it. I know the thermostat is working because after a little bit of driving the tube got firm (assuming from coolant pressure) and it got hot. I tried to bleed the cooling system, however when I used the nipple-shaped bleed screw, the coolant was coming out with a pretty steady flow. I also realized my fans are not working. Thanks to other threads, I have determined it to be a bad Fan Switch. so here are my concerns:

1) Will a bad Fan Switch cause my gauge to read "H" at start up?

2) Are there any other reasons why my Gauge reads at "H"? I bled my cooling system, checked the fluids, replaced the Temp sensor sender, and the thermostat (Not in that order).

3) I do not know if this can actually cause any problems, but my Air filter is needlessly filthy.

Some notes on the Fan: Both turn on with the AC turned on. Both also turn on when I jump the fans from the wire harness that is supposed to be connected to the fan switch. This is basically how I came to the conclusion of a bad Temp Switch

GhostAccord

1) No
2) What sensor did you replace, the 2 wire or 1 wire sensor?
3) Dirty air filter will cause poor throttle response and possibly cause your oil to get dirty faster if particles are getting through.

Depending on how long the temp gauge was pegged at max, you may have done some damage the the gauge itself. It is stated in the shop manual that prolonged grounding of the sensor wire (gauge reading max hot) can cause the gauge to fail.

ALDJ253

I actually had to drive someone somewhere at about 40 minutes continuous. The gauge lowered and went just below the halfway line. The things I replaced was the gauge sensor that goes to the dash. I think it just had to reset itself. I will update it if the car starts up at max heat next time I start it up.
Hopefully it just had tp reset. (Cross my fingers)

ALDJ253

Can it be the cluster? Just started her back up. Flew straight to hot

MAD_MIKE

Check your engine bay ground wires, and harness.
Then you may want to pull the cluster and inspect the wire harness there as well.
Might just be a loose/frayed connection.

ALDJ253

Sorry about the whole other thread. Do you know where the grounds for the harness are? I am pretty new to workign on cars, and don't have a lot of money, so getting a manual might be a pain for me.

DawolfCD5

If nobody tells you by tomorrow i can look it up in my auto class on ALLDATA

ALDJ253

Okay! Thank you!

I also noticed that whoever serviced the vehicle last also unplugged the Temp Gauge sender in hopes to not scare my parents with the temp gauge flying high(the one that goes to the dash). I think the connector for it might be loose or something because it looks pretty bad. I will try to post a picture onto this thread, so for those of you who are looking can please look at it in about 8 hours from now.

I also put "Teflon" tape on the top (away from the electrode) and left like the bottom half of the threads untouched. could this cause a problem? Should I just reinstall the Temp Gauge sender without the teflon tape?


Another add on to this is I do not even have to start the engine, with the key in the on position, the gauge flies high.

holmesnmanny

http://www.hondapartscheap.com/parts...er-pump-sensor

part number 15 is the coolant temperature sender(sending unit) for the cluster gauge
part number 17 is your fan switch and is likely bad
part number 4 is your thermostat

I would disconnect the sending unit connector and if it still goes to red then the problem is the gauge on the cluster.

I would also replace the fan switch and the thermostat with Honda OEM units since aftermarkets units often fail within a year of usage and aftermarket thermostats don't have the built in failsafe.

ALDJ253

I have already replaced my sending unit and thermostat both with Duralast :/
Also, the gauve does not turn on when I disconnect it from the sending unit.
What is the purpose of part 18? That is the sensor I have no idea what it is for.

GhostAccord

Parts 17 and 18 are your temperature switches for the cooling system fan control.

17 is temperature switch A
18 is temperature switch B






If you are looking for a manual Google, "Honda Accord CD7 CD9 Service Manual" and see if you can find the PDF file to download.

holmesnmanny

Did you turn the ignition to on when you disconnected it?

ALDJ253

I have another question, what in the world does ECT Switch B do? What the heck does it turn on?

ALDJ253

Yes I did. I will do it one more time

ALDJ253

Okay so, I started it up cold this morning a few minutws ago. The temp gauge took like 10 seconds then flew all the way to the H.

I disconnected the sending unit and the gauge didnt move at all, guessing that eliminates the cluster problem.

I also reconnected the sending unit with the engine running to try and wiggle the connection to get it to "fix" itself, but with no success.

Here is a link to a picture of the connection: https://imageshack.com/i/ghavpuj

ALDJ253

Okay so, I started it up cold this morning a few minutws ago. The temp gauge took like 10 seconds then flew all the way to the H.

I disconnected the sending unit and the gauge didnt move at all, guessing that eliminates the cluster problem.

I also reconnected the sending unit with the engine running to try and wiggle the connection to get it to "fix" itself, but with no success.

Here is a link to a picture of the connection: https://imageshack.com/i/ghavpuj

GhostAccord

Another thing to check would be the No. 1 (10 amp) fuse in the underdash fuse/relay box.

If the fuse is Ok and you disconnect the single wire temp switch and the gauge stays at H. There is ether an issue with the wiring shorting out/grounded somewhere or the gauge itself has shorted and is grounded out.

142 Ohms resistance = 53*C
94-32 Ohms resistance = 100*C
0 Ohms resistance = pegged hot

You will have to remove the gauge cluster and check the connections behind to see if it is the wiring or the temp gauge itself.

The complete instructions on how to remove the cluster is on that CD7-CD9 PDF file.

ALDJ253

When I disconnect the single wire sensor, the gaugedoesnt move at all. It stays below the blue as if the car was off

ALDJ253

I found a decent one for the wiring diagrams. Found out where all the grounds are for my wiring harness. So tomorrow when I get home, I will go to each ground and tighten them if they are loose, and possible clean them too.
Well, I also found another one that says differently. I have a 4 door and a majority of the manuals I am finding is for the Coupe verision.

http://hondatech.info/downloads/Auto/Manuals/Accord/
http://downloads.hondatech.info/Auto...Supplement.zip

The second link is the one I found the Wiring harness and grounds. However it says CC7 not CD7 or CD9. The CD7/CD9 Ones I have found are all coupes

Edit: I am going to try the Coupe version of a CD7/CD9

GhostAccord

The file you are looking for is;

Accord 1994 CD7 CD9 USDM JDM Service Manual





Hint:
spoonertuner.com/manuals

Sorry, due to Copyright reasons we're not supposed to post up the actual link to the file.

ALDJ253

Oh, did not know that.
The manuals for the 1994 Accord on Spoonertuner is for the Coupe. and the other one is for the aerodeck. Also the 1994 versions on Spoonertuner are either USDM or UK.
I used the Coupe version from www.hondatech.info
the file name is AbOVE.HOnda Accord CC7 Supplement. Closest one to my car I have found so far.

Using the CC7 supplement I was able to access some of what is supposedly the grounds.

I have no idea if this can be related to the gauge acting funny, but my upstream O2 sensor (Pre-Cat) is also bad according to my CEL Code. So far, it is the only code popping up.

So far my parts list looks like:
-O2 Sensor
-ECT Switch A
-ECT Switch B

So far what I have done:
-Checked the few Grounds I could
-Changed the ECT Sending unit (1 wire to the gauge)
- Changed Thermostat

What I have Realized:
-Thermostat opens when the idle slows down, so basically warmed up
- Sending unit to the gauge when UNplugged does not move at all, and remains at the "cold" Position
- Fans do not turn on at all, unless I turn on the AC (Bad A and B ECT switches)
- 30 seconds after the first start-up of the day, the "Cold Start", the temp gauge (when plugged in) soars to the Red, after that, the gauge will read hot when engine is off and key is at the on position.

I might try another method of burping the cooling system, I think I might still have some air in there somewhere.

ALDJ253

What in the world does ECT Switch B do?

MAD_MIKE

Note the temp range it activates. When the temps get above ECT switch A, then A is either non functional, or the car is getting hot. So B kicks on to increase air flow through the radiator with the secondary fan.

ALDJ253

Is there any other way to burp the radiator without the spill free funnel?

ALDJ253

The funnel is 40 and the fluid is like 15. According to the Pepboys website they fluch and fill for $60. Should I just go with that?